Speaker
Makoto Kobayashi
(KEK)
Description
Time projection chamber (TPC) is considered as a strong candidate for the
central tracker at the future linear collider experiment because of its large
volume coverage and high three-dimensional granularity. Since the
performance of TPC depends on its readout scheme we have conducted a
series of experiments in order to compare the performance of prototype
TPCs equipped with different readout planes: a conventional multi-wire
proportional chamber (MWPC) or micro pattern gas detectors (GEM and
MicroMEGAS), using common field cage and readout pad plane. The
prototypes, filled with an argon-based gas mixture at the normal pressure,
were subjected to a test beam at KEK under an axial magnetic field of up to
1 tesla. All the prototypes operated stably and provided us with valuable
information. It was found that the obtained spatial resolution was
reproduced both by an analytic formula and a MonteCarlo simulation with
appropriate assumptions on the pad response function and the relative
variance of avalanche fluctuation for a single drift electron. We report here
the results obtained with MPGDs along with experimental details. Also
included are the comparison between GEM and MicroMEGAS, interpretation
of the results and extrapolation to the real TPC.
Author
Makoto Kobayashi
(KEK)
