The generalised oscillator strength formalism is used to calculate a complete and self-consistent set of collision cross sections for incident electron energies ranging from thresholds up to 10 MeV. Results are reported for about 40 states with an emphasis given on the ionisation processes. The study of the loss function points out the importance of the inner-shell ionisation, which consumes nearly as much energy as the excitation and the ionisation of the outer shell. Moreover, the authors show that the mean energy of the secondaries ejected from a given shell is about twice the ionisation potential of this shell. As a result, many energetic secondary electrons coming from inner-shell ionisation are present in the plasmas produced by relativistic electron beams.

The flowing afterglow of an Ar-N2 mixed gas plasma gives rise to the recombination of nitrogen atoms according to the reaction N(4S)+N(4S)+(Ar-N2)KB(V') to N2(B3 pi g,v')+(Ar-N2) N2(B3 pi g,v') to N2(A3 Sigma uv")+hv (first positive system). Quantitative optical spectroscopy measurements of the emission spectra of the N2(B3 pi g-A3 Sigma u) transition have allowed determination of the total KB and individual KB(v') rates of atomic nitrogen recombination into excited N2 molecules in the B3 pi g state with upper vibrational levels v' between 1 and 12. The active nitrogen atoms are produced by dissociation of N2 molecules in a surface-wave-induced microwave discharge (2450 MHz) sustained in an open-ended dielectric tube. The discharge is operated at atmospheric pressure and the absorbed microwave power is about 200 W for a 5 cm discharge length.

For pt.I see ibid., vol.19, p.761 (1986). The apportionment of the energy deposited in argon by a relativistic electron beam (REB) is studied in the context of the Continuous Slowing Down Approximation (CSDA). The deposition efficiencies of many argon states are presented, with special attention being paid to forbidden states excitations and inner-shell ionisations. Study of the processes leading to plasma formation shows the existence of two separated energy domains. For primary energies lower than 10 keV, the ionisation of argon is mainly due to direct pumping by the beam, while for higher energies the plasma is essentially produced via secondary and high-order generation cascades of electrons. Their contributions to the ionisation of the M-shell or to the excitation of the allowed states amount to about 70% and constitute the totality of the forbidden states production. The authors emphasis the fact that the cascade electrons arising from inner-shell ionisations are responsible for about 40% of the population of the various argon states.

We report on a microstrip line structure able to sustain plasmas up to five bars of a He/Xe/HCl mixture, with good stability and reproducibility and without preionization of the mixture. The microwave power coupling has been characterized and the incoherent ultraviolet-308 nm emission has been studied by means of time-resolved spectroscopy.