Théorie de la décharge haute fréquence dans les gaz aux faibles pressions. Étude expérimentale des sources d’ions du type haute fréquence

The low-pressure transition from diffusion-controlled to multipacting gas breakdown

“…The wide flat maximum of the curve on the right of the mean-free-path limit is consistent with Salmon's [7] theoretical expectation of a pressure-independent voltage breakdown, when wall emission of secondaries becomes dominant also at pressures higher than the mean-free-path limit. Thus, when pressure is decreased, the breakdown voltage at first increases and then decreases towards the multipacting limit value.…”

“…The possibility that secondary emission from the walls, rather than ionization of the gas molecules, be the main source of electrons determining breakdown also at pressures just above the mean-free-path limit values has been first considered and theoretically studied by Salmon [7], who has found that in this case the breakdown r.f. voltage becomes pressure independent, in reasonably good agreement with experimental results reported in the literature for hydrogen and argon discharges in pyrex tubes with external electrodes and gas pressures from 8 to 50 mTorr.…”

Rf breakdown of low-pressure gas and a novel method for determination of electron-drift velocities in gases

“…However, the obtained equation for the gas breakdown in the rf field gave an unsatisfactory description of the recorded breakdown curves [15]. Salmon [23], starting from the work by Kihara [22], obtained an analytical expression for the electron distribution function over velocities in the rf field and made some remarks concerning the role played by the secondary electron emission in the rf gas breakdown [24]. In an attempt to improve the agreement between the theory [22] and experiments [15] Sen and Ghosh [25] suggested that one should determine numerical values of molecular constants used in [22] from experimental data rather than from the form of the models adopted in [22].…”