Gas bremsstrahlung and induced photoneutrons in the NSRRC's electron storage ring: A comparison of measurements and simulations

Abstract

This study investigated the characteristics of gas bremsstrahlung and induced photoneutrons from the electron storage ring in National Synchrotron Radiation Research Center (NSRRC). Gas bremsstrahlung is generated in the vacuum chamber of an electron storage ring by interactions of the circulating electrons with the atoms of the residual gas. The emitted photons with sufficiently high energies can further produce neutrons by means of photonuclear interactions. Photoneutrons produced in a lead target struck by gas bremsstrahlung were measured as a function of target thickness by using high-efficiency neutron detectors in a well-defined configuration. A Monte Carlo simulation of the whole process including generation of gas bremsstrahlung, production of photoneutrons and subsequent neutron transport has been performed in an integrated manner and the results were directly compared with the measurements on an absolute basis. The agreement between them is very satisfactory and hence validates the evaluation of the characteristics of gas bremsstrahlung and induced photoneutrons in NSRRC.