First Observation of Signals Due to KAERI's 10 MeV Electron Beam by Using GEM Detectors

Department of Physics, University of Texas, Arlington, TX 76019, U.S.A.(Received 12 September 2006)Performance tests of a single channel double Gas Electron multiplier (GEM) detector constructedby the Radiation Detector Development Group of Changwon National University (CNU) and amulti-channel double GEM chamber constructed by the High Energy Physics Group of the Univer-sity of Texas at Arlington was carried out at the Korea Atomic Energy Research Institute (KAERI’s)RF accelerator by using 10-MeV electron beams during May 20 - 26, 2006. In this experiment, weobserved signals by both 10-MeV beam electrons and X-ray photons in the CNU single-channeldouble GEM chamber and in the UTA chamber by using an oscilloscope and photographed wave-forms. By analyzing the chamber output signals on the oscilloscope, computing the number ofX-rays photons produced by bremsstrahlung of the beam electrons in a 2-mm lead plate, calculat-ing the angular distribution of beam electrons caused by multiple scatterings in the lead plate, andestimating the interaction probabilities of X-ray photons in the lead plate, the Ar/CO