Using a Cerenkov detector in HVL measurements for industrial electron linacs

The environmental background scattering and unstable low energy component of bremsstrahlung spectra often distort the half-value layer (HVL) measurements using conventional detectors. Here we demonstrate that a Cerenkov detector with a detection threshold in the low energy range can successfully reduce the effect of these systematic errors and improve the sensitivity of the HVL measurements. Our experiments are conducted on a system based on a dual-energy electron linac. Comparing the results obtained by a Cerenkov detector and those by a CsI(Tl) detector shows the robustness of the Cerenkov detector. Moreover, the energy response calculation also shows that the Cerenkov detector is more sensitive to the quality of the bremsstrahlung spectra than the CsI(Tl) detector. (C) 2011 Elsevier Ltd. All rights reserved.