Comparative studies of MSGC and GEM for photon and electron detection at ambient conditions

Experimental work relevant to the electron and photon detection in X-ray Absorption Spectroscopy (XAS) experiments is described using a Micro-Strip Gas Chamber (MSGC) and a Gas Electron Multiplier (GEM) operated at atmospheric pressure. XAS studies at ambient conditions dictate the use of predominately Helium counter gas mixture with minimal quench gas concentration whilst attaining charge gains in the 104 region. We present results on the charge gain for both MSGC and GEM detectors using He/iso-C4H10 based gas mixtures. Pulse-height distributions due to the Total Electron Yield (TEY) arising from interactions between 8.05 keV X-rays and Titanium sample, i.e. photoelectrons, auger electrons and fluorescent photons, are also presented. Employing a repelling voltage grid close to the sample surface permitted the separation of TEY and the Fluorescent Yield (FY) signal.