Patent ID: 6133575
Filing Date: 2000-10-17
Classification: G01T,H01J

Abstract:
Ionizing particle detector comprising:a gas chamber (2);first (4), second (6) and third (8) plane electrodes placed in this order in the chamber and kept parallel with each other, the first and second electrodes delimiting a conversion gap (C) in which particles generate electrons, the second and third electrodes delimiting an amplification gap (A) in which said electrons are multiplied by an avalanche process, the second electrode being perforated by holes (18) and forming a cathode (6), the third electrode forming an anode (8) and comprising a set of elementary anodes (14; 29; 14; 19) electrically insulated from each other; andpolarization means (10) capable of raising the first electrode (4) to a first potential, the cathode (6) to a second potential, and elementary anodes (14; 29; 14; 19) to a third potential higher than the second potential, said polarization means thus being capable of creating electric fields (E1, E2) in the conversion (C) and amplification (A) gaps respectively,wherein the distance D between the cathode (6) and the anode (8) is less that 500 .mu.m and the ratio R of the intensity of the electric field (E2) created in the amplification gap (A) to the intensity of the electric field (E1) created in the conversion gap (C) exceeds 10, and wherein the detector further comprises means for amplifying and processing electric signals from the elementary anodes when the electrons are multiplied in the amplification gap.