Calculation of Primary Electron Collection Efficiency in Gas Electron Multipliers Based on 3D Finite Element Analysis

3차원 유한요소해석을 이용한 기체전자증폭기의 1차 전자수집효율의 계산

  • Kim, Ho-Kyung (School of Mechanical Engineering, Pusan National University) ;
  • Cho, Min-Kook (School of Mechanical Engineering, Pusan National University) ;
  • Cheong, Min-Ho (School of Mechanical Engineering, Pusan National University) ;
  • Shon, Cheol-Soon (School of Mechanical Engineering, Pusan National University) ;
  • Hwang, Sung-Jin (School of Mechanical Engineering, Pusan National University) ;
  • Ko, Jong-Soo (School of Mechanical Engineering, Pusan National University) ;
  • Cho, Hyo-Sung (Department of Radiological Science, BAERI, Yonsei University)
  • 김호경 (부산대학교 기계공학부) ;
  • 조민국 (부산대학교 기계공학부) ;
  • 정민호 (부산대학교 기계공학부) ;
  • 손철순 (부산대학교 기계공학부) ;
  • 황성진 (부산대학교 기계공학부) ;
  • 고종수 (부산대학교 기계공학부) ;
  • 조효성 (연세대학교 방사선학과 원자력기초공동연구소)
  • Published : 2005.06.30

Abstract

Gas avalanche microdetectors, such as micro-strip gas chamber (MSGC), micro-gap chamber (MGC), micro-dot chamber (MDOT), etc., are operated under high voltage to induce large electron avalanche signal around micro-size anodes. Therefore, the anodes are highly exposed to electrical damage, for example, sparking because of the interaction between high electric field strength and charge multiplication around the anodes. Gas electron multiplier (GEM) is a charge preamplifying device in which charge multiplication can be confined, so that it makes that the charge multiplication region can be separate from the readout micro-anodes in 9as avalanche microdetectors possible. Primary electron collection efficiency is an important measure for the GEM performance. We have defined that the primary electron collection efficiency is the fractional number of electron trajectories reaching to the collection plane from the drift plane through the GEM holes. The electron trajectories were estimated based on 3-dimensional (3D) finite element method (FEM). In this paper, we present the primary electron collection efficiency with respect to various GEM operation parameters. This simulation work will be very useful for the better design of the GEM.

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