Abstract
The technique of femtosecond laser-induced breakdown spectroscopy (FLIBS) was
employed to investigate seven explosive molecules of nitropyrazole in three
different atmospheres: ambient air, nitrogen, and argon. The FLIBS data illustrated
the presence of molecular emissions of cyanide (CN) violet bands, diatomic carbon
(C2) Swan bands, and atomic emission lines of C, H, O, and N. To
understand the plasma dynamics, the decay times of molecular and atomic emissions
were determined from time-resolved spectral data obtained in three atmospheres: air,
argon, and nitrogen. The CN decay time was observed to be longest in air, compared
to nitrogen and argon atmospheres, for the molecules pyrazole (PY) and
4-nitropyrazole (4-NPY). In the case of C2 emission, the decay time was
observed to be the longest in argon, compared to the air and nitrogen environments,
for the molecules PY, 4-NPY, and 1-methyl-3,4,5-trinitropyrazole. The intensities of
the CN, C2, C, H, O, and N emission lines and various molecular/atomic
intensity ratios such as CN/C2,
CNsum/C2sum, CN/C, CNsum/C,
C2/C, C2sum/C, (C2 + C) / CN,
(C2sum + C)/CNsum, O/H, O/N, and N/H were also
deduced from the LIBS spectra obtained in argon atmosphere. A correlation between
the observed decay times and molecular emission intensities with respect to the
number of nitro groups, the atmospheric nitrogen content, and the oxygen balance of
the molecules was investigated. The relationship among the LIBS signal intensity,
the molecular/atomic intensity ratios, and the oxygen balance of these organic
explosives was also explored.
PDF Article
More Like This
Cited By
You do not have subscription access to this journal. Cited by links are available to subscribers only. You may subscribe either as an Optica member, or as an authorized user of your institution.
Contact your librarian or system administrator
or
Login to access Optica Member Subscription
Add to BibSonomy