Cosmic Ray Tests of the Prototype TPC for the ILC Experiment
Abstract
A time projection chamber (TPC) is a strong candidate for the central tracker of the international linear collider (ILC) experiment and we have been conducting a series of cosmic ray experiments under a magnetic field up to 4 T, using a small prototype TPC with a replaceable readout device: multi-wire proportional chamber (MWPC) or gas electron multiplier (GEM). We first confirmed that the MWPC readout could not be a fall-back option of the ILC-TPC under a strong axial magnetic field of 4 T since its spatial resolution suffered severely from the so called E x B effect in the vicinity of the wire planes. The GEM readout, on the other hand, was found to be virtually free from the E x B effect as had been expected and gave the resolution determined by the transverse diffusion of the drift electrons (diffusion limited). Furthermore, GEMs allow a wider choice of gas mixtures than MWPCs. Among the gases we tried so far a mixture of Ar-CF4-isobutane, in which MWPCs could be prone to discharges, seems promising as the operating gas of the ILC-TPC because of its small diffusion constant especially under a strong magnetic field. We report the measured drift properties of this mixture including the diffusion constant as a function of the electric field and compare them with the predictions of Magboltz. Also presented is the spatial resolution of a GEM-based ILC-TPC estimated from the measurement with the prototype.
Cite
@article{arxiv.0905.2655,
title = {Cosmic Ray Tests of the Prototype TPC for the ILC Experiment},
author = {K. Ackermann and S. Arai and D. C. Arogancia and A. M. Bacala and M. Ball and T. Behnke and H. Bito and V. Eckardt and K. Fujii and T. Fusayasu and N. Ghodbane and H. C. Gooc and T. Kijima and M. Hamann and M. Habu and R. -D. Heuer and K. Hiramatsu and K. Ikematsu and A. Kaukher and H. Kuroiwa and M. E. Janssen and Y. Kato and M. Kobayashi and T. Kuhl and T. Lux and T. Matsuda and S. Matsushita and A. Miyazaki and K. Nakamura and O. Nitoh and H. Ohta and R. L. Reserva and K. Sakai and N. Sakamoto and T. Sanuki and R. Settles and A. Sugiyama and T. Takahashi and T. Tomioka and H. Tsuji and T. Watanabe and P. Wienemann and R. Wurth and H. Yamaguchi and M. Yamaguchi and A. Yamaguchi and T. Yamamura and H. Yamaoka and T. Yazu and R. Yonamine},
journal= {arXiv preprint arXiv:0905.2655},
year = {2014}
}
Comments
4 pages, 8 figures. Preprint submitted to TIPP09 Proceedings