UV Raman Excitation Profiles of Imidazole, Imidazolium, and Water

which the radial Lorentz force is insufficient to retard the radial diffusion of ions and electrons in the plasma. In addit ion to increasing analyte l ine-to-background intensi ty ratios, the hot ter plasma core associated with the unidirectional discharge should be useful in the analysis of refractory solid powder samples. Prel iminary studies t4 have indicated tha t the graphite vapor theta-pinch plasma may be useful for the direct analysis of solid powders. The principal problem associated with the present unidirectional discharge system is the limitation to operation at 6 kV or less. This si tuation should be corrected by the use of fast-recovery diodes. Alternatively, a discharge circuit based on a dis tr ibuted-element LC transmission line should be capable of producing unidirectional, nearly square-wave current pulses without the use of a diode shunt. A low-voltage prototype circuit has produced very encouraging results.