Characterization of Large GEM Module for the Tracker at Jlab Hall A
1 Dipartimento di Fisica ed Astronomia, Università, di Catania, via Santa Sofia 64, I-95123 Catania, Italy
2 INFN - Sezione di Catania, via Santa Sofia 64, I-95123 Catania, Italy
3 INFN - Sezione di Roma La Sapienza, P.le Aldo Moro, 2 I-00185 Roma, Russia
4 Istituto Superiore di Sanità, viale Regina Elena 299, I-00161 Roma, Italy
5 NFN - Sezione di Genova, via Dodecaneso 33, I-16146 Genova, Italy
6 INFN - Sezione di Lecce, via Arnesano, I-73100 Lecce, Italy
a e-mail: firstname.lastname@example.org
Published online: 2 June 2015
A new Large-Acceptance Forward Angle Spectrometer (Super BigBite) is under development at JLab/Hall A for the upcoming experiments in Hall A at Jefferson Lab where a longitudinally polarized electron beam of 11 GeV is now available. This beam, combined with innovative polarized targets will provided luminosity up to 1039/(s·cm2) opening exciting opportunities to investigate unexplored aspects of the inner structure of the nucleon. The tracker of this new apparatus is based on the Gas Electron Multiplier (GEM) technology, which has been chosen to optimize cost/performance, position resolution and to meet the high hit rate (>1 MHz/cm2). The first GEM detector modules, designed and built by the INFN Collaboration JLAB12, were tested at the DESY test beam facility in Hamburg, by using an electron beam with energy ranging from 2.0 to 6.0 GeV. In particular, three 40x50 cm2 GEM chambers were equipped with a new implementation of the APV25 readout chip. Measurements were performed at different impact points and angles between the electron beam and the plane of the GEM chambers, with one large chamber in a solenoid magnetic field up to 500 Gauss. In this paper we present the technical features of the tracker and comment on the presently achieved performance.
© Owned by the authors, published by EDP Sciences, 2015
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