Harilal, S S; Issac, Riju C; Bindhu, C V; Pramod, Gopinath; Nampoori, V P N; Vallabhan, C P G(Elsevier, 1997)
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Abstract:
Time and space resolved studies of emission from CN molecules have been carried out in the plasma produced from
graphite target by 1.06 urn pulses from a Q-switched Nd:YAG laser. Depending on the laser pulse energy, time of
observation and position of the sampled volume of the plasma, the features of the emission spectrum are found to
change drastically. The vibrational temperature and population distribution in the different vibrational levels have
been studied as functions of distance, time, laser energy and ambient gas pressure. Evidence for nonlinear effects of
the plasma medium such as self focusing which exhibits threshold-like behaviour are also obtained. Temperature and
electron density of the plasma have been evaluated using the relative line intensities of successive ionization stages of
carbon atom. These electron density measurements are verified by using Stark broadening method.