Abstract

Noncontact detection of the homemade explosive constituents urea nitrate, nitromethane and ammonium nitrate is achieved using photodissociation followed by laser-induced fluorescence (PD-LIF). Our technique utilizes a single ultraviolet laser pulse (~7 ns) to vaporize and photodissociate the condensed-phase materials, and then to detect the resulting vibrationally-excited NO fragments via laser-induced fluorescence. PD-LIF excitation and emission spectra indicate the creation of NO in vibrationally-excited states with significant rotational energy, useful for low-background detection of the parent compound. The results for homemade explosives are compared to one another and 2,6-dinitrotoluene, a component present in many military explosives.

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  1. T. Tamiri, R. Rozin, N. Lemberger, and J. Almog, “Urea nitrate, an exceptionally easy-to-make improvised explosive: studies towards trace characterization,” Anal. Bioanal. Chem. 395(2), 421–428 (2009).
    [CrossRef] [PubMed]
  2. K. Yaeger, in Trace Chemical Sensing of Explosives R. Woodfin, ed. (Wiley, NY, 2007) Chap. 3.
  3. D. S. Moore, “Instrumentation for trace detection of high explosives,” Rev. Sci. Instrum. 75(8), 2499–2512 (2004).
    [CrossRef]
  4. T. Arusi-Parpar, D. Heflinger, and R. Lavi, “Photodissociation followed by laser-induced fluorescence at atmospheric pressure and 24 degrees C: a unique scheme for remote detection of explosives,” Appl. Opt. 40(36), 6677–6681 (2001).
    [CrossRef]
  5. D. Helfinger, T. Arusi-Parpar, Y. Ron, and R. Lavi, “Application of a unique scheme for remote detection of explosives,” Opt. Commun. 204(1-6), 327–331 (2002).
    [CrossRef]
  6. C. M. Wynn, S. Palmacci, R. R. Kunz, K. Clow, and M. Rothschild, “Detection of condensed-phase explosives via laser-induced vaporization, photodissociation, and resonant excitation,” Appl. Opt. 47(31), 5767–5776 (2008).
    [CrossRef]
  7. J. Steinfeld and J. Wormhoudt, “Explosives detection: A challenge for physical chemistry,” Annu. Rev. Phys. Chem. 49(1), 203–232 (1998).
    [CrossRef]
  8. Y. Q. Guo, A. Bhattacharya, and E. R. Bernstein, “Photodissociation dynamics of nitromethane at 226 and 271 nm at both nanosecond and femtosecond time scales,” J. Phys. Chem. 113, 85 (2009).
    [CrossRef]
  9. J. Luque and D.R. Crosley, “LIFBASE: Database and Spectral Simulation Program,” SRI International Report MP 99–009 (1999).
  10. J. Luque and D. R. Crosley, “Transition probabilities and electronic transition moments of the A2Σ+–X2Π and D2Σ+–X2Π systems of nitric oxide,” J. Chem. Phys. 111, 7405 (1999).
    [CrossRef]
  11. P. Grammaticakis, “Contributiona l’etude de l’absorption dans l’ultraviolet moyen des anilines ortho-substituees. III. Orthonitro- et orthocarboxy- anilines N-substituees,” Bull. Soc. Chim. Fr. 17, 158–166 (1950).
  12. We assume the nitrate dominates the absorption near 236 nm. Nitrate cross section from:G. Mark, H. Korth, H. Schuchmann, and C. von Sonntag, “The photochemistry of aqueous nitrate ion revisited,” J. Photochem. Photobio. A 101(2-3), 89–103 (1996).
    [CrossRef]
  13. Y. Q. Guo, M. Greenfield, A. Bhattacharya, and E. R. Bernstein, “On the excited electronic state dissociation of nitramine energetic materials and model systems,” J. Chem. Phys. 127(15), 154301 (2007).
    [CrossRef] [PubMed]
  14. Y. Q. Guo, M. Greenfield, and E. R. Bernstein, “Decomposition of nitramine energetic materials in excited electronic states: RDX and HMX,” J. Chem. Phys. 122(24), 244310 (2005).
    [CrossRef] [PubMed]
  15. T. Tajime, T. Saheki, and K. Ito, “Absorption characteristics of the γ-0 band of nitric oxide,” Appl. Opt. 17(8), 1290–1294 (1978).
    [CrossRef] [PubMed]
  16. M. Islam, I. W. M. Smith, and M. H. Alexander, “Rate constants for total relaxation from the rotational levels J = 7.5, 20.5, 31.5 and 40.5 in NO(X2Π1/2, v = 2) in collisions with He, Ar and N2: a comparison between experiment and theory,” Chem. Phys. Lett. 305(5-6), 311–318 (1999).
    [CrossRef]
  17. C. M. Wynn, S. Palmacci, R. R. Kunz, J. J. Zayhowski, B. Edwards, and M. Rothschild, “Experimental demonstration of remote detection of trace explosives,” Proc. SPIE 6954, 695407 (2008).
    [CrossRef]

2009

Y. Q. Guo, A. Bhattacharya, and E. R. Bernstein, “Photodissociation dynamics of nitromethane at 226 and 271 nm at both nanosecond and femtosecond time scales,” J. Phys. Chem. 113, 85 (2009).
[CrossRef]

T. Tamiri, R. Rozin, N. Lemberger, and J. Almog, “Urea nitrate, an exceptionally easy-to-make improvised explosive: studies towards trace characterization,” Anal. Bioanal. Chem. 395(2), 421–428 (2009).
[CrossRef] [PubMed]

2008

C. M. Wynn, S. Palmacci, R. R. Kunz, J. J. Zayhowski, B. Edwards, and M. Rothschild, “Experimental demonstration of remote detection of trace explosives,” Proc. SPIE 6954, 695407 (2008).
[CrossRef]

C. M. Wynn, S. Palmacci, R. R. Kunz, K. Clow, and M. Rothschild, “Detection of condensed-phase explosives via laser-induced vaporization, photodissociation, and resonant excitation,” Appl. Opt. 47(31), 5767–5776 (2008).
[CrossRef]

2007

Y. Q. Guo, M. Greenfield, A. Bhattacharya, and E. R. Bernstein, “On the excited electronic state dissociation of nitramine energetic materials and model systems,” J. Chem. Phys. 127(15), 154301 (2007).
[CrossRef] [PubMed]

2005

Y. Q. Guo, M. Greenfield, and E. R. Bernstein, “Decomposition of nitramine energetic materials in excited electronic states: RDX and HMX,” J. Chem. Phys. 122(24), 244310 (2005).
[CrossRef] [PubMed]

2004

D. S. Moore, “Instrumentation for trace detection of high explosives,” Rev. Sci. Instrum. 75(8), 2499–2512 (2004).
[CrossRef]

2002

D. Helfinger, T. Arusi-Parpar, Y. Ron, and R. Lavi, “Application of a unique scheme for remote detection of explosives,” Opt. Commun. 204(1-6), 327–331 (2002).
[CrossRef]

2001

1999

M. Islam, I. W. M. Smith, and M. H. Alexander, “Rate constants for total relaxation from the rotational levels J = 7.5, 20.5, 31.5 and 40.5 in NO(X2Π1/2, v = 2) in collisions with He, Ar and N2: a comparison between experiment and theory,” Chem. Phys. Lett. 305(5-6), 311–318 (1999).
[CrossRef]

J. Luque and D. R. Crosley, “Transition probabilities and electronic transition moments of the A2Σ+–X2Π and D2Σ+–X2Π systems of nitric oxide,” J. Chem. Phys. 111, 7405 (1999).
[CrossRef]

1998

J. Steinfeld and J. Wormhoudt, “Explosives detection: A challenge for physical chemistry,” Annu. Rev. Phys. Chem. 49(1), 203–232 (1998).
[CrossRef]

1996

We assume the nitrate dominates the absorption near 236 nm. Nitrate cross section from:G. Mark, H. Korth, H. Schuchmann, and C. von Sonntag, “The photochemistry of aqueous nitrate ion revisited,” J. Photochem. Photobio. A 101(2-3), 89–103 (1996).
[CrossRef]

1978

1950

P. Grammaticakis, “Contributiona l’etude de l’absorption dans l’ultraviolet moyen des anilines ortho-substituees. III. Orthonitro- et orthocarboxy- anilines N-substituees,” Bull. Soc. Chim. Fr. 17, 158–166 (1950).

Alexander, M. H.

M. Islam, I. W. M. Smith, and M. H. Alexander, “Rate constants for total relaxation from the rotational levels J = 7.5, 20.5, 31.5 and 40.5 in NO(X2Π1/2, v = 2) in collisions with He, Ar and N2: a comparison between experiment and theory,” Chem. Phys. Lett. 305(5-6), 311–318 (1999).
[CrossRef]

Almog, J.

T. Tamiri, R. Rozin, N. Lemberger, and J. Almog, “Urea nitrate, an exceptionally easy-to-make improvised explosive: studies towards trace characterization,” Anal. Bioanal. Chem. 395(2), 421–428 (2009).
[CrossRef] [PubMed]

Arusi-Parpar, T.

Bernstein, E. R.

Y. Q. Guo, A. Bhattacharya, and E. R. Bernstein, “Photodissociation dynamics of nitromethane at 226 and 271 nm at both nanosecond and femtosecond time scales,” J. Phys. Chem. 113, 85 (2009).
[CrossRef]

Y. Q. Guo, M. Greenfield, A. Bhattacharya, and E. R. Bernstein, “On the excited electronic state dissociation of nitramine energetic materials and model systems,” J. Chem. Phys. 127(15), 154301 (2007).
[CrossRef] [PubMed]

Y. Q. Guo, M. Greenfield, and E. R. Bernstein, “Decomposition of nitramine energetic materials in excited electronic states: RDX and HMX,” J. Chem. Phys. 122(24), 244310 (2005).
[CrossRef] [PubMed]

Bhattacharya, A.

Y. Q. Guo, A. Bhattacharya, and E. R. Bernstein, “Photodissociation dynamics of nitromethane at 226 and 271 nm at both nanosecond and femtosecond time scales,” J. Phys. Chem. 113, 85 (2009).
[CrossRef]

Y. Q. Guo, M. Greenfield, A. Bhattacharya, and E. R. Bernstein, “On the excited electronic state dissociation of nitramine energetic materials and model systems,” J. Chem. Phys. 127(15), 154301 (2007).
[CrossRef] [PubMed]

Clow, K.

Crosley, D. R.

J. Luque and D. R. Crosley, “Transition probabilities and electronic transition moments of the A2Σ+–X2Π and D2Σ+–X2Π systems of nitric oxide,” J. Chem. Phys. 111, 7405 (1999).
[CrossRef]

Edwards, B.

C. M. Wynn, S. Palmacci, R. R. Kunz, J. J. Zayhowski, B. Edwards, and M. Rothschild, “Experimental demonstration of remote detection of trace explosives,” Proc. SPIE 6954, 695407 (2008).
[CrossRef]

Grammaticakis, P.

P. Grammaticakis, “Contributiona l’etude de l’absorption dans l’ultraviolet moyen des anilines ortho-substituees. III. Orthonitro- et orthocarboxy- anilines N-substituees,” Bull. Soc. Chim. Fr. 17, 158–166 (1950).

Greenfield, M.

Y. Q. Guo, M. Greenfield, A. Bhattacharya, and E. R. Bernstein, “On the excited electronic state dissociation of nitramine energetic materials and model systems,” J. Chem. Phys. 127(15), 154301 (2007).
[CrossRef] [PubMed]

Y. Q. Guo, M. Greenfield, and E. R. Bernstein, “Decomposition of nitramine energetic materials in excited electronic states: RDX and HMX,” J. Chem. Phys. 122(24), 244310 (2005).
[CrossRef] [PubMed]

Guo, Y. Q.

Y. Q. Guo, A. Bhattacharya, and E. R. Bernstein, “Photodissociation dynamics of nitromethane at 226 and 271 nm at both nanosecond and femtosecond time scales,” J. Phys. Chem. 113, 85 (2009).
[CrossRef]

Y. Q. Guo, M. Greenfield, A. Bhattacharya, and E. R. Bernstein, “On the excited electronic state dissociation of nitramine energetic materials and model systems,” J. Chem. Phys. 127(15), 154301 (2007).
[CrossRef] [PubMed]

Y. Q. Guo, M. Greenfield, and E. R. Bernstein, “Decomposition of nitramine energetic materials in excited electronic states: RDX and HMX,” J. Chem. Phys. 122(24), 244310 (2005).
[CrossRef] [PubMed]

Heflinger, D.

Helfinger, D.

D. Helfinger, T. Arusi-Parpar, Y. Ron, and R. Lavi, “Application of a unique scheme for remote detection of explosives,” Opt. Commun. 204(1-6), 327–331 (2002).
[CrossRef]

Islam, M.

M. Islam, I. W. M. Smith, and M. H. Alexander, “Rate constants for total relaxation from the rotational levels J = 7.5, 20.5, 31.5 and 40.5 in NO(X2Π1/2, v = 2) in collisions with He, Ar and N2: a comparison between experiment and theory,” Chem. Phys. Lett. 305(5-6), 311–318 (1999).
[CrossRef]

Ito, K.

Korth, H.

We assume the nitrate dominates the absorption near 236 nm. Nitrate cross section from:G. Mark, H. Korth, H. Schuchmann, and C. von Sonntag, “The photochemistry of aqueous nitrate ion revisited,” J. Photochem. Photobio. A 101(2-3), 89–103 (1996).
[CrossRef]

Kunz, R. R.

C. M. Wynn, S. Palmacci, R. R. Kunz, K. Clow, and M. Rothschild, “Detection of condensed-phase explosives via laser-induced vaporization, photodissociation, and resonant excitation,” Appl. Opt. 47(31), 5767–5776 (2008).
[CrossRef]

C. M. Wynn, S. Palmacci, R. R. Kunz, J. J. Zayhowski, B. Edwards, and M. Rothschild, “Experimental demonstration of remote detection of trace explosives,” Proc. SPIE 6954, 695407 (2008).
[CrossRef]

Lavi, R.

Lemberger, N.

T. Tamiri, R. Rozin, N. Lemberger, and J. Almog, “Urea nitrate, an exceptionally easy-to-make improvised explosive: studies towards trace characterization,” Anal. Bioanal. Chem. 395(2), 421–428 (2009).
[CrossRef] [PubMed]

Luque, J.

J. Luque and D. R. Crosley, “Transition probabilities and electronic transition moments of the A2Σ+–X2Π and D2Σ+–X2Π systems of nitric oxide,” J. Chem. Phys. 111, 7405 (1999).
[CrossRef]

Mark, G.

We assume the nitrate dominates the absorption near 236 nm. Nitrate cross section from:G. Mark, H. Korth, H. Schuchmann, and C. von Sonntag, “The photochemistry of aqueous nitrate ion revisited,” J. Photochem. Photobio. A 101(2-3), 89–103 (1996).
[CrossRef]

Moore, D. S.

D. S. Moore, “Instrumentation for trace detection of high explosives,” Rev. Sci. Instrum. 75(8), 2499–2512 (2004).
[CrossRef]

Palmacci, S.

C. M. Wynn, S. Palmacci, R. R. Kunz, J. J. Zayhowski, B. Edwards, and M. Rothschild, “Experimental demonstration of remote detection of trace explosives,” Proc. SPIE 6954, 695407 (2008).
[CrossRef]

C. M. Wynn, S. Palmacci, R. R. Kunz, K. Clow, and M. Rothschild, “Detection of condensed-phase explosives via laser-induced vaporization, photodissociation, and resonant excitation,” Appl. Opt. 47(31), 5767–5776 (2008).
[CrossRef]

Ron, Y.

D. Helfinger, T. Arusi-Parpar, Y. Ron, and R. Lavi, “Application of a unique scheme for remote detection of explosives,” Opt. Commun. 204(1-6), 327–331 (2002).
[CrossRef]

Rothschild, M.

C. M. Wynn, S. Palmacci, R. R. Kunz, K. Clow, and M. Rothschild, “Detection of condensed-phase explosives via laser-induced vaporization, photodissociation, and resonant excitation,” Appl. Opt. 47(31), 5767–5776 (2008).
[CrossRef]

C. M. Wynn, S. Palmacci, R. R. Kunz, J. J. Zayhowski, B. Edwards, and M. Rothschild, “Experimental demonstration of remote detection of trace explosives,” Proc. SPIE 6954, 695407 (2008).
[CrossRef]

Rozin, R.

T. Tamiri, R. Rozin, N. Lemberger, and J. Almog, “Urea nitrate, an exceptionally easy-to-make improvised explosive: studies towards trace characterization,” Anal. Bioanal. Chem. 395(2), 421–428 (2009).
[CrossRef] [PubMed]

Saheki, T.

Schuchmann, H.

We assume the nitrate dominates the absorption near 236 nm. Nitrate cross section from:G. Mark, H. Korth, H. Schuchmann, and C. von Sonntag, “The photochemistry of aqueous nitrate ion revisited,” J. Photochem. Photobio. A 101(2-3), 89–103 (1996).
[CrossRef]

Smith, I. W. M.

M. Islam, I. W. M. Smith, and M. H. Alexander, “Rate constants for total relaxation from the rotational levels J = 7.5, 20.5, 31.5 and 40.5 in NO(X2Π1/2, v = 2) in collisions with He, Ar and N2: a comparison between experiment and theory,” Chem. Phys. Lett. 305(5-6), 311–318 (1999).
[CrossRef]

Steinfeld, J.

J. Steinfeld and J. Wormhoudt, “Explosives detection: A challenge for physical chemistry,” Annu. Rev. Phys. Chem. 49(1), 203–232 (1998).
[CrossRef]

Tajime, T.

Tamiri, T.

T. Tamiri, R. Rozin, N. Lemberger, and J. Almog, “Urea nitrate, an exceptionally easy-to-make improvised explosive: studies towards trace characterization,” Anal. Bioanal. Chem. 395(2), 421–428 (2009).
[CrossRef] [PubMed]

von Sonntag, C.

We assume the nitrate dominates the absorption near 236 nm. Nitrate cross section from:G. Mark, H. Korth, H. Schuchmann, and C. von Sonntag, “The photochemistry of aqueous nitrate ion revisited,” J. Photochem. Photobio. A 101(2-3), 89–103 (1996).
[CrossRef]

Wormhoudt, J.

J. Steinfeld and J. Wormhoudt, “Explosives detection: A challenge for physical chemistry,” Annu. Rev. Phys. Chem. 49(1), 203–232 (1998).
[CrossRef]

Wynn, C. M.

C. M. Wynn, S. Palmacci, R. R. Kunz, K. Clow, and M. Rothschild, “Detection of condensed-phase explosives via laser-induced vaporization, photodissociation, and resonant excitation,” Appl. Opt. 47(31), 5767–5776 (2008).
[CrossRef]

C. M. Wynn, S. Palmacci, R. R. Kunz, J. J. Zayhowski, B. Edwards, and M. Rothschild, “Experimental demonstration of remote detection of trace explosives,” Proc. SPIE 6954, 695407 (2008).
[CrossRef]

Zayhowski, J. J.

C. M. Wynn, S. Palmacci, R. R. Kunz, J. J. Zayhowski, B. Edwards, and M. Rothschild, “Experimental demonstration of remote detection of trace explosives,” Proc. SPIE 6954, 695407 (2008).
[CrossRef]

Anal. Bioanal. Chem.

T. Tamiri, R. Rozin, N. Lemberger, and J. Almog, “Urea nitrate, an exceptionally easy-to-make improvised explosive: studies towards trace characterization,” Anal. Bioanal. Chem. 395(2), 421–428 (2009).
[CrossRef] [PubMed]

Annu. Rev. Phys. Chem.

J. Steinfeld and J. Wormhoudt, “Explosives detection: A challenge for physical chemistry,” Annu. Rev. Phys. Chem. 49(1), 203–232 (1998).
[CrossRef]

Appl. Opt.

Bull. Soc. Chim. Fr.

P. Grammaticakis, “Contributiona l’etude de l’absorption dans l’ultraviolet moyen des anilines ortho-substituees. III. Orthonitro- et orthocarboxy- anilines N-substituees,” Bull. Soc. Chim. Fr. 17, 158–166 (1950).

Chem. Phys. Lett.

M. Islam, I. W. M. Smith, and M. H. Alexander, “Rate constants for total relaxation from the rotational levels J = 7.5, 20.5, 31.5 and 40.5 in NO(X2Π1/2, v = 2) in collisions with He, Ar and N2: a comparison between experiment and theory,” Chem. Phys. Lett. 305(5-6), 311–318 (1999).
[CrossRef]

J. Chem. Phys.

J. Luque and D. R. Crosley, “Transition probabilities and electronic transition moments of the A2Σ+–X2Π and D2Σ+–X2Π systems of nitric oxide,” J. Chem. Phys. 111, 7405 (1999).
[CrossRef]

Y. Q. Guo, M. Greenfield, A. Bhattacharya, and E. R. Bernstein, “On the excited electronic state dissociation of nitramine energetic materials and model systems,” J. Chem. Phys. 127(15), 154301 (2007).
[CrossRef] [PubMed]

Y. Q. Guo, M. Greenfield, and E. R. Bernstein, “Decomposition of nitramine energetic materials in excited electronic states: RDX and HMX,” J. Chem. Phys. 122(24), 244310 (2005).
[CrossRef] [PubMed]

J. Photochem. Photobio. A

We assume the nitrate dominates the absorption near 236 nm. Nitrate cross section from:G. Mark, H. Korth, H. Schuchmann, and C. von Sonntag, “The photochemistry of aqueous nitrate ion revisited,” J. Photochem. Photobio. A 101(2-3), 89–103 (1996).
[CrossRef]

J. Phys. Chem.

Y. Q. Guo, A. Bhattacharya, and E. R. Bernstein, “Photodissociation dynamics of nitromethane at 226 and 271 nm at both nanosecond and femtosecond time scales,” J. Phys. Chem. 113, 85 (2009).
[CrossRef]

Opt. Commun.

D. Helfinger, T. Arusi-Parpar, Y. Ron, and R. Lavi, “Application of a unique scheme for remote detection of explosives,” Opt. Commun. 204(1-6), 327–331 (2002).
[CrossRef]

Proc. SPIE

C. M. Wynn, S. Palmacci, R. R. Kunz, J. J. Zayhowski, B. Edwards, and M. Rothschild, “Experimental demonstration of remote detection of trace explosives,” Proc. SPIE 6954, 695407 (2008).
[CrossRef]

Rev. Sci. Instrum.

D. S. Moore, “Instrumentation for trace detection of high explosives,” Rev. Sci. Instrum. 75(8), 2499–2512 (2004).
[CrossRef]

Other

J. Luque and D.R. Crosley, “LIFBASE: Database and Spectral Simulation Program,” SRI International Report MP 99–009 (1999).

K. Yaeger, in Trace Chemical Sensing of Explosives R. Woodfin, ed. (Wiley, NY, 2007) Chap. 3.

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Figures (4)

Fig. 1
Fig. 1

Photodissociated NO energy levels for the vaporization/PD-LIF detection process. NO fragments are optically excited from their vibrationally-excited electronic ground state to an electronically excited state. The blue-shifted fluorescence is used for detection. Several excitation-emission processes are shown.

Fig. 2
Fig. 2

PD-LIF excitation spectra: blue-shifted fluorescence as a function of excitation λ. Insets are close-ups of (v” = 1) excitation. Symbols are experimental data; lines are simulated NO fluorescence with the following parameters (and uncertainties): (a) NM: (v” = 1)→(v’ = 0), TRot = 1000 K ± 500 K (near 236 nm) ; (v” = 2)→(v’ = 0), TRot = 500 K ± 200 K (near 247 nm) ; (v” = 3)→(v’ = 1), TRot = 1000 K ± 500 K (near 243 nm); (b) UN: (v” = 1)→(v’ = 0), TRot = 300 K ± 100 K; (c) AN: (v” = 1)→(v’ = 0), TRot = 1000 K ± 500 K; (v” = 2)→(v’ = 0), TRot = 1000 K ± 500 K; (d) DNT: (v” = 1)→(v’ = 0), TRot = 1000 K ± 500 K; (v” = 2)→(v’ = 0), TRot = 2000 K ± 700 K.

Fig. 3
Fig. 3

PD-LIF emission spectra for various HMEs and DNT. Symbols are experimental data. Spectral resolution was 0.53 nm, except for 236 nm excitation of NM (0.25 nm) and 243 nm excitation of UN (0.25 nm) and DNT (0.74 nm). NM data in a) have been offset for clarity. Lines are simulated NO emission with TRot = 350 K. In a) lines correspond to (v’ = 0)→(v” = 0) transition; in b) lines correspond to (v’ = 1)→(v” = 0,1) transitions.

Fig. 4
Fig. 4

Comparison of PD-LIF signal strengths for various explosives. Data are derived from excitation spectra at 10 mJ/cm2 fluence. HMEs are noted in red.

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