Dear Bernhard,

Idea from the University of Glasgow:

We propose to develop a Radial Time Projection Chamber (RTPC) for use in high-luminosity fixed-target electron scattering experiments. The RTPC would surround a thin "straw" gaseous H2 or D2 target up to 40cm long and with an electron beam current of 50 micro amp a luminosity of ~10^{^37} /(cm^{^2}.s) would be obtained. The objective is to measure tagged structure functions, using the recoil tagging method. This implies that the RTPC has to be sensitive to protons of momentum <~ 100 MeV/c. It would use cooled He (the target straw would also be cooled) as the ionisation medium and the detection system would be a cylindrical triple GEM read out by ~50-100k pads. The materials need to be low-Z to avoid unduely large backgrounds from electromagnetic conversion processes.

We are members of the Super BigBite collaboration at Jefferson Lab, who are developing large area planar GEM detectors for tracking on large acceptance spectrometers BigBite and SuperBigBite. We are also active in a working group examining the possibility of recoil-tagging experiments using an RTPC in Hall A of JLab and lead to effort to simulate the effect of background processes at high luminosty. Our group has extensive experience with Geant-4 based applications.

The Glasgow nuclear physics group has 6 faculty members, 4 core research staff, 2 technicians, and 3 research staff engaged in external activities. We have extensive experience in building detector systems for nuclear physics experiments at Jeffson Lab. and Mainz and within the Glasgow physics department we have extensive laboratory space for construction, development and testing of apparatus. We also have up-to-date computing facilities dedicated to nuclear physics, including a large linux-based batch farm.

Best regards, John

-- BernhardKetzer - 11 Feb 2014