Speaker
Florian Haas
(Technische Universitat Munchen)
Description
For its physics program with a high-intensity hadron beam of 2·10 7
particles/s, the COMPASS experiment at CERN requires tracking of charged
particles scattered by very small angles with respect to the incident beam.
While good resolution in time and space is mandatory, the challenge is
imposed by the high beam intensity, requiring radiation hard detectors
which add very little material to the beam path in order to minimize
secondary interactions. To this end, a set of triple-GEM detectors with pixel
readout in the beam region and 2-D strip readout in the periphery is being
built. The pixel size has been chosen to be 1×1 mm 2, which constitutes a
compromise between spatial resolution and number of readout channels.
Peripheral to the pixel area, a 2-D strip readout with a pitch of 400 μm has
been realized on the same printed circuit. In total an active area of 10×10
cm 2 is covered using 2048 readout channels. An analogue readout via the
APV25-S1 ASIC has been chosen to profit from amplitude measurements on
neighboring strips or pixels during clustering. A detector prototype has been
tested successfully in the 5 · 10 7 μ/s COMPASS muon beam, as well as in a
focused hadron beam. The design of the detector and first results concerning
its performance as a beam tracker will be presented.
Author
Florian Haas
(Technische Universitat Munchen)
Co-author
Bernhard Ketzer
(Institut fuer Theoretische Physik)
