| Title: |
Fine-pitch and thick-foil gas electron multipliers for cosmic x-ray polarimeters |
| Authors: |
Tamagawa, Toru; Hayato, Asami; Yamaguchi, Yorito; Hamagaki, Hideki; Hashimoto, Shigehira; Inuzuka, Masahide; Miyasaka, Hiromasa; Sakurai, Ikuya; Tokanai, Fuyuki; Makishima, Kazuo |
| Contributors: |
Turner, Martin J. L.; Hasinger, Günther |
| Source: |
Space Telescopes and Instrumentation II: Ultraviolet to Gamma Ray, Orlando, FL, 24-31 May 2006 |
| Publisher Information: |
Society of Photo-Optical Instrumentation Engineers |
| Publication Year: |
2006 |
| Collection: |
Caltech Authors (California Institute of Technology) |
| Subject Terms: |
Cosmic X-ray Polarimeter; gas electron multiplier; GEM; proportional counter |
| Description: |
We have produced various gas electron multiplier foils (GEMs) by using laser etching technique for cosmic X-ray polarimeters. The finest structure GEM we have fabricated has 30 μm-diameter holes on a 50 μm-pitch. The effective gain of the GEM reaches around 5000 at the voltage of 570 V between electrodes. The gain is slightly higher than that of the CERN standard GEM with 70 μm-diameter holes on a 140 μm-pitch. We have fabricated GEMs with thickness of 100 μm which has two times thicker than the standard GEM. The effective gain of the thick-foil GEM is 104 at the applied voltage of 350 V per 50 μm of thickness. The gain is about two orders higher than that of the standard GEM. The remarkable characteristic of the thick-foil GEM is that the effective gain at the beginning of micro-discharge is quite improved. For fabricating the thick-foil GEMs, we have employed new material, liquid crystal polymer (LCP) which has little moisture absorption rate, as an insulator layer instead of polyimide. One of the thick-foil GEM we have fabricated has 8 μm copper layer in the middle of the 100 μm-thick insulator layer. The metal layer in the middle of the foil works as a field-shaper in the multiplication channels, though it slightly decreases the effective gain. ; © 2006 SPIE. ; Published - 62663W.pdf |
| Document Type: |
book part |
| Language: |
unknown |
| Relation: |
https://authors.library.caltech.edu/communities/caltechauthors/; https://doi.org/10.1117/12.671244; eprintid:84195 |
| DOI: |
10.1117/12.671244 |
| Availability: |
https://doi.org/10.1117/12.671244 |
| Rights: |
info:eu-repo/semantics/openAccess ; Other |
| Accession Number: |
edsbas.83129155 |
| Database: |
BASE |