The theoretical and practical sensitivities of gas-focused cathode-ray oscillographs, and the effects of the gas on their performance

A brief survey is given of recent modifications in the construction of gas-focused cathode-ray oscillographs, and some of the resulting improvements in performance are described. The authors then summarize recent work of other investigators which has a direct bearing on the subject matter of the present paper. A comparison is made of the electrostatic sensitivities obtained from simple electron dynamics and that found by experiment for two focusing gases, argon and helium; an explanation is advanced for the results obtained. The phenomenon of origin distortion is next considered, and results are given showing its variation with gas pressure for hydrogen, and with the frequency of the deflecting voltage between 0 and 1.25 ×104 cycles per sec. for hydrogen, helium, and argon, as focusing gases. The dependence of gas focusing on the transverse speed of the electron beam is discussed, and photographs are given which demonstrate this dependence in the cases of hydrogen, helium, and argon. The paper concludes by indicating the practical importance of the results given.