{'fraction_non_alphanumeric': 0.032852564102564104, 'fraction_numerical': 0.019230769230769232, 'mean_word_length': 4.502202643171806, 'pattern_counts': {'":': 0, '<': 1, '<?xml version=': 0, '>': 1, 'https://': 0, 'lorem ipsum': 0, 'www.': 0, 'xml': 0}, 'pii_count': 0, 'substrings_counts': 0, 'word_list_counts': {'cursed_substrings.json': 0, 'profanity_word_list.json': 0, 'sexual_word_list.json': 0, 'zh_pornsignals.json': 0}}
Measurement of Townsend's first ionization coefficient for air in transverse electric and magnetic fields

The measurements of the first ionization coefficient α/p for air, without and with transverse magnetic fields, are reported in this paper. These were carried out using coaxial cylindrical electrodes to reduce the loss of electrons due to their drift in the E×H direction. The range of measurement covered the values of E/p between 200 and 600 V cm−1 torr−1 and those of H/p between 200 and 1400 G torr−1. The validity of the equivalent pressure concept was tested for the complicated medium like air. It has been shown that a satisfactory agreement between the theoretical and experimental values of α/p, H/p and E/p was obtained for low values of E/p (<300 V cm−1 torr−1) provided the collision frequency was taken to be an increasing function of E/p, instead of a constant as was assumed for hydrogen. At higher values of E/p (> 300), however, the observed values of α/p, H/p and E/p were below those calculated on the basis of the equivalent pressure concept. A few measurements of α/p were also carried out using the pressure variation technique, and its operational utility has been established from the identical nature of the results.