Development and Some Application of the Multistep Avalanche Chambers pp. 243-340
Authors: (D.A. Abdushukurov, Physical-Technical Institute of the Academy of Sciences of the Republic of Tajikistan, Dushanbe, Republic of Tajikistan)
Abstract: The gas position-sensitive detectors (GPSD) play the important role in high-energy physics experiments, and in the applied areas. Besides of the coordinate information on tracks of charged particles, these detectors in some cases allow to obtain as well the information on ionization losses of radiation and a time of flight of particles that allows using them for identification of registered particles. Multistep avalanche chambers (MSAC) have been offered for the first time in group of G. Charpak in the CERN. Originally they developed for the purpose of increasing counting rate of the multiwire gas detectors. In during of examination of characteristic performances of the MSAC other advantages of these detectors were found out also: a high gas amplification factor (106 107); high position accuracy on both (Х and Y) coordinates; proper to them «collimating effect» and others. MSAC mechanically consists from multiwire proportional chamber (MWPC) and had over it in a common gas space pre-amplification and the drift gaps. Detectors work on gas mixtures on the basis of rare gases with small additives of organic compounds at a normal pressure. The basic mechanism of gas amplification in MSAC is development of the electron- photon avalanche in outside of MWPC, in a plane-parallel gap of a pre-amplification in the strong and homogeneous electric field. The formed electrons are transferred in MWPC for the next amplification and recording. In further have been developed as well the low pressure multistep avalanche chambers (LPMSAC) working on steams of hydrocarbons at pressure 5-20 torr.