Experimental and theoretical investigations of a XeCl phototriggered laser

Abstract

Detailed experimental and theoretical studies of a phototriggered XeCl excimer laser have been performed through the development and the experimental validation of a zero-dimensional model, which self-consistently coupled the solution of the Boltzmann equation, the kinetic equations of heavy particles, the electrical circuit and the photon equations. A detailed description of the XeCl molecule and of the associated kinetics has been taken into account, together with the effect of the gas temperature growth on the stimulated emission cross section. The model predictions have been compared with the experimental results obtained from a complete set of time-resolved electrical and optical diagnostics including emission and laser absorption spectroscopy on various xenon and neon states. A specific output energy of 7.6 J l-1 and an efficiency of 3.5% are reported, which indicates the effectiveness of the phototriggered discharges to produce high-performance excimer lasers. Simple rules allowing the calculation of the required voltage for best efficiency or maximum output laser energy are given.

Theoretical study of the pre-ionized XeCl laser

“…In order to verify the validity of our computations, in Fig. 5 we present the discharge current obtained by our model and the measurements of Riva et al [13] for the initial reduced electric field E/N 0 = 14.1 Td. The impulse of current has the same form and the current calculated by our model is always slightly lower than that of the experiment with the same rise time and impulse duration.…”

“…Comparison of the discharge current between measurements of Riva et al[13] and our calculations for the following conditions: gas mixture composition Ne(99.33%)-Xe(0.5%)-HCl(0.17%), C = 144 nF, L = 3.3 nH, P = 4 bar, electrode area 50 cm 2 , gap distance of 1 cm, and E/N 0 = 14.1 Td.…”

LIF spectroscopy applied to the study of non-thermal plasmas for atmospheric pollutant abatement

“…Formerly designed for the development of high-power lasers [25,26], the photo-triggering technique has been more recently applied to gas mixtures (N 2 /O 2 /H 2 O) relevant for atmospheric pollutant removal, such as NO [27] or light olefins [28]. We have undertaken, for a few years, basic research on the high-pressure non-thermal plasma chemistry using time resolved LIF diagnostic coupled to photo-triggered discharge.…”

“…A comprehensive description of the photo-triggered discharge operating mode has been previously described in detail [20,[25][26][27] and only a brief description of our device is given here. Two electrodes, 50 cm long with a spacing d = 1 cm and a flat profile over 1 cm width, are directly connected to an energy storage unit of capacitance C = 17.44 nF charged up to a voltage V 0 in a few hundred nanoseconds.…”

Fundamentals and Current Status of Excimer Lasers

“…In a discharge excited rare gas halide laser, a great number of reactions are possible and seem to play an important role in the kinetics of the discharge and of the populations. Table 4 lists the reactions and reaction rates proposed by Riva [20] for a so called "simplified model". With more than 100 reactions, a physical understanding of the discharge is not straightforward.…”