Figure 1.
Cross sectional diagrams showing the concept of (a) MICROMEGAS and (b) GEM, where x rays ionize a gas and the resulting electrons undergo avalanche in a gain region. (c) Cross sectional diagram showing a solid state a-Se structure proposed by Lee (Ref. 32) in which the a-Se layer is partitioned into drift and gain regions. Shaded areas denote region of a single del.