Abstract

Radon gas was previously presented to be a good tool as a proxy for pre-seismic precursory before earthquakes, especially when the detector is deployed a few meters underground in regions of high seismic activity. In this paper, we present a fiber optic-based detector that can be deployed underground and assist in the measurement of radon gas temporal concentration variations. The sensitivity of the fiber-based sensor is enhanced due to Fabry-Perot resonator realized within the fiber. The sensing principle is related to the impact of the alpha particles released from the surrounding radon gas on the optical transmission parameters of the fiber. By incorporation of WDM filters along the fiber sensor, the dispersion of the radon's radiation damage along the deployed fiber can be allocated.

© 2021 Optica Publishing Group under the terms of the Optica Open Access Publishing Agreement

1. Introduction

Radon is a noble gas (it has no interactions between the molecules and the molecules are of zero volume). Its main features are its very high radio activity (5.7 × 1015 Bq/gr), and its imperceptibility by the senses, as it is at once tasteless, odorless, and colorless. Radium is a decay product of Uranium-238 and its byproduct - Radon - is constantly being generated by the radium present in rocks, soil, water and other materials. It is derived from the rocks and soils used in certain building materials. Apart from being dangerous to humans and the environment, there is also high motivation to detect the presence and concentration of the radon gas in the ground since high radon gas concentrations indicate an increasing earthquake. Radon and its progeny (radon decay products – RDP) are carcinogenic at certain gaseous concentrations [1]. The higher the concentration, the higher the likelihood of cancer. Radon natural decay chain is the main source of natural radioactivity in the Earth's crust and since it is only 0.7% in nature the fraction is much lower [2,3]. As such, its release from rocks and soil, can therefore potentially, as a gas, be correlated with geophysical events (i.e. earthquakes). As one of its subsequent compounds (or sub-compounds), radon itself undergoes radioactive alpha decay, emitting high-energy alpha particles that can be measured and tracked by nuclear detectors. Rn-222 is the most abundant isotope (99.3%) common mainly due to its abundance in nature as a parent isotope and has a half-life of 3.8 days, transforming into Po-218 which is also a short-lived of 3.05 min and is a high energy alpha emitter [4].

Radon-222 is the only gas in the radioactive decay chain of uranium therefore it may attach to aerosol (dust) particles, producing an inhalable radioactive mixture [4]. It penetrates homes through soil diffusion processes, through cracks and openings in walls and floors and/or home plumbing systems (water, sewerage, etc.) and concentrates mainly in basements and ground floors [5]. Radon exposure accounts for approximately one-tenth of lung cancer cases in developed countries [6].

The detection of radon gas indicates a good correlation with geophysical events. Its presence can be associated with one of two possible phenomena: it can originate from a deep source in the earth or is a local phenomenon that it has wandered from a distant area by some flowage movement because of geodynamic event [7]. Because of this, physical temporal variations in the measurement of radon gas in water and soil have been expected as earthquake-predictive value, a phenomenon that has been well studied [8,9]. Research suggests that increases in the concentration of anomalous radon gas may be a function of crustal, strain and deformation processes along active seismic faults, which increase prior to earthquakes [10]. However, to achieve good earthquake-predictive information, it is necessary to monitor the radon concentrations continuously, and over wide physical conditions and preferably underground. This correlation has been studied experimentally and via the construction of mathematical models [11,12].

In the extensive literature review conducted in this study, many similar studies were studied that dealt with radon gas measurements and the attempt to create an earthquake prediction tool from it. In most performed studies, radon concentrations vary significantly as a function of distance and accordingly measurement is difficult and challenging. The use of optical fiber in the system built in our study measures the degree of attenuation of light and improves the sensitivity of the measurement. It can be seen that an average attenuation of 0.004 µw per each meter per Bq/l [13,14].

Research has already been done to develop a remote sensor for continuous measurement of radon using fiber optics. Successful first results were obtained which showed an identification of natural radon appearing in a container with a high presence of uranium oxides [15].

Naturally Occurring Radioactive Materials (NORM) and manmade [16], increased human exposure to ionizing radiation and become with sufficient exposure harmful to humans. Many nuclear detectors are used today to determine the quantity, and in many cases the spatial distribution of alpha emitting gasses (as radon-222) and/or fissile nuclides as radium-226, uranium-235, uranium-238, plutonium-238, plutonium-239 and americium-241, in a wide variety of materials or geological surface media as soil, rock or alluvium. Plutonium does occur naturally, but at very low concentrations. Indeed, it is all but unobservable, except by very sensitive modern analytical techniques. The reason that plutonium (and other transuranic elements) is so rare in nature is that being radioactive, they decay with a characteristic half-life. The main problem with all the alpha particle detectors is the short distances of these particles in air, of only 2–3 cm. Therefore, the detection of the alpha contamination is traditionally carried out using hand-held alpha radiation detectors, which require direct interaction with the alpha particles in very close proximity to a contaminated surface, around 1 cm.

This makes detecting alpha radiation time consuming, in the order of hours for one site (location where radon gas concentration is measured). It also requires sometimes the use of PPE (personal protective equipment) to prevent ingestion by personnel in close proximity to alpha sources, including the danger of inhalation if disturbed, contaminated material becomes airborne. Hence, it is desirable to find a new method of AlphaGuard particle detection which: can be carried out at a distance; is operated remotely; scanning based; completed on site; portable; and possible through clear/translucent barriers (e.g., glove box sides or viewing windows).

The development of optical fiber technology and industry, the use of fiber as a device to measure and detect toxic, flammable, and radioactive gases has a huge potential for prevention and mitigation of public disasters. Low weight, small size, high sensitivity, usability over long distances, resistance to extreme environmental conditions, shielding from external electromagnetic influence and relatively low costs are among the research motivation to develop the optical fiber capability as an alpha particle's detector. It could be used in many applications to name a few: Environmental radioactivity monitoring, health physics personnel monitoring, nuclear fuel cycle processing and decommissioning, nuclear forensics, and earth sciences.

The effect of light radiation on optical properties and the properties of optical fiber has been quite well researched. The effect of radiation damage on the structure of the optical fiber can reduce light transmission [17]. Optical defects can be either by the activation of already existing defects or by ionization and/or atomic displacement mechanisms [18]. In the presence of optical fiber pollutants, increases in radiation passage losses are significant and the classification of pollutants in terms of concentration, base location will determine whether these losses are permanent or temporary.

The effect of light radiation on optical fibers and especially on their optical properties as a proven and effective means of measuring radiation has been extensively studied in the past. The radiation damages the structure of the optical fiber and depending on the light that passes through it, it usually decreases depending on the time / intensity of the radiation / building materials and other additional parameters that affect it.

This study focused on the use of optical fibers for detection and measurement of radon. There has been some research on optical solutions. This line of inquiry begins with the question of how the high energy alpha particles’ irradiation act on different components of the fiber optics. The polymer-clad, the fused-silica core optical fiber and how the induced attenuation depends on the wavelength of light passing through the fiber [19]. In this research we examine the impact degree of the radiation dose rate on the total optical transmission, as well as the wavelength dependence. We also address whether there is a dynamic but stable transmission recovery in this type of fiber. The optical properties of fiber waveguides can be degraded by exposure to ionizing radiation, primarily through the generation of color centers in the fiber core. Color centers are a type of optical fiber infection because they absorb light. This issue has been studied in the past, mainly from the aspect of the wavelength of light across the optical fiber as a result of the loss rate.

Thus, optics exhibit a great deal of promise in the detection of radon gas both for health issues, and for the more challenging task of earthquake prediction. In one past research case, the radon was measured with relatively high sensitivity, several miles away from an earthquake zone [20]. In this study we aim to increase the complexity of the system by using an optical cavity and an interferometer (Fabry-Perot), thereby improving sensitivity and building tools for measuring changes in radon gas concentration at high-resolution in the subsurface media.

Other research directions in the past were the gamma radiation, the treatment and the action of the operation that was performed in this radiation by fiber optic. The high energy emission of the alpha particle radiation usually of Po-218 and Po-214 has been tested in the past and measured already in a leading study that offered a passive low-sensitive radon detector, the LR-115 film [21].

The LR-115 passive detector is the basis of a solid-state nuclear track detector (SSNTD) whose use for integral radon measurements has been well established. This technique requires calibration by comparison [22].

2. Materials and methods

In this study, we introduce a new research method for measuring radon concentrations based on the use of optical cavity and Fabry-Perot interferometer. The constructed measurement system presented, aims to work continuously, and to measure changes in radon concentrations by exposing bare optical fiber, core and cladding.

The system layout shown in Fig. 1 is used for the developing of a fiber-optics alpha particle detector system and includes various components. The setup enables to produce, in a controlled manner, a measured quantity of alpha particles in a definite isolated transparent glovebox in which an optical fiber is installed and exposed to the alpha particles’ radiation. The source for the alpha particles is a commercial Ra-226Cl2 (a product of https://www.eurostandard.cz/products.html) that contained in a stainless-steel cylindrical case supplied with a ball valve at the end. At the beginning of each experiment, the radon is releases and begins to disperse in the sealed isolated space of the glovebox in a homogeneous way using the air diffuser. It takes a few hours to build up a secular equilibrium (In nuclear physics, secular equilibrium is a situation in which the quantity of a radioactive isotope remains constant because its production rate (due to decay of a parent isotope) is equal to its decay rate.) between the radon gas and its solid radioactive decay products (RDPs) which are emitting alpha particles that disperse as aerosols in the limited space.

 figure: Fig. 1.

Fig. 1. Schematic description of the experimental system. a) A Sealed radon glovebox. b) Ra-226Cl2 (radium chloride) radioactive source of radon-222 that serves as a source of alpha particles. c) a fiber optic system exposed to the α-particles inside the sealed chamber. d) The α-particles flux in Bq/m3 as measured by the Alpha guard detector. e) Air diffuser for homogeneous dispersion of the radon gas in the chamber. f) and g) optical spectrometer and light source /monitoring devices.

Download Full Size | PPT Slide | PDF

It is the situation in which the half-life time constant, $ {\lambda _d}$ (d-daughter), of the product Polonium-218, is shorter than that of the constant of the parent, Radon-222, (${\lambda _p}$ of parent). The daughter product is produced but it decays rapidly. However, the system arrives to the point where the rate of decay of the daughter product equals to the production rate of the parent product. When equilibrium is reached, the activity of the parent product and the activity of the daughter product are approximately the same. In

$$\frac{{d{N_d}}}{{dt}} = {\lambda _P}\cdot {N_0}\cdot \; {e^{ - {\lambda _P}t}} - {\lambda _d}\cdot {N_d}$$
the $\frac{{d{N_d}}}{{dt}}$ is the change rate of the daughter nuclei number (blue line), and λ$\frac{{d{N_d}}}{{dt}}$ is the decay rate of the daughter (red line) as seen in Fig. 2 and the ${\lambda _P}\cdot {N_0}\cdot \; {e^{ - {\lambda _P}t}}$ is the decay rate of the parent.

 figure: Fig. 2.

Fig. 2. The plot is of activity versus time for the parent and daughter products in secular equilibrium between the radon gas and it’s first solid radioactive decay product (RDP).

Download Full Size | PPT Slide | PDF

The experimental system is based on exposing the core and cladding of an off the shelf single mode fiber. The process of exposing the fiber was done such that the buffer and the jacket were removed from a section of one meter fiber. This procedure made the exposed fiber becomes very fragile and therefor it needed to be harnessed to a wood stick in order to preserve its structure. Since the core and the cladding are two silica having different refractive indexes per each, where the core has higher refraction index in respect to the cladding, the light propagates within the core due to the law of total internal reflection. The fiber was kept straight on the wooden support, so no bending occurs. It is important to note that removing the buffer and the jacket didn’t change the fiber’s characteristics so bending of the fiber can be done at a sufficiently small radius.

While exposing the bare section of the optical fiber, Alpha particles randomly damage the core and cladding and give rise to degradation increase. It can be seen in Fig. 3 that the alpha particles randomly strike the entire exposed area and as a function of time the damage to the fiber accumulates.

 figure: Fig. 3.

Fig. 3. Schematic description of the exposed fiber.

Download Full Size | PPT Slide | PDF

The overall system is presented in Fig. 4 and it is built such that is can measure in two ways. One is based on pulses signal and the other is on continuous mode. In the pulse measurement, the input is a 1 us pulse with duration of 9 us (meaning duty cycle of 10%).

 figure: Fig. 4.

Fig. 4. Schematic description of the system.

Download Full Size | PPT Slide | PDF

The initial energy that enters the system in each pulse is the same as in the continuous mode and independent of the system.

The second is the continuous mode which mean that in each measurement the overall losses are presented in the average decrease in power. The fiber system includes 6 main parts: 1-Fiber mirror, 2- Coupler (Y1), 3-Coupler (Y2), 4-Delay, 5-Sensor and 6-Fiber mirror. The amplifier is used to amplify the pulsed signal such that sufficient SNR will be obtained. It measures the signal directly.

The system allows the return of pulses and thus functions as a resonator. This method allows to accumulate the optical degradation of the exposed fiber section. The energy calculations presented ahead are for the pulse mode and take into account the possible routes as well as the losses obtained on the various energy passes.

The working assumption in this research over the lifetime of the fiber ranges around a number of weeks and even few months without damage, as Radon gas concentrations are very low in the soil unless geological activity occurs.

Due to the use of a coupler in the system, there are several energy splitting of the energy path. In each split a relative share of the incoming energy is divided accordingly. Both splits have been configured for the system and taken into account:

$${\gamma _H} = 98\%- \; \; light\; passes\; through\; the\; 98\%\; path$$
$${\gamma _L} = 2\%- light\; passes\; through\; the\; 2\%\; path\; \; \; \; \; \; \; $$
$${A_I} = P\cdot {\gamma _L}\cdot {C_{loss}}$$
$$\; {A_0} = {A_I}\cdot {\gamma _H}\; ,\; \; {A_{0\; scope}} = {A_I}\cdot {\gamma _L}$$
where P is the energy generated from the pulsed light source (Note that this energy pulse is before the first split point in the system as seen in Fig. 4), ${A_I}$ is the pulse energy after passing the first FC/PC connector attenuation (${C_{loss}} - \textrm{is the loss due to the FC}/\textrm{PC connectors}$) in addition to the 2% attenuation of passing the incoming Y coupler arm (${\gamma _L})$. The ${A_0}$ is the initial pulse energy at the entrance to the fiber resonator and $ {A_{0\; scope}}$ is the pulse light reaching the measuring detector (scope).$\; {A_1}$ is the pulse energy after the first round i.e. a complete cycle of the light in the system. ${D_{loss}}(t )$ is the loss over time due to alpha damage which correlate to alpha particle impinging the exposed fiber. The losses on the connectors are estimated at 0.3 decibels (${C_{loss}} \approx 0.3\; dB\; )$, ${M_{loss}}$ is the fiber mirror losses due the light reflected from the fiber mirror (${M_{Reflected}} = 99\%)$.

A0 is the pulse energy at the entrance to the first round and A1 is the pulse energy after the first round i.e. after a complete cycle in the resonator. Equation (4) presents the calculation of the losses in the fiber resonator due to the different loss elements in the pulse light path.

$$\begin{aligned}{A_1} &= {A_0}\cdot ({C_{loss}}\cdot \gamma_H^2\cdot C_{loss}^2\cdot {D_{loss}}(t )\cdot {C_{loss}}\cdot {M_{Reflected}}\cdot {C_{loss}}\cdot {D_{loss}}(t )\cdot C_{loss}^2\cdot \gamma_H^2\cdot {C_{loss}}\nonumber\\&\quad\quad \cdot \gamma_H^2\cdot {C_{loss}}\cdot {M_{Reflected}}\cdot {C_{loss}}\cdot {\gamma_H} )\end{aligned}$$
and
$$\begin{aligned}{A_{1\; scope}}& = {A_0}\cdot ({C_{loss}}\cdot \gamma_H^2\cdot C_{loss}^2\cdot {D_{loss}}(t )\cdot {C_{loss}}\cdot {M_{loss}}\cdot {C_{loss}}\cdot {D_{loss}}(t )\cdot C_{loss}^2\nonumber\\&\quad\quad\cdot \gamma_H^2\cdot {C_{loss}}\cdot \gamma_H^2\cdot {C_{loss}}\cdot {M_{loss}}\cdot {C_{loss}}\cdot {\gamma_H}\cdot {\gamma_L}\cdot {C_{loss}} )\end{aligned}$$

The research assumption was that at each entrance to the coupler, an energy loss is obtained and therefore the total energy loss in each round is:

$${K_{pass}} = 1 - {K_{loss}} = \gamma _H^7\cdot C_{loss}^{10}\cdot M_{loss}^2\cdot {\gamma _L}$$
$${L_R} = {A_1}/\; {A_0} = {K_{loss}}\cdot {D_{loss}}^2(t )$$

The values in the table are calculated and are not the result of an experiment. We know the usual losses for each item in the system and hence the calculation for each cycle are performed within the resonator.

Where ${K_{loss}}$ is the loss per resonator round that comes from the time independent elements while $ {L_R}$ is the total loss in each round taking into account the exposed fiber contribution. Table 1 presents the calculated properties of the loss due to different Gamma degradation percent. The losses calculations are based on the 850 nm wavelength as presented in the experiment results of this paper. In this experiment, we examined the best affected wavelength which gives the degradation due to alpha exposure. Four wavelengths were used as in the optical industry. This means that this wavelength is not the optimal one for such sensor and there might be a better and more sensitive wavelength than the 850 nm used in the overall experiment.

Tables Icon

Table 1. Calculated properties of the loss due to different Gamma degradation percent.

The losses increase over time, as seen in Table 1, at the % column, since the optical fiber becomes less transparent. In each full path cycle of light, it decreases accordingly as seen in Fig. 5. The calculations we made in Table 1 indicate an increasing loss, because the comparison is always in relation to the beginning, which means that we always compare to a fixed value that enters the system. When a pulse enters the system, it undergoes an optical attenuation, and in each period of time, we receive an additional optical power attenuation which combines fixed full path attenuation and a time varied attenuation. In order to increase the radon detection resolution, we focused on the forth replica of the pulse injected to the resonator, since we found it suitable in its SNR (see Fig. 5). The system measures every pulse that enters it at the beginning and treats it as a primary pulse and therefore it is a real measurement with no effect at all on the continuation of the energy in the system.

 figure: Fig. 5.

Fig. 5. The light intensity pulses Vs. time. In each test the first pulse is acquired together with its 4-5 rounds pulse. The grey part is coined A, B, C is the degradation due to the alpha particle damage in each resonator round.

Download Full Size | PPT Slide | PDF

In each complete cycle, meaning back and forth of the light (energy) a fixed loss of 42.3% is obtained in relation to the measurement of the energy at the entrance to the system. The first reading uses as reference reading and the system calculates and measures the gap in relating to the reference replica pulse. This gap is the degradation of the system. The pulses at the input to the system are constant but in the timeline a decrease is obtained because the cumulative scheme is of the total decreases as shown in Fig. 5 (the grey area) and the optical attenuation of the light is constant. The light pulses are constant and as time passes, a decrease in intensity is obtained, which means that the attenuation decreases in the timeline. The contribution of the exposed area of the fiber is very significant and its main contribution is that a cumulative effect is obtained i.e. as the amount of vulnerability increases accordingly a cumulative effect is obtained which leads to an increasingly weakened attenuation ability (as seen in Fig. 6).

 figure: Fig. 6.

Fig. 6. The attenuation percentages versus time in each pulse replica.

Download Full Size | PPT Slide | PDF

The pulse at the input is always the same in intensity and is the reference, instead we are looking for the gray area in the graph that expresses the growing degradation. The ratio of the degradation to the intensity of the pulse increases because the damage to the fiber accumulates.

The contribution of the exposed area of the fiber increase over time as more optical attenuations are made due to more and more damage to the fiber so that in practice the level of optical attenuation increases. The length of the fiber (514 meters) gives the interval between the pulses which makes it possible to distinguish between the different pulses and investigate the magnitude of the degradation.

3. Results

In order to select the best wavelength suitable for the experiment, we did a preliminary test experiment by measurement of 4 different wavelengths: 850, 1310, 1490 and 1550 nanometers. It helped us determine which wavelength is most sensitive to alpha particle damage in the core fiber. The result is presented in Fig. 7 and clearly indicates that the biggest change as a function of time was by using the 850 nm.

 figure: Fig. 7.

Fig. 7. Examining of best wavelength impact.

Download Full Size | PPT Slide | PDF

Hence, we had to take into account the effect of pressure, humidity and temperature on the Alpha measurement inside the Radon experimental box as seen in Figs. 8 and 9. The reason is that when temperature rise the density of the radon gas reduce and the pressure rise which affect the amount of radon particles in the closed volume. Figures 8 and 9 show this affect in 24 hours window starting at 19:00 in the evening while the setup worked continuously without interruption. It seems that there was an instability of about 20% in the general radiation flux due to the variations in the environmental temperature and pressure conditions [23].

 figure: Fig. 8.

Fig. 8. Measurement of the radon build-up flux in Bq/m3 and versus temperature (Celsius) and pressure (Bar), within the experimental glovebox versus time.

Download Full Size | PPT Slide | PDF

 figure: Fig. 9.

Fig. 9. Measurement of the radon build-up flux in Bq/m3 and the humidity, within the experimental glovebox versus time.

Download Full Size | PPT Slide | PDF

After approximately two hours the radon within the glovebox reached a secular equilibrium with his first decay product, the Polonium-218. During the same experiment the effect of pressure seems noticeable, but altogether the radon fluctuation level is less than 20%.

The refraction index and hence the losses of optical fibers depend also on temperature. In optical sensors it is sometimes common to control and stabilize the temperature of the fiber sensors. However, when examining changes in fiber’s loses due to significant thermal variations, one can find that they are very small and temporal. The transmission of the fiber due to the damage from the external radiation is accumulative and permanent.

Further examination of an environmental parameter that may affect the experiment, humidity, shows in Fig. 9 that even this environmental parameter does not materially affect the total amount of the radon and the alpha particles content by more than 15%.

An analysis of the last two figures shows that there is a time window of 4 hours between 14:00 noon and 19:00 in the evening where the behavior is linear, therefore there is no point in calibrating the change as it is relatively constant.

The diffusion coefficient D is also sensitive to humidity. Several correlations have been developed to evaluate this quantity from the data on moisture content. The radon diffusion coefficient in residue (${D_r})$ maybe also estimated using the empirical formula provided by Rogers and Nielson that is given as:

$${D_r} = {D_{MA}}{n_T}\exp ({ - 6m{n_T} - 6{m^{14{n_T}}}} )$$
where, DMA is the molecular diffusion coefficient of radon in air; r is the total porosity which may be calculated from nr = 1-(ρbg); ρb is the dry bulk density ;ρg is the grain density of the residue matrix (∼2700 kg/m3) and m is the fraction of pore space filled with water and is given by the relation m= ρbθd/100ρw nT, where θd is the moisture content on a dry weight basis and ρw is the density of water(kg/m3) [24].

In this research we ignore the effect on alpha particles that encounter water molecules and the experiment performed was done in controlled conditions. In addition, the phenomenon of absorption of alpha particles in the air is relatively negligible.

The radon gas container was open inside the measuring chamber at time 0 as shown in Fig. 10 and in about a minute and half, the gas dispersed and reached its steady state in the entire space. It can be seen that as soon as the chamber reaches a saturation state after about an hour and a half, the amount of change is corrected, and significant optical fiber damage is obtained.

 figure: Fig. 10.

Fig. 10. Measurement of the radon build-up flux in Bq/m3 and the reduction in the optical response within the optical fiber.

Download Full Size | PPT Slide | PDF

From the analysis of the results of Table 1 and Fig. 10, the result of ${A_3}$ is a decrease of about 14%. The losses (${D_{loss}}$) are increasing and the calculation is always in relation to the initial value i.e. in relation to a constant value so it can be seen that the value of ${A_3}$ is relevant in this experiment. Please note that there are several theoretical limitations to the proposed method:

  • a) Deformation of the soil - Natural forces in the soil can damage and destroy the fiber, there is also self-movement of the soil (erosion).
  • b) Temperature – If significant thermal differences occur, they can affect the fiber.
  • c) Time - The measured degradation is only in relation to the previous point in time, i.e. initially the level of transparency is high and the degradation in each cycle is more significant but after a number of cycles the same degradation will affect the light transmission ability in the fiber and the degradation is not linear. In practice we will find that the ratio between the amount of gas and the damage to the fiber changes all the time and this ratio decreases as time passes until at the end of the process, i.e. at the end of the fiber life. Thus, periodic calibration is needed.

Our estimate in the study over the life of the fiber ranges around a number of many weeks and even several months without damage since radon gas concentrations are very low in the soil unless geological activity occurs. A worthy direction for further research is to measure the concentration of radon versus fiber life but the purpose of our current research was only to validate the capability of providing an alert.

4. Discussion

After the built up of the fiber sensor and extracting the respective concentration changes, we take this research another step and aim to incorporate locating the approximate position to the radon source. We base our technique on using Bragg filter along the exposed fiber.

In the basic concept the delay time gives time interval between one pulse and the pulse returning from the mirror. The way back of the pulse is delayed in the face of a long fiber that was inserted into the system at a length of 514 meters, i.e. a delay of 1028 meters (back and forth), all this in view of the separation ability of the scope.

The delay gives a sufficient time interval between one pulse and another. This delay is double for each pulse, the reciprocating motion of the light pulse means that a delay of 0.003 seconds is obtained.

$$T = \frac{{2\cdot Delay}}{C}$$

The schematic sketch of the optical part is depicted in Fig. 11. In this figure one may see the Fabry-Perot resonator generated using spectrally sensitive Bragg gratings. If the fiber was injected with many wavelengths simultaneously, (λ1,…λN), each wavelength will encounter its Fabry-Perot resonator in a different location along the fiber based sensor.

 figure: Fig. 11.

Fig. 11. Schematic sketch of the optical sensor.

Download Full Size | PPT Slide | PDF

Thus, the measurements performed per each wavelength can not only sense radon signature but also indicate where the nuclear track was physically located. Regarding the Fabry-Perot resonator, the finesse, F, means that each photon is passing through the resonator approximately F times. The finesse, F, is also the factor that enhances the sensitivity since the sensitivity is associated with the optical transmission. The relation between the finesse and the optical reflectivity, R, of the Bragg grating, is defined as follows:

$$F = \frac{{\pi \sqrt R }}{{1 - R}}.$$

Please note that we proposed using the spectrum to identify the location of the radiation. We use CW illumination for that but time of flight is a feasible direction instead of using the spectrum. However, the detection hardware in the case of time of flight is more complicated, and the location resolution will depend on the temporal width of the transmitted pulses. The CW approach has simpler and cheaper hardware, but the time-of-flight approach is indeed interesting, and it can be very relevant for our future research with the fiber.

5. Conclusions

The optical fiber has been shown to be used as a tool for sensing alpha particles radiation and hence it can be used to detect radon concentration. The sensing is obtained by measuring the damage and degradation in the optical transparency of the fiber depending on the time of exposure to the alpha particles emitted from the radon gas.

Fiber based optical sensors were tested before as appears e.g. in Refs. [13,14] In our experiments we were able to obtain an improved sensitivity in compared to those fiber based photonic sensors.

An important conclusion that emerges from this study is that it is possible to design an optical system that can be buried underground to save the installation of the current used, expensive, and complicated in operation radon alpha detectors. The capacity of the optical fiber is damaged linearly and until a durable state is reached in which the optical fiber is no longer usable, it allows preparation time. Another conclusion from the study is that it is possible to design an optical prediction system that is based on a fiber whose level of damage will be significant and thus it will be possible to easily detect even low radon gas concentrations in the soil.

Please note that in our research we assumed that attenuation affects obtained in the non-exposed regions of the fiber are not an error. The working assumption was that the jacket reduces fiber vulnerability but what is relevant is that the fiber is buried in the ground and that the measurement is done on the overall fiber’s transmission characteristics.

Disclosures

The authors declare no conflicts of interest.

Data availability

Data underlying the results presented in this paper are not publicly available at this time but may be obtained from the authors upon reasonable request.

References

1. A Report of a Task Group of the International Commission on Radiological Protection, “Protection against Radon-222 at Home and at Work,” ICRP Publication 65. Ann. ICRP 23 (2) (1993).

2. R. L. Fleischer and A. Mogro-Campero, “Mapping of Integrated Radon Emanation for Detection of Long-Distance Migration of Gases within the Earth: Techniques and Principle,” J. Geophys. Res. Solid Earth 83(B7), 3539–3549 (1978). [CrossRef]  

3. IARC Monographs on the Evaluation of Carcinogenic Risks to Humans, “Man-made Mineral Fibres and Radon,” Vol. 43, IARC Working Group on the Evaluation of Carcinogenic Risks to Humans, Lyon (FR): International Agency for Research on Cancer (1988).

4. R. W. Field, D. J. Steck, B. J. Smith, C. P. Brus, E. L. Fisher, J. S. Neuberger, C. E. Platz, R. A. Robinson, R. F. Woolson, and C. F. Lynch, “Residential Radon Gas Exposure and Lung Cancer: The Iowa Radon Lung Cancer Study,” Am. J. Epidemiol. 151(11), 1091–1102 (2000). [CrossRef]  

5. A. da Rocha Lino, C. M. Abrahão, M. P. F. Amarante, and M. Rocha de Sousa Cruz, “The Role of the Implementation of Policies for the Prevention of Exposure to Radon in Brazil—a Strategy for Controlling the Risk of Developing Lung Cancer,” Ecancer 9, 572 (2015). [CrossRef]  

6. S. Otto Wolfbeis, “Fiber-Optic Chemical Sensors and Biosensors,” Anal. Chem. 80(12), 4269–4283 (2008). [CrossRef]  

7. F. Mireles, J. I. Dávila, M. L. García, J. L. Pinedo, and H. López, “Evaluation of Efficiency Calibration Parameters of the LR-115 Radon Detector,” Health Phys. 98(2), S63–S68 (2010). [CrossRef]  

8. A. Negarestani, S. Setayeshi, M. Ghannadi-Maragheh, and B. Akashe, “Estimation of the Radon Concentration in Soil Related to the Environmental Parameters by a Modified Adaline Neural Network,” Appl. Radiat. Isot. 58(2), 269–273 (2003). [CrossRef]  

9. A. Deb, M. Gazi, and C. Barman, “Anomalous Soil Radon Fluctuations – Signal of Earthquakes in Nepal and Eastern India Region’s,” J. Earth Syst. Sci. 125(1), 1–11 (2016). [CrossRef]  

10. H. Zafrir, Y. Ben Horin, U. Malik, C. Chemo, and Z. Zalevsky, “Novel Determination of Radon-222 Velocity in Deep Subsurface Rocks, and the Feasibility to Using Radon as an Earthquake Precursor: Radon-222 Velocity in Deep Subsurface,” J. Geophys. Res. Solid Earth 121(9), 6346–6364 (2016). [CrossRef]  

11. H. Zafrir, S. Barbosa, E. Levintal, N. Weisbrod, Y. Ben Horin, and Z. Zalevsky, “The Impact of Atmospheric and Tectonic Constraints on Radon-222 and Carbon Dioxide Flow in Geological Porous Media - A Dozen-Year Research Summary,” Frontiers in Earth Science 30, 433 (2020). [CrossRef]  

12. R. D. Evans and G. F. Knoll, “Remote optical detection of alpha particle sources,” Journal of Radiological Protection 24(1), 75–82 (2004). [CrossRef]  

13. M. Mirhabibi, A. Negarestani, M. Agha Bolorizadeh, and M. Reza Rezaie, “A new approach for radon monitoring in soil as an earthquake precursor using optical fiber,” J. Radioanal. Nucl. Chem. 301(1), 207–211 (2014). [CrossRef]  

14. D. Guimarães, C. S. Monteiro, Luis Peralta, and S. M. Barbosa, “Fiber optic sensor for radon monitoring: proof of concept,” RAD 2018 conference proceeding (2018).

15. C. S. Monteiro, L. Coelho, S. M. Barbosa, and D. Guimarães, “Development of a New System for Real-Time Detection of Radon Using Scintillating Optical Fibers,” in 26th International Conference on Optical Fiber Sensors, OSA Technical Digest (Optical Society of America, 2018), paper WD5.

16. B. K. Rejah, “Natural Occurring Radioactive Materials (NORM) and Technologically Enhanced NORM (TENORM) Measurements on Oil Field in North Region of Iraq,” PhD thesis (2015). https://www.researchgate.net/publication/307639330_Natural_Occurring_Radioactive_Materials_NORM_and_Tech nologically_Enhanced_NORM_TENORM_Measurements_on_Oil_Field_in_North_Region_of_Iraq#fullTextFile Content

17. E. J. Friebele, K. J. Long, C. G. Askina, M. E. Gingerich, M. J. Marrone, and D. L. Griacom, “Overview of Radiation Effects In Fiber Optics,” In SPIE Proc. Vol. 0541, 70–88.(1985).

18. B. Zmazek, L. Todorovski, S. Dzeroski, J. Vaupotic, and I. Kobal, “Application of Decision Trees to the Analysis of Soil Radon Data for Earthquake Prediction,” Appl. Radiat. Isot. 58(6), 697–706 (2003). [CrossRef]  .

19. M. Namvaran and A. Negarestani, “Measuring the Radon Concentration and Investigating the Mechanism of Decline Prior an Earthquake,” J. Radioanal. Nucl. Chem. 298(1), 1–8 (2013). [CrossRef]  

20. N. Akchurin, E. Kendir, S. Yaltkaya, J. Damgov, F. De Guio, and S. Kunori, “Radiation-hardness studies with cerium-doped fused-silica fibers,” J. Instrum. 14(03), P03020 (2019). [CrossRef]  

21. A. El-Taher, “An overview of Instrumentation of Measuring Radon in Environmental Studies,” J. Rad. Nucl. Appl. 3(3), 135–141 (2018). [CrossRef]  

22. M. Tirmarche, J. Harrison, D. Laurier, E. Blanchardon, F. Paquet, and J. Marsh, “Risk of Lung Cancer from Radon Exposure: Contribution of Recently Published Studies of Uranium Miners,” Ann. ICRP 41(3-4), 368–377 (2012). [CrossRef]  

23. M. J. Buckler and M. R. Santana, “The Effect of Temperature on Fiber Loss And Pulse Delay Distortion For An Exploratory Fiber Optic Cable,” Optical Fiber Transmission II Technical Digest, (Optical Society of America, 1977), paper WA2.

24. W. J. Goodman, E. A. Bahaa Saleh, and M. C. Teich, “Fundamentals of photonics,” 2nd edition, Wiley (2007).

References

  • View by:

  1. A Report of a Task Group of the International Commission on Radiological Protection, “Protection against Radon-222 at Home and at Work,” ICRP Publication 65. Ann. ICRP 23 (2) (1993).
  2. R. L. Fleischer and A. Mogro-Campero, “Mapping of Integrated Radon Emanation for Detection of Long-Distance Migration of Gases within the Earth: Techniques and Principle,” J. Geophys. Res. Solid Earth 83(B7), 3539–3549 (1978).
    [Crossref]
  3. IARC Monographs on the Evaluation of Carcinogenic Risks to Humans, “Man-made Mineral Fibres and Radon,” Vol. 43, IARC Working Group on the Evaluation of Carcinogenic Risks to Humans, Lyon (FR): International Agency for Research on Cancer (1988).
  4. R. W. Field, D. J. Steck, B. J. Smith, C. P. Brus, E. L. Fisher, J. S. Neuberger, C. E. Platz, R. A. Robinson, R. F. Woolson, and C. F. Lynch, “Residential Radon Gas Exposure and Lung Cancer: The Iowa Radon Lung Cancer Study,” Am. J. Epidemiol. 151(11), 1091–1102 (2000).
    [Crossref]
  5. A. da Rocha Lino, C. M. Abrahão, M. P. F. Amarante, and M. Rocha de Sousa Cruz, “The Role of the Implementation of Policies for the Prevention of Exposure to Radon in Brazil—a Strategy for Controlling the Risk of Developing Lung Cancer,” Ecancer 9, 572 (2015).
    [Crossref]
  6. S. Otto Wolfbeis, “Fiber-Optic Chemical Sensors and Biosensors,” Anal. Chem. 80(12), 4269–4283 (2008).
    [Crossref]
  7. F. Mireles, J. I. Dávila, M. L. García, J. L. Pinedo, and H. López, “Evaluation of Efficiency Calibration Parameters of the LR-115 Radon Detector,” Health Phys. 98(2), S63–S68 (2010).
    [Crossref]
  8. A. Negarestani, S. Setayeshi, M. Ghannadi-Maragheh, and B. Akashe, “Estimation of the Radon Concentration in Soil Related to the Environmental Parameters by a Modified Adaline Neural Network,” Appl. Radiat. Isot. 58(2), 269–273 (2003).
    [Crossref]
  9. A. Deb, M. Gazi, and C. Barman, “Anomalous Soil Radon Fluctuations – Signal of Earthquakes in Nepal and Eastern India Region’s,” J. Earth Syst. Sci. 125(1), 1–11 (2016).
    [Crossref]
  10. H. Zafrir, Y. Ben Horin, U. Malik, C. Chemo, and Z. Zalevsky, “Novel Determination of Radon-222 Velocity in Deep Subsurface Rocks, and the Feasibility to Using Radon as an Earthquake Precursor: Radon-222 Velocity in Deep Subsurface,” J. Geophys. Res. Solid Earth 121(9), 6346–6364 (2016).
    [Crossref]
  11. H. Zafrir, S. Barbosa, E. Levintal, N. Weisbrod, Y. Ben Horin, and Z. Zalevsky, “The Impact of Atmospheric and Tectonic Constraints on Radon-222 and Carbon Dioxide Flow in Geological Porous Media - A Dozen-Year Research Summary,” Frontiers in Earth Science 30, 433 (2020).
    [Crossref]
  12. R. D. Evans and G. F. Knoll, “Remote optical detection of alpha particle sources,” Journal of Radiological Protection 24(1), 75–82 (2004).
    [Crossref]
  13. M. Mirhabibi, A. Negarestani, M. Agha Bolorizadeh, and M. Reza Rezaie, “A new approach for radon monitoring in soil as an earthquake precursor using optical fiber,” J. Radioanal. Nucl. Chem. 301(1), 207–211 (2014).
    [Crossref]
  14. D. Guimarães, C. S. Monteiro, Luis Peralta, and S. M. Barbosa, “Fiber optic sensor for radon monitoring: proof of concept,” RAD 2018 conference proceeding (2018).
  15. C. S. Monteiro, L. Coelho, S. M. Barbosa, and D. Guimarães, “Development of a New System for Real-Time Detection of Radon Using Scintillating Optical Fibers,” in 26th International Conference on Optical Fiber Sensors, OSA Technical Digest (Optical Society of America, 2018), paper WD5.
  16. B. K. Rejah, “Natural Occurring Radioactive Materials (NORM) and Technologically Enhanced NORM (TENORM) Measurements on Oil Field in North Region of Iraq,” PhD thesis (2015). https://www.researchgate.net/publication/307639330_Natural_Occurring_Radioactive_Materials_NORM_and_Tech nologically_Enhanced_NORM_TENORM_Measurements_on_Oil_Field_in_North_Region_of_Iraq#fullTextFile Content
  17. E. J. Friebele, K. J. Long, C. G. Askina, M. E. Gingerich, M. J. Marrone, and D. L. Griacom, “Overview of Radiation Effects In Fiber Optics,” In SPIE Proc. Vol. 0541, 70–88.(1985).
  18. B. Zmazek, L. Todorovski, S. Dzeroski, J. Vaupotic, and I. Kobal, “Application of Decision Trees to the Analysis of Soil Radon Data for Earthquake Prediction,” Appl. Radiat. Isot. 58(6), 697–706 (2003)..
    [Crossref]
  19. M. Namvaran and A. Negarestani, “Measuring the Radon Concentration and Investigating the Mechanism of Decline Prior an Earthquake,” J. Radioanal. Nucl. Chem. 298(1), 1–8 (2013).
    [Crossref]
  20. N. Akchurin, E. Kendir, S. Yaltkaya, J. Damgov, F. De Guio, and S. Kunori, “Radiation-hardness studies with cerium-doped fused-silica fibers,” J. Instrum. 14(03), P03020 (2019).
    [Crossref]
  21. A. El-Taher, “An overview of Instrumentation of Measuring Radon in Environmental Studies,” J. Rad. Nucl. Appl. 3(3), 135–141 (2018).
    [Crossref]
  22. M. Tirmarche, J. Harrison, D. Laurier, E. Blanchardon, F. Paquet, and J. Marsh, “Risk of Lung Cancer from Radon Exposure: Contribution of Recently Published Studies of Uranium Miners,” Ann. ICRP 41(3-4), 368–377 (2012).
    [Crossref]
  23. M. J. Buckler and M. R. Santana, “The Effect of Temperature on Fiber Loss And Pulse Delay Distortion For An Exploratory Fiber Optic Cable,” Optical Fiber Transmission II Technical Digest, (Optical Society of America, 1977), paper WA2.
  24. W. J. Goodman, E. A. Bahaa Saleh, and M. C. Teich, “Fundamentals of photonics,” 2nd edition, Wiley (2007).

2020 (1)

H. Zafrir, S. Barbosa, E. Levintal, N. Weisbrod, Y. Ben Horin, and Z. Zalevsky, “The Impact of Atmospheric and Tectonic Constraints on Radon-222 and Carbon Dioxide Flow in Geological Porous Media - A Dozen-Year Research Summary,” Frontiers in Earth Science 30, 433 (2020).
[Crossref]

2019 (1)

N. Akchurin, E. Kendir, S. Yaltkaya, J. Damgov, F. De Guio, and S. Kunori, “Radiation-hardness studies with cerium-doped fused-silica fibers,” J. Instrum. 14(03), P03020 (2019).
[Crossref]

2018 (1)

A. El-Taher, “An overview of Instrumentation of Measuring Radon in Environmental Studies,” J. Rad. Nucl. Appl. 3(3), 135–141 (2018).
[Crossref]

2016 (2)

A. Deb, M. Gazi, and C. Barman, “Anomalous Soil Radon Fluctuations – Signal of Earthquakes in Nepal and Eastern India Region’s,” J. Earth Syst. Sci. 125(1), 1–11 (2016).
[Crossref]

H. Zafrir, Y. Ben Horin, U. Malik, C. Chemo, and Z. Zalevsky, “Novel Determination of Radon-222 Velocity in Deep Subsurface Rocks, and the Feasibility to Using Radon as an Earthquake Precursor: Radon-222 Velocity in Deep Subsurface,” J. Geophys. Res. Solid Earth 121(9), 6346–6364 (2016).
[Crossref]

2015 (1)

A. da Rocha Lino, C. M. Abrahão, M. P. F. Amarante, and M. Rocha de Sousa Cruz, “The Role of the Implementation of Policies for the Prevention of Exposure to Radon in Brazil—a Strategy for Controlling the Risk of Developing Lung Cancer,” Ecancer 9, 572 (2015).
[Crossref]

2014 (1)

M. Mirhabibi, A. Negarestani, M. Agha Bolorizadeh, and M. Reza Rezaie, “A new approach for radon monitoring in soil as an earthquake precursor using optical fiber,” J. Radioanal. Nucl. Chem. 301(1), 207–211 (2014).
[Crossref]

2013 (1)

M. Namvaran and A. Negarestani, “Measuring the Radon Concentration and Investigating the Mechanism of Decline Prior an Earthquake,” J. Radioanal. Nucl. Chem. 298(1), 1–8 (2013).
[Crossref]

2012 (1)

M. Tirmarche, J. Harrison, D. Laurier, E. Blanchardon, F. Paquet, and J. Marsh, “Risk of Lung Cancer from Radon Exposure: Contribution of Recently Published Studies of Uranium Miners,” Ann. ICRP 41(3-4), 368–377 (2012).
[Crossref]

2010 (1)

F. Mireles, J. I. Dávila, M. L. García, J. L. Pinedo, and H. López, “Evaluation of Efficiency Calibration Parameters of the LR-115 Radon Detector,” Health Phys. 98(2), S63–S68 (2010).
[Crossref]

2008 (1)

S. Otto Wolfbeis, “Fiber-Optic Chemical Sensors and Biosensors,” Anal. Chem. 80(12), 4269–4283 (2008).
[Crossref]

2004 (1)

R. D. Evans and G. F. Knoll, “Remote optical detection of alpha particle sources,” Journal of Radiological Protection 24(1), 75–82 (2004).
[Crossref]

2003 (2)

B. Zmazek, L. Todorovski, S. Dzeroski, J. Vaupotic, and I. Kobal, “Application of Decision Trees to the Analysis of Soil Radon Data for Earthquake Prediction,” Appl. Radiat. Isot. 58(6), 697–706 (2003)..
[Crossref]

A. Negarestani, S. Setayeshi, M. Ghannadi-Maragheh, and B. Akashe, “Estimation of the Radon Concentration in Soil Related to the Environmental Parameters by a Modified Adaline Neural Network,” Appl. Radiat. Isot. 58(2), 269–273 (2003).
[Crossref]

2000 (1)

R. W. Field, D. J. Steck, B. J. Smith, C. P. Brus, E. L. Fisher, J. S. Neuberger, C. E. Platz, R. A. Robinson, R. F. Woolson, and C. F. Lynch, “Residential Radon Gas Exposure and Lung Cancer: The Iowa Radon Lung Cancer Study,” Am. J. Epidemiol. 151(11), 1091–1102 (2000).
[Crossref]

1978 (1)

R. L. Fleischer and A. Mogro-Campero, “Mapping of Integrated Radon Emanation for Detection of Long-Distance Migration of Gases within the Earth: Techniques and Principle,” J. Geophys. Res. Solid Earth 83(B7), 3539–3549 (1978).
[Crossref]

Abrahão, C. M.

A. da Rocha Lino, C. M. Abrahão, M. P. F. Amarante, and M. Rocha de Sousa Cruz, “The Role of the Implementation of Policies for the Prevention of Exposure to Radon in Brazil—a Strategy for Controlling the Risk of Developing Lung Cancer,” Ecancer 9, 572 (2015).
[Crossref]

Agha Bolorizadeh, M.

M. Mirhabibi, A. Negarestani, M. Agha Bolorizadeh, and M. Reza Rezaie, “A new approach for radon monitoring in soil as an earthquake precursor using optical fiber,” J. Radioanal. Nucl. Chem. 301(1), 207–211 (2014).
[Crossref]

Akashe, B.

A. Negarestani, S. Setayeshi, M. Ghannadi-Maragheh, and B. Akashe, “Estimation of the Radon Concentration in Soil Related to the Environmental Parameters by a Modified Adaline Neural Network,” Appl. Radiat. Isot. 58(2), 269–273 (2003).
[Crossref]

Akchurin, N.

N. Akchurin, E. Kendir, S. Yaltkaya, J. Damgov, F. De Guio, and S. Kunori, “Radiation-hardness studies with cerium-doped fused-silica fibers,” J. Instrum. 14(03), P03020 (2019).
[Crossref]

Amarante, M. P. F.

A. da Rocha Lino, C. M. Abrahão, M. P. F. Amarante, and M. Rocha de Sousa Cruz, “The Role of the Implementation of Policies for the Prevention of Exposure to Radon in Brazil—a Strategy for Controlling the Risk of Developing Lung Cancer,” Ecancer 9, 572 (2015).
[Crossref]

Askina, C. G.

E. J. Friebele, K. J. Long, C. G. Askina, M. E. Gingerich, M. J. Marrone, and D. L. Griacom, “Overview of Radiation Effects In Fiber Optics,” In SPIE Proc. Vol. 0541, 70–88.(1985).

Bahaa Saleh, E. A.

W. J. Goodman, E. A. Bahaa Saleh, and M. C. Teich, “Fundamentals of photonics,” 2nd edition, Wiley (2007).

Barbosa, S.

H. Zafrir, S. Barbosa, E. Levintal, N. Weisbrod, Y. Ben Horin, and Z. Zalevsky, “The Impact of Atmospheric and Tectonic Constraints on Radon-222 and Carbon Dioxide Flow in Geological Porous Media - A Dozen-Year Research Summary,” Frontiers in Earth Science 30, 433 (2020).
[Crossref]

Barbosa, S. M.

D. Guimarães, C. S. Monteiro, Luis Peralta, and S. M. Barbosa, “Fiber optic sensor for radon monitoring: proof of concept,” RAD 2018 conference proceeding (2018).

C. S. Monteiro, L. Coelho, S. M. Barbosa, and D. Guimarães, “Development of a New System for Real-Time Detection of Radon Using Scintillating Optical Fibers,” in 26th International Conference on Optical Fiber Sensors, OSA Technical Digest (Optical Society of America, 2018), paper WD5.

Barman, C.

A. Deb, M. Gazi, and C. Barman, “Anomalous Soil Radon Fluctuations – Signal of Earthquakes in Nepal and Eastern India Region’s,” J. Earth Syst. Sci. 125(1), 1–11 (2016).
[Crossref]

Ben Horin, Y.

H. Zafrir, S. Barbosa, E. Levintal, N. Weisbrod, Y. Ben Horin, and Z. Zalevsky, “The Impact of Atmospheric and Tectonic Constraints on Radon-222 and Carbon Dioxide Flow in Geological Porous Media - A Dozen-Year Research Summary,” Frontiers in Earth Science 30, 433 (2020).
[Crossref]

H. Zafrir, Y. Ben Horin, U. Malik, C. Chemo, and Z. Zalevsky, “Novel Determination of Radon-222 Velocity in Deep Subsurface Rocks, and the Feasibility to Using Radon as an Earthquake Precursor: Radon-222 Velocity in Deep Subsurface,” J. Geophys. Res. Solid Earth 121(9), 6346–6364 (2016).
[Crossref]

Blanchardon, E.

M. Tirmarche, J. Harrison, D. Laurier, E. Blanchardon, F. Paquet, and J. Marsh, “Risk of Lung Cancer from Radon Exposure: Contribution of Recently Published Studies of Uranium Miners,” Ann. ICRP 41(3-4), 368–377 (2012).
[Crossref]

Brus, C. P.

R. W. Field, D. J. Steck, B. J. Smith, C. P. Brus, E. L. Fisher, J. S. Neuberger, C. E. Platz, R. A. Robinson, R. F. Woolson, and C. F. Lynch, “Residential Radon Gas Exposure and Lung Cancer: The Iowa Radon Lung Cancer Study,” Am. J. Epidemiol. 151(11), 1091–1102 (2000).
[Crossref]

Buckler, M. J.

M. J. Buckler and M. R. Santana, “The Effect of Temperature on Fiber Loss And Pulse Delay Distortion For An Exploratory Fiber Optic Cable,” Optical Fiber Transmission II Technical Digest, (Optical Society of America, 1977), paper WA2.

Chemo, C.

H. Zafrir, Y. Ben Horin, U. Malik, C. Chemo, and Z. Zalevsky, “Novel Determination of Radon-222 Velocity in Deep Subsurface Rocks, and the Feasibility to Using Radon as an Earthquake Precursor: Radon-222 Velocity in Deep Subsurface,” J. Geophys. Res. Solid Earth 121(9), 6346–6364 (2016).
[Crossref]

Coelho, L.

C. S. Monteiro, L. Coelho, S. M. Barbosa, and D. Guimarães, “Development of a New System for Real-Time Detection of Radon Using Scintillating Optical Fibers,” in 26th International Conference on Optical Fiber Sensors, OSA Technical Digest (Optical Society of America, 2018), paper WD5.

da Rocha Lino, A.

A. da Rocha Lino, C. M. Abrahão, M. P. F. Amarante, and M. Rocha de Sousa Cruz, “The Role of the Implementation of Policies for the Prevention of Exposure to Radon in Brazil—a Strategy for Controlling the Risk of Developing Lung Cancer,” Ecancer 9, 572 (2015).
[Crossref]

Damgov, J.

N. Akchurin, E. Kendir, S. Yaltkaya, J. Damgov, F. De Guio, and S. Kunori, “Radiation-hardness studies with cerium-doped fused-silica fibers,” J. Instrum. 14(03), P03020 (2019).
[Crossref]

Dávila, J. I.

F. Mireles, J. I. Dávila, M. L. García, J. L. Pinedo, and H. López, “Evaluation of Efficiency Calibration Parameters of the LR-115 Radon Detector,” Health Phys. 98(2), S63–S68 (2010).
[Crossref]

De Guio, F.

N. Akchurin, E. Kendir, S. Yaltkaya, J. Damgov, F. De Guio, and S. Kunori, “Radiation-hardness studies with cerium-doped fused-silica fibers,” J. Instrum. 14(03), P03020 (2019).
[Crossref]

Deb, A.

A. Deb, M. Gazi, and C. Barman, “Anomalous Soil Radon Fluctuations – Signal of Earthquakes in Nepal and Eastern India Region’s,” J. Earth Syst. Sci. 125(1), 1–11 (2016).
[Crossref]

Dzeroski, S.

B. Zmazek, L. Todorovski, S. Dzeroski, J. Vaupotic, and I. Kobal, “Application of Decision Trees to the Analysis of Soil Radon Data for Earthquake Prediction,” Appl. Radiat. Isot. 58(6), 697–706 (2003)..
[Crossref]

El-Taher, A.

A. El-Taher, “An overview of Instrumentation of Measuring Radon in Environmental Studies,” J. Rad. Nucl. Appl. 3(3), 135–141 (2018).
[Crossref]

Evans, R. D.

R. D. Evans and G. F. Knoll, “Remote optical detection of alpha particle sources,” Journal of Radiological Protection 24(1), 75–82 (2004).
[Crossref]

Field, R. W.

R. W. Field, D. J. Steck, B. J. Smith, C. P. Brus, E. L. Fisher, J. S. Neuberger, C. E. Platz, R. A. Robinson, R. F. Woolson, and C. F. Lynch, “Residential Radon Gas Exposure and Lung Cancer: The Iowa Radon Lung Cancer Study,” Am. J. Epidemiol. 151(11), 1091–1102 (2000).
[Crossref]

Fisher, E. L.

R. W. Field, D. J. Steck, B. J. Smith, C. P. Brus, E. L. Fisher, J. S. Neuberger, C. E. Platz, R. A. Robinson, R. F. Woolson, and C. F. Lynch, “Residential Radon Gas Exposure and Lung Cancer: The Iowa Radon Lung Cancer Study,” Am. J. Epidemiol. 151(11), 1091–1102 (2000).
[Crossref]

Fleischer, R. L.

R. L. Fleischer and A. Mogro-Campero, “Mapping of Integrated Radon Emanation for Detection of Long-Distance Migration of Gases within the Earth: Techniques and Principle,” J. Geophys. Res. Solid Earth 83(B7), 3539–3549 (1978).
[Crossref]

Friebele, E. J.

E. J. Friebele, K. J. Long, C. G. Askina, M. E. Gingerich, M. J. Marrone, and D. L. Griacom, “Overview of Radiation Effects In Fiber Optics,” In SPIE Proc. Vol. 0541, 70–88.(1985).

García, M. L.

F. Mireles, J. I. Dávila, M. L. García, J. L. Pinedo, and H. López, “Evaluation of Efficiency Calibration Parameters of the LR-115 Radon Detector,” Health Phys. 98(2), S63–S68 (2010).
[Crossref]

Gazi, M.

A. Deb, M. Gazi, and C. Barman, “Anomalous Soil Radon Fluctuations – Signal of Earthquakes in Nepal and Eastern India Region’s,” J. Earth Syst. Sci. 125(1), 1–11 (2016).
[Crossref]

Ghannadi-Maragheh, M.

A. Negarestani, S. Setayeshi, M. Ghannadi-Maragheh, and B. Akashe, “Estimation of the Radon Concentration in Soil Related to the Environmental Parameters by a Modified Adaline Neural Network,” Appl. Radiat. Isot. 58(2), 269–273 (2003).
[Crossref]

Gingerich, M. E.

E. J. Friebele, K. J. Long, C. G. Askina, M. E. Gingerich, M. J. Marrone, and D. L. Griacom, “Overview of Radiation Effects In Fiber Optics,” In SPIE Proc. Vol. 0541, 70–88.(1985).

Goodman, W. J.

W. J. Goodman, E. A. Bahaa Saleh, and M. C. Teich, “Fundamentals of photonics,” 2nd edition, Wiley (2007).

Griacom, D. L.

E. J. Friebele, K. J. Long, C. G. Askina, M. E. Gingerich, M. J. Marrone, and D. L. Griacom, “Overview of Radiation Effects In Fiber Optics,” In SPIE Proc. Vol. 0541, 70–88.(1985).

Guimarães, D.

C. S. Monteiro, L. Coelho, S. M. Barbosa, and D. Guimarães, “Development of a New System for Real-Time Detection of Radon Using Scintillating Optical Fibers,” in 26th International Conference on Optical Fiber Sensors, OSA Technical Digest (Optical Society of America, 2018), paper WD5.

D. Guimarães, C. S. Monteiro, Luis Peralta, and S. M. Barbosa, “Fiber optic sensor for radon monitoring: proof of concept,” RAD 2018 conference proceeding (2018).

Harrison, J.

M. Tirmarche, J. Harrison, D. Laurier, E. Blanchardon, F. Paquet, and J. Marsh, “Risk of Lung Cancer from Radon Exposure: Contribution of Recently Published Studies of Uranium Miners,” Ann. ICRP 41(3-4), 368–377 (2012).
[Crossref]

Kendir, E.

N. Akchurin, E. Kendir, S. Yaltkaya, J. Damgov, F. De Guio, and S. Kunori, “Radiation-hardness studies with cerium-doped fused-silica fibers,” J. Instrum. 14(03), P03020 (2019).
[Crossref]

Knoll, G. F.

R. D. Evans and G. F. Knoll, “Remote optical detection of alpha particle sources,” Journal of Radiological Protection 24(1), 75–82 (2004).
[Crossref]

Kobal, I.

B. Zmazek, L. Todorovski, S. Dzeroski, J. Vaupotic, and I. Kobal, “Application of Decision Trees to the Analysis of Soil Radon Data for Earthquake Prediction,” Appl. Radiat. Isot. 58(6), 697–706 (2003)..
[Crossref]

Kunori, S.

N. Akchurin, E. Kendir, S. Yaltkaya, J. Damgov, F. De Guio, and S. Kunori, “Radiation-hardness studies with cerium-doped fused-silica fibers,” J. Instrum. 14(03), P03020 (2019).
[Crossref]

Laurier, D.

M. Tirmarche, J. Harrison, D. Laurier, E. Blanchardon, F. Paquet, and J. Marsh, “Risk of Lung Cancer from Radon Exposure: Contribution of Recently Published Studies of Uranium Miners,” Ann. ICRP 41(3-4), 368–377 (2012).
[Crossref]

Levintal, E.

H. Zafrir, S. Barbosa, E. Levintal, N. Weisbrod, Y. Ben Horin, and Z. Zalevsky, “The Impact of Atmospheric and Tectonic Constraints on Radon-222 and Carbon Dioxide Flow in Geological Porous Media - A Dozen-Year Research Summary,” Frontiers in Earth Science 30, 433 (2020).
[Crossref]

Long, K. J.

E. J. Friebele, K. J. Long, C. G. Askina, M. E. Gingerich, M. J. Marrone, and D. L. Griacom, “Overview of Radiation Effects In Fiber Optics,” In SPIE Proc. Vol. 0541, 70–88.(1985).

López, H.

F. Mireles, J. I. Dávila, M. L. García, J. L. Pinedo, and H. López, “Evaluation of Efficiency Calibration Parameters of the LR-115 Radon Detector,” Health Phys. 98(2), S63–S68 (2010).
[Crossref]

Lynch, C. F.

R. W. Field, D. J. Steck, B. J. Smith, C. P. Brus, E. L. Fisher, J. S. Neuberger, C. E. Platz, R. A. Robinson, R. F. Woolson, and C. F. Lynch, “Residential Radon Gas Exposure and Lung Cancer: The Iowa Radon Lung Cancer Study,” Am. J. Epidemiol. 151(11), 1091–1102 (2000).
[Crossref]

Malik, U.

H. Zafrir, Y. Ben Horin, U. Malik, C. Chemo, and Z. Zalevsky, “Novel Determination of Radon-222 Velocity in Deep Subsurface Rocks, and the Feasibility to Using Radon as an Earthquake Precursor: Radon-222 Velocity in Deep Subsurface,” J. Geophys. Res. Solid Earth 121(9), 6346–6364 (2016).
[Crossref]

Marrone, M. J.

E. J. Friebele, K. J. Long, C. G. Askina, M. E. Gingerich, M. J. Marrone, and D. L. Griacom, “Overview of Radiation Effects In Fiber Optics,” In SPIE Proc. Vol. 0541, 70–88.(1985).

Marsh, J.

M. Tirmarche, J. Harrison, D. Laurier, E. Blanchardon, F. Paquet, and J. Marsh, “Risk of Lung Cancer from Radon Exposure: Contribution of Recently Published Studies of Uranium Miners,” Ann. ICRP 41(3-4), 368–377 (2012).
[Crossref]

Mireles, F.

F. Mireles, J. I. Dávila, M. L. García, J. L. Pinedo, and H. López, “Evaluation of Efficiency Calibration Parameters of the LR-115 Radon Detector,” Health Phys. 98(2), S63–S68 (2010).
[Crossref]

Mirhabibi, M.

M. Mirhabibi, A. Negarestani, M. Agha Bolorizadeh, and M. Reza Rezaie, “A new approach for radon monitoring in soil as an earthquake precursor using optical fiber,” J. Radioanal. Nucl. Chem. 301(1), 207–211 (2014).
[Crossref]

Mogro-Campero, A.

R. L. Fleischer and A. Mogro-Campero, “Mapping of Integrated Radon Emanation for Detection of Long-Distance Migration of Gases within the Earth: Techniques and Principle,” J. Geophys. Res. Solid Earth 83(B7), 3539–3549 (1978).
[Crossref]

Monteiro, C. S.

D. Guimarães, C. S. Monteiro, Luis Peralta, and S. M. Barbosa, “Fiber optic sensor for radon monitoring: proof of concept,” RAD 2018 conference proceeding (2018).

C. S. Monteiro, L. Coelho, S. M. Barbosa, and D. Guimarães, “Development of a New System for Real-Time Detection of Radon Using Scintillating Optical Fibers,” in 26th International Conference on Optical Fiber Sensors, OSA Technical Digest (Optical Society of America, 2018), paper WD5.

Namvaran, M.

M. Namvaran and A. Negarestani, “Measuring the Radon Concentration and Investigating the Mechanism of Decline Prior an Earthquake,” J. Radioanal. Nucl. Chem. 298(1), 1–8 (2013).
[Crossref]

Negarestani, A.

M. Mirhabibi, A. Negarestani, M. Agha Bolorizadeh, and M. Reza Rezaie, “A new approach for radon monitoring in soil as an earthquake precursor using optical fiber,” J. Radioanal. Nucl. Chem. 301(1), 207–211 (2014).
[Crossref]

M. Namvaran and A. Negarestani, “Measuring the Radon Concentration and Investigating the Mechanism of Decline Prior an Earthquake,” J. Radioanal. Nucl. Chem. 298(1), 1–8 (2013).
[Crossref]

A. Negarestani, S. Setayeshi, M. Ghannadi-Maragheh, and B. Akashe, “Estimation of the Radon Concentration in Soil Related to the Environmental Parameters by a Modified Adaline Neural Network,” Appl. Radiat. Isot. 58(2), 269–273 (2003).
[Crossref]

Neuberger, J. S.

R. W. Field, D. J. Steck, B. J. Smith, C. P. Brus, E. L. Fisher, J. S. Neuberger, C. E. Platz, R. A. Robinson, R. F. Woolson, and C. F. Lynch, “Residential Radon Gas Exposure and Lung Cancer: The Iowa Radon Lung Cancer Study,” Am. J. Epidemiol. 151(11), 1091–1102 (2000).
[Crossref]

Otto Wolfbeis, S.

S. Otto Wolfbeis, “Fiber-Optic Chemical Sensors and Biosensors,” Anal. Chem. 80(12), 4269–4283 (2008).
[Crossref]

Paquet, F.

M. Tirmarche, J. Harrison, D. Laurier, E. Blanchardon, F. Paquet, and J. Marsh, “Risk of Lung Cancer from Radon Exposure: Contribution of Recently Published Studies of Uranium Miners,” Ann. ICRP 41(3-4), 368–377 (2012).
[Crossref]

Peralta, Luis

D. Guimarães, C. S. Monteiro, Luis Peralta, and S. M. Barbosa, “Fiber optic sensor for radon monitoring: proof of concept,” RAD 2018 conference proceeding (2018).

Pinedo, J. L.

F. Mireles, J. I. Dávila, M. L. García, J. L. Pinedo, and H. López, “Evaluation of Efficiency Calibration Parameters of the LR-115 Radon Detector,” Health Phys. 98(2), S63–S68 (2010).
[Crossref]

Platz, C. E.

R. W. Field, D. J. Steck, B. J. Smith, C. P. Brus, E. L. Fisher, J. S. Neuberger, C. E. Platz, R. A. Robinson, R. F. Woolson, and C. F. Lynch, “Residential Radon Gas Exposure and Lung Cancer: The Iowa Radon Lung Cancer Study,” Am. J. Epidemiol. 151(11), 1091–1102 (2000).
[Crossref]

Rejah, B. K.

B. K. Rejah, “Natural Occurring Radioactive Materials (NORM) and Technologically Enhanced NORM (TENORM) Measurements on Oil Field in North Region of Iraq,” PhD thesis (2015). https://www.researchgate.net/publication/307639330_Natural_Occurring_Radioactive_Materials_NORM_and_Tech nologically_Enhanced_NORM_TENORM_Measurements_on_Oil_Field_in_North_Region_of_Iraq#fullTextFile Content

Reza Rezaie, M.

M. Mirhabibi, A. Negarestani, M. Agha Bolorizadeh, and M. Reza Rezaie, “A new approach for radon monitoring in soil as an earthquake precursor using optical fiber,” J. Radioanal. Nucl. Chem. 301(1), 207–211 (2014).
[Crossref]

Robinson, R. A.

R. W. Field, D. J. Steck, B. J. Smith, C. P. Brus, E. L. Fisher, J. S. Neuberger, C. E. Platz, R. A. Robinson, R. F. Woolson, and C. F. Lynch, “Residential Radon Gas Exposure and Lung Cancer: The Iowa Radon Lung Cancer Study,” Am. J. Epidemiol. 151(11), 1091–1102 (2000).
[Crossref]

Rocha de Sousa Cruz, M.

A. da Rocha Lino, C. M. Abrahão, M. P. F. Amarante, and M. Rocha de Sousa Cruz, “The Role of the Implementation of Policies for the Prevention of Exposure to Radon in Brazil—a Strategy for Controlling the Risk of Developing Lung Cancer,” Ecancer 9, 572 (2015).
[Crossref]

Santana, M. R.

M. J. Buckler and M. R. Santana, “The Effect of Temperature on Fiber Loss And Pulse Delay Distortion For An Exploratory Fiber Optic Cable,” Optical Fiber Transmission II Technical Digest, (Optical Society of America, 1977), paper WA2.

Setayeshi, S.

A. Negarestani, S. Setayeshi, M. Ghannadi-Maragheh, and B. Akashe, “Estimation of the Radon Concentration in Soil Related to the Environmental Parameters by a Modified Adaline Neural Network,” Appl. Radiat. Isot. 58(2), 269–273 (2003).
[Crossref]

Smith, B. J.

R. W. Field, D. J. Steck, B. J. Smith, C. P. Brus, E. L. Fisher, J. S. Neuberger, C. E. Platz, R. A. Robinson, R. F. Woolson, and C. F. Lynch, “Residential Radon Gas Exposure and Lung Cancer: The Iowa Radon Lung Cancer Study,” Am. J. Epidemiol. 151(11), 1091–1102 (2000).
[Crossref]

Steck, D. J.

R. W. Field, D. J. Steck, B. J. Smith, C. P. Brus, E. L. Fisher, J. S. Neuberger, C. E. Platz, R. A. Robinson, R. F. Woolson, and C. F. Lynch, “Residential Radon Gas Exposure and Lung Cancer: The Iowa Radon Lung Cancer Study,” Am. J. Epidemiol. 151(11), 1091–1102 (2000).
[Crossref]

Teich, M. C.

W. J. Goodman, E. A. Bahaa Saleh, and M. C. Teich, “Fundamentals of photonics,” 2nd edition, Wiley (2007).

Tirmarche, M.

M. Tirmarche, J. Harrison, D. Laurier, E. Blanchardon, F. Paquet, and J. Marsh, “Risk of Lung Cancer from Radon Exposure: Contribution of Recently Published Studies of Uranium Miners,” Ann. ICRP 41(3-4), 368–377 (2012).
[Crossref]

Todorovski, L.

B. Zmazek, L. Todorovski, S. Dzeroski, J. Vaupotic, and I. Kobal, “Application of Decision Trees to the Analysis of Soil Radon Data for Earthquake Prediction,” Appl. Radiat. Isot. 58(6), 697–706 (2003)..
[Crossref]

Vaupotic, J.

B. Zmazek, L. Todorovski, S. Dzeroski, J. Vaupotic, and I. Kobal, “Application of Decision Trees to the Analysis of Soil Radon Data for Earthquake Prediction,” Appl. Radiat. Isot. 58(6), 697–706 (2003)..
[Crossref]

Weisbrod, N.

H. Zafrir, S. Barbosa, E. Levintal, N. Weisbrod, Y. Ben Horin, and Z. Zalevsky, “The Impact of Atmospheric and Tectonic Constraints on Radon-222 and Carbon Dioxide Flow in Geological Porous Media - A Dozen-Year Research Summary,” Frontiers in Earth Science 30, 433 (2020).
[Crossref]

Woolson, R. F.

R. W. Field, D. J. Steck, B. J. Smith, C. P. Brus, E. L. Fisher, J. S. Neuberger, C. E. Platz, R. A. Robinson, R. F. Woolson, and C. F. Lynch, “Residential Radon Gas Exposure and Lung Cancer: The Iowa Radon Lung Cancer Study,” Am. J. Epidemiol. 151(11), 1091–1102 (2000).
[Crossref]

Yaltkaya, S.

N. Akchurin, E. Kendir, S. Yaltkaya, J. Damgov, F. De Guio, and S. Kunori, “Radiation-hardness studies with cerium-doped fused-silica fibers,” J. Instrum. 14(03), P03020 (2019).
[Crossref]

Zafrir, H.

H. Zafrir, S. Barbosa, E. Levintal, N. Weisbrod, Y. Ben Horin, and Z. Zalevsky, “The Impact of Atmospheric and Tectonic Constraints on Radon-222 and Carbon Dioxide Flow in Geological Porous Media - A Dozen-Year Research Summary,” Frontiers in Earth Science 30, 433 (2020).
[Crossref]

H. Zafrir, Y. Ben Horin, U. Malik, C. Chemo, and Z. Zalevsky, “Novel Determination of Radon-222 Velocity in Deep Subsurface Rocks, and the Feasibility to Using Radon as an Earthquake Precursor: Radon-222 Velocity in Deep Subsurface,” J. Geophys. Res. Solid Earth 121(9), 6346–6364 (2016).
[Crossref]

Zalevsky, Z.

H. Zafrir, S. Barbosa, E. Levintal, N. Weisbrod, Y. Ben Horin, and Z. Zalevsky, “The Impact of Atmospheric and Tectonic Constraints on Radon-222 and Carbon Dioxide Flow in Geological Porous Media - A Dozen-Year Research Summary,” Frontiers in Earth Science 30, 433 (2020).
[Crossref]

H. Zafrir, Y. Ben Horin, U. Malik, C. Chemo, and Z. Zalevsky, “Novel Determination of Radon-222 Velocity in Deep Subsurface Rocks, and the Feasibility to Using Radon as an Earthquake Precursor: Radon-222 Velocity in Deep Subsurface,” J. Geophys. Res. Solid Earth 121(9), 6346–6364 (2016).
[Crossref]

Zmazek, B.

B. Zmazek, L. Todorovski, S. Dzeroski, J. Vaupotic, and I. Kobal, “Application of Decision Trees to the Analysis of Soil Radon Data for Earthquake Prediction,” Appl. Radiat. Isot. 58(6), 697–706 (2003)..
[Crossref]

Am. J. Epidemiol. (1)

R. W. Field, D. J. Steck, B. J. Smith, C. P. Brus, E. L. Fisher, J. S. Neuberger, C. E. Platz, R. A. Robinson, R. F. Woolson, and C. F. Lynch, “Residential Radon Gas Exposure and Lung Cancer: The Iowa Radon Lung Cancer Study,” Am. J. Epidemiol. 151(11), 1091–1102 (2000).
[Crossref]

Anal. Chem. (1)

S. Otto Wolfbeis, “Fiber-Optic Chemical Sensors and Biosensors,” Anal. Chem. 80(12), 4269–4283 (2008).
[Crossref]

Ann. ICRP (1)

M. Tirmarche, J. Harrison, D. Laurier, E. Blanchardon, F. Paquet, and J. Marsh, “Risk of Lung Cancer from Radon Exposure: Contribution of Recently Published Studies of Uranium Miners,” Ann. ICRP 41(3-4), 368–377 (2012).
[Crossref]

Appl. Radiat. Isot. (2)

A. Negarestani, S. Setayeshi, M. Ghannadi-Maragheh, and B. Akashe, “Estimation of the Radon Concentration in Soil Related to the Environmental Parameters by a Modified Adaline Neural Network,” Appl. Radiat. Isot. 58(2), 269–273 (2003).
[Crossref]

B. Zmazek, L. Todorovski, S. Dzeroski, J. Vaupotic, and I. Kobal, “Application of Decision Trees to the Analysis of Soil Radon Data for Earthquake Prediction,” Appl. Radiat. Isot. 58(6), 697–706 (2003)..
[Crossref]

Ecancer (1)

A. da Rocha Lino, C. M. Abrahão, M. P. F. Amarante, and M. Rocha de Sousa Cruz, “The Role of the Implementation of Policies for the Prevention of Exposure to Radon in Brazil—a Strategy for Controlling the Risk of Developing Lung Cancer,” Ecancer 9, 572 (2015).
[Crossref]

Frontiers in Earth Science (1)

H. Zafrir, S. Barbosa, E. Levintal, N. Weisbrod, Y. Ben Horin, and Z. Zalevsky, “The Impact of Atmospheric and Tectonic Constraints on Radon-222 and Carbon Dioxide Flow in Geological Porous Media - A Dozen-Year Research Summary,” Frontiers in Earth Science 30, 433 (2020).
[Crossref]

Health Phys. (1)

F. Mireles, J. I. Dávila, M. L. García, J. L. Pinedo, and H. López, “Evaluation of Efficiency Calibration Parameters of the LR-115 Radon Detector,” Health Phys. 98(2), S63–S68 (2010).
[Crossref]

J. Earth Syst. Sci. (1)

A. Deb, M. Gazi, and C. Barman, “Anomalous Soil Radon Fluctuations – Signal of Earthquakes in Nepal and Eastern India Region’s,” J. Earth Syst. Sci. 125(1), 1–11 (2016).
[Crossref]

J. Geophys. Res. Solid Earth (2)

H. Zafrir, Y. Ben Horin, U. Malik, C. Chemo, and Z. Zalevsky, “Novel Determination of Radon-222 Velocity in Deep Subsurface Rocks, and the Feasibility to Using Radon as an Earthquake Precursor: Radon-222 Velocity in Deep Subsurface,” J. Geophys. Res. Solid Earth 121(9), 6346–6364 (2016).
[Crossref]

R. L. Fleischer and A. Mogro-Campero, “Mapping of Integrated Radon Emanation for Detection of Long-Distance Migration of Gases within the Earth: Techniques and Principle,” J. Geophys. Res. Solid Earth 83(B7), 3539–3549 (1978).
[Crossref]

J. Instrum. (1)

N. Akchurin, E. Kendir, S. Yaltkaya, J. Damgov, F. De Guio, and S. Kunori, “Radiation-hardness studies with cerium-doped fused-silica fibers,” J. Instrum. 14(03), P03020 (2019).
[Crossref]

J. Rad. Nucl. Appl. (1)

A. El-Taher, “An overview of Instrumentation of Measuring Radon in Environmental Studies,” J. Rad. Nucl. Appl. 3(3), 135–141 (2018).
[Crossref]

J. Radioanal. Nucl. Chem. (2)

M. Namvaran and A. Negarestani, “Measuring the Radon Concentration and Investigating the Mechanism of Decline Prior an Earthquake,” J. Radioanal. Nucl. Chem. 298(1), 1–8 (2013).
[Crossref]

M. Mirhabibi, A. Negarestani, M. Agha Bolorizadeh, and M. Reza Rezaie, “A new approach for radon monitoring in soil as an earthquake precursor using optical fiber,” J. Radioanal. Nucl. Chem. 301(1), 207–211 (2014).
[Crossref]

Journal of Radiological Protection (1)

R. D. Evans and G. F. Knoll, “Remote optical detection of alpha particle sources,” Journal of Radiological Protection 24(1), 75–82 (2004).
[Crossref]

Other (8)

D. Guimarães, C. S. Monteiro, Luis Peralta, and S. M. Barbosa, “Fiber optic sensor for radon monitoring: proof of concept,” RAD 2018 conference proceeding (2018).

C. S. Monteiro, L. Coelho, S. M. Barbosa, and D. Guimarães, “Development of a New System for Real-Time Detection of Radon Using Scintillating Optical Fibers,” in 26th International Conference on Optical Fiber Sensors, OSA Technical Digest (Optical Society of America, 2018), paper WD5.

B. K. Rejah, “Natural Occurring Radioactive Materials (NORM) and Technologically Enhanced NORM (TENORM) Measurements on Oil Field in North Region of Iraq,” PhD thesis (2015). https://www.researchgate.net/publication/307639330_Natural_Occurring_Radioactive_Materials_NORM_and_Tech nologically_Enhanced_NORM_TENORM_Measurements_on_Oil_Field_in_North_Region_of_Iraq#fullTextFile Content

E. J. Friebele, K. J. Long, C. G. Askina, M. E. Gingerich, M. J. Marrone, and D. L. Griacom, “Overview of Radiation Effects In Fiber Optics,” In SPIE Proc. Vol. 0541, 70–88.(1985).

IARC Monographs on the Evaluation of Carcinogenic Risks to Humans, “Man-made Mineral Fibres and Radon,” Vol. 43, IARC Working Group on the Evaluation of Carcinogenic Risks to Humans, Lyon (FR): International Agency for Research on Cancer (1988).

M. J. Buckler and M. R. Santana, “The Effect of Temperature on Fiber Loss And Pulse Delay Distortion For An Exploratory Fiber Optic Cable,” Optical Fiber Transmission II Technical Digest, (Optical Society of America, 1977), paper WA2.

W. J. Goodman, E. A. Bahaa Saleh, and M. C. Teich, “Fundamentals of photonics,” 2nd edition, Wiley (2007).

A Report of a Task Group of the International Commission on Radiological Protection, “Protection against Radon-222 at Home and at Work,” ICRP Publication 65. Ann. ICRP 23 (2) (1993).

Data availability

Data underlying the results presented in this paper are not publicly available at this time but may be obtained from the authors upon reasonable request.

Cited By

Optica participates in Crossref's Cited-By Linking service. Citing articles from Optica Publishing Group journals and other participating publishers are listed here.

Alert me when this article is cited.


Figures (11)

Fig. 1.
Fig. 1. Schematic description of the experimental system. a) A Sealed radon glovebox. b) Ra-226Cl2 (radium chloride) radioactive source of radon-222 that serves as a source of alpha particles. c) a fiber optic system exposed to the α-particles inside the sealed chamber. d) The α-particles flux in Bq/m3 as measured by the Alpha guard detector. e) Air diffuser for homogeneous dispersion of the radon gas in the chamber. f) and g) optical spectrometer and light source /monitoring devices.
Fig. 2.
Fig. 2. The plot is of activity versus time for the parent and daughter products in secular equilibrium between the radon gas and it’s first solid radioactive decay product (RDP).
Fig. 3.
Fig. 3. Schematic description of the exposed fiber.
Fig. 4.
Fig. 4. Schematic description of the system.
Fig. 5.
Fig. 5. The light intensity pulses Vs. time. In each test the first pulse is acquired together with its 4-5 rounds pulse. The grey part is coined A, B, C is the degradation due to the alpha particle damage in each resonator round.
Fig. 6.
Fig. 6. The attenuation percentages versus time in each pulse replica.
Fig. 7.
Fig. 7. Examining of best wavelength impact.
Fig. 8.
Fig. 8. Measurement of the radon build-up flux in Bq/m3 and versus temperature (Celsius) and pressure (Bar), within the experimental glovebox versus time.
Fig. 9.
Fig. 9. Measurement of the radon build-up flux in Bq/m3 and the humidity, within the experimental glovebox versus time.
Fig. 10.
Fig. 10. Measurement of the radon build-up flux in Bq/m3 and the reduction in the optical response within the optical fiber.
Fig. 11.
Fig. 11. Schematic sketch of the optical sensor.

Tables (1)

Tables Icon

Table 1. Calculated properties of the loss due to different Gamma degradation percent.

Equations (12)

Equations on this page are rendered with MathJax. Learn more.

d N d d t = λ P N 0 e λ P t λ d N d
γ H = 98 % l i g h t p a s s e s t h r o u g h t h e 98 % p a t h
γ L = 2 % l i g h t p a s s e s t h r o u g h t h e 2 % p a t h
A I = P γ L C l o s s
A 0 = A I γ H , A 0 s c o p e = A I γ L
A 1 = A 0 ( C l o s s γ H 2 C l o s s 2 D l o s s ( t ) C l o s s M R e f l e c t e d C l o s s D l o s s ( t ) C l o s s 2 γ H 2 C l o s s γ H 2 C l o s s M R e f l e c t e d C l o s s γ H )
A 1 s c o p e = A 0 ( C l o s s γ H 2 C l o s s 2 D l o s s ( t ) C l o s s M l o s s C l o s s D l o s s ( t ) C l o s s 2 γ H 2 C l o s s γ H 2 C l o s s M l o s s C l o s s γ H γ L C l o s s )
K p a s s = 1 K l o s s = γ H 7 C l o s s 10 M l o s s 2 γ L
L R = A 1 / A 0 = K l o s s D l o s s 2 ( t )
D r = D M A n T exp ( 6 m n T 6 m 14 n T )
T = 2 D e l a y C
F = π R 1 R .