Multichannel wire gas electron multipliers with 1- and 3-mm gaps

The operation of multichannel wire gas electron multipliers (MWGEMs) with gaps between electrodes δ = 1 and 3 mm, when the chamber is filled with commercial neon under a 0.4- and 1.0-atm (abs.) pressure and irradiated with α and β particles, is studied. The following maximal proportional electron multiplication coefficients are obtained: 6 × 103 (α, irradiation, δ = 3 mm, 1 atm, and 20% streamers), 1.2 × 104 (β−, 3 mm, 1 atm, and 50% streamers), 6 × 103 (α, 3 mm, 0.4 atm, and 20% streamers), and 105 (β−, 3 mm, 0.4 atm, and 50% streamers). The maximal proportional electron multiplication coefficients are obtained in the MWGEM and its anode (induction) gap in the sequential electron multiplication mode: 1.08 × 105 (β−, 1 mm, 0.4 atm, 50% streamers), 2 × 106 (β−, 3 mm, 0.4 atm, 20% streamers), and 1.12 × 105 (α, 3 mm, 0.4 atm, 50% streamers).