X-ray imaging with GEMs using $100\,\mu$m thick foils

Autor: da Luz, H. Natal, Mir, J. A., Carvalho, X., Santos, J. M. F. dos
Rok vydání: 2013
Předmět:
Druh dokumentu: Working Paper
DOI: 10.1088/1748-0221/9/06/C06007
Popis: A simple X-ray imaging system using off-the-shelf electronics and simple reconstruction algorithms aiming a spatial resolution of 1.7 mm ($\sim 3\,\%$ of the detector length) is described in this work. For this, two 100 cm$^2$ Gas Electron Multiplier (GEM) foils with a thickness of 100 \mu m (2-fold thicker than the standard ones) were immersed in a mixture of argon and carbon dioxide (70:30). The charge readout with 2D position determination was done with resistive charge division. Due to their higher thickness with respect to the standard GEMs, the 100 \mu m thick GEM foils were found to be less prone to damage caused by the electrical discharges. X-ray images are shown and some descriptions of the physical processes involved are presented. We describe the advantages of this method that allows counting each X-ray photon or particle entering the detector, its interaction position, as well as measuring of its energy. The results of our present work show a position resolution below 2 mm, being limited by the gas mixture used, and not the detecting system, with a very good cost effectiveness. Future work is being carried out to optimize the present system for a medical application as a proton beam monitor.
Comment: 8 pages, 8 figures, Proceedings of the 15th iWoRiD - International Workshop in Radiation Imaging Detectors
Databáze: arXiv