Space charge effect measurements for a multi-channel ionization chamber used for synchrotron radiation

Abstract

A new Multi-channel ionization chamber which can be filled with noble gasses N2, Ar and Xe with controlled inner pressure up to 30 bar is build. The detector is a part of the experimental setup used in the k-edge digital subtraction angiography project, which will be used for correcting the angiography images taken by another detector at the same time. In this work the space charge effect is measured with very high synchrotron photons intensity from EDR beam line at BESSYII. Time response measurement is carried out by filling the chamber with different gasses pressure of argon methane mixture of (90%:10%) and pure nitrogen gas, using a lead slit chopper for pulsating the incoming synchrotron beam. The output current signal is measured with tuning the applied high voltage from recombination regime up to saturation regime. The numerical simulation is applied to understand the effect of the space charge, recombination effects and the charge dynamics behavior inside the ionization chamber.