Large area and high-pressure GPSC/MSGC for space solar X-ray spectrometry

The study of solar X-ray emissions can be very useful to predict and prevent the undesirable consequences of charged particles generated by solar flares on Earth, since charged particles take about 20 to 40 hours to reach Earth, while X-rays that are simultaneously emitted by the same solar flares only take about 8 minutes. Herein, we present a large area window (20 cm/sup 2/) and high-pressure (up to 5 atm) hybrid gas proportional scintillation counter/microstrip gas chamber (GPSC/MSGC) for a satellite borne experiment to study solar flare X-ray emissions in the energy range between 20 keV and 80 keV. Xenon filled GPSC/MSGCs are low production cost and low power consumption detectors that provide large detection areas, room temperature operation and optimal energy resolution for solar X-ray observations. Therefore, the performances of a laboratory prototype designed to study solar X-rays was analysed. Namely the energy resolution as a function of the Xe pressure (1 atm to 5 atm), since for energies above 60 keV the gas pressure is a critical parameter to detection efficiency. The results obtained for the energy resolution dependence with the gas pressure (about 6.5% up to 4 atm) will be presented and discussed.