Micromegas TPC studies at high magnetic fields using the charge dispersion signal
- 作者：M. Dixit ; D. Attié ; A. Bellerive ; K. Boudjemline ; P. Colas ; A. Giganon ; I. Giomataris ; V. Lepeltier ; S. Liu ; J.-P. Martin ; K. Sachs ; Y. Shin ; S. Turnbull
- 关键词：UV photodetector ; Single photon counting ; Pixelized CMOS analog chip
- 刊名：Nuclear Instruments and Methods in Physics Research Section A ; Accelerators ; Spectrometers ; Detectors and Associated Equipment
- 出版年：2007
- 期刊代码：41_01689002
- 类别：ph
- 出版时间：21 October 2007
- 卷：581
- 期：1-2
- 页码：254-257
- 文件大小：154 K
摘要
The International Linear Collider (ILC) Time Projection Chamber (TPC) transverse space-point resolution goal is e="mml3">ef="/science?_ob=MathURL&_method=retrieve&_udi=B6TJM-4PB0PFX-14&_mathId=mml3&_user=10&_cdi=5314&_rdoc=56&_acct=C000050221&_version=1&_userid=10&md5=5da103a98d0b16fb3448660db6df0617">
encedirect.com/cache/MiamiImageURL/B6TJM-4PB0PFX-14-D/0?wchp=dGLzVzz-zSkzS" alt="Click to view the MathML source" align="absbottom" border="0" height=16 width=48> for all tracks including stiff e="mml4">e="text-decoration:none; color:black" href="/science?_ob=MathURL&_method=retrieve&_udi=B6TJM-4PB0PFX-14&_mathId=mml4&_user=10&_cdi=5314&_rdoc=56&_acct=C000050221&_version=1&_userid=10&md5=8011fec54bde481c5cf2ae25ef9a7e42" title="Click to view the MathML source">90encedirect.com/scidirimg/entities/2218.gif" alt="ring operator" border=0> tracks with the full e="mml5">ef="/science?_ob=MathURL&_method=retrieve&_udi=B6TJM-4PB0PFX-14&_mathId=mml5&_user=10&_cdi=5314&_rdoc=56&_acct=C000050221&_version=1&_userid=10&md5=2c356dc7c80e19d407ac4d76950360fd">encedirect.com/cache/MiamiImageURL/B6TJM-4PB0PFX-14-H/0?wchp=dGLzVzz-zSkzS" alt="Click to view the MathML source" align="absbottom" border="0" height=12 width=37> drift. A Micro-Pattern Gas Detector (MPGD) readout TPC can achieve the target resolution with existing techniques using 1 mm or narrower pads at the expense of increased detector cost and complexity. The new MPGD readout technique of charge dispersion can achieve good resolution without resorting to narrow pads. This has been demonstrated previously for e="mml6">ef="/science?_ob=MathURL&_method=retrieve&_udi=B6TJM-4PB0PFX-14&_mathId=mml6&_user=10&_cdi=5314&_rdoc=56&_acct=C000050221&_version=1&_userid=10&md5=8f3b10f27f625f6d2352c329ab8dc528">encedirect.com/cache/MiamiImageURL/B6TJM-4PB0PFX-14-J/0?wchp=dGLzVzz-zSkzS" alt="Click to view the MathML source" align="absbottom" border="0" height=13 width=95> pads with GEMs and Micromegas in cosmic ray tests and in a KEK beam test in a 1 T magnet. We have recently tested a Micromegas-TPC using the charge dispersion readout concept in a high field super-conducting magnet at DESY. The measured Micromegas gain was found to be constant within 0.5%for magnetic fields up to 5 T. With the strong suppression of transverse diffusion at high magnetic fields, we measure a flat e="mml7">ef="/science?_ob=MathURL&_method=retrieve&_udi=B6TJM-4PB0PFX-14&_mathId=mml7&_user=10&_cdi=5314&_rdoc=56&_acct=C000050221&_version=1&_userid=10&md5=6f75ce6161218b5f73b64a34f56eea5a">encedirect.com/cache/MiamiImageURL/B6TJM-4PB0PFX-14-K/0?wchp=dGLzVzz-zSkzS" alt="Click to view the MathML source" align="absbottom" border="0" height=16 width=41> resolution at 5 T over the full 15 cm drift length of our prototype TPC.