XLIII. Excitation of the Balmer series lines in hydrogen spark channels

Abstract

Experiments on the determination of the Balmer series decrements, i.e. the intensity ratios for certain Balmer lines, for short sparks in hydrogen at 1 atmosphere pressure, are discussed. From the results, deductions concerning the excitation conditions in the spark channels are made and it is shown that, whilst the results are complex, a pure recombination or thermal excitation mechanism is unlikely to explain them and that electron excitation appears to be the operative mechanism for the conditions studied.