We developed a method to make GEM foils with a spherical geometry. Tests of this procedure and with the resulting spherical \textsc{gem}s are presented. Together with a spherical drift electrode, a spherical conversion gap can be formed. This would eliminate the parallax error for detection of x-rays, neutrons or UV photons when a gaseous converter is used. This parallax error limits the spatial resolution at wide scattering angles. The method is inexpensive and flexible towards possible changes in the design. We show advanced plans to make a prototype of an entirely spherical triple-GEM detector, including a spherical readout structure. This detector will have a superior position resolution, also at wide angles, and a high rate capability. A completely spherical gaseous detector has never been made before.
@article{arxiv.0911.3255,
title = {Spherical GEMs for parallax-free detectors},
author = {Serge Duarte Pinto and Matteo Alfonsi and Ian Brock and Gabriele Croci and Eric David and Rui de Oliveira and Leszek Ropelewski and Miranda van Stenis and Hans Taureg and Marco Villa},
journal= {arXiv preprint arXiv:0911.3255},
year = {2010}
}
Comments
Contribution to the 2009 IEEE Nuclear Science Symposium, Orlando, Florida