Development of a method for the on-line spectral characterization of Bremsstrahlung photons from an electron accelerator

Abstract

The use of irradiators based on electron accelerator technologies coupled with an electron–photon conversion target requires an accurate and continuous characterization of the Bremsstrahlung spectrum produced. The indirect methods developed so far are either unsuitable for the constraints of on-line measurement or they call for excessively invasive devices. We present here a method for on-line reconstruction of the photon spectrum from the measurement of the energy deposited in a scintillator irradiated on its edge, using a simple, compact and robust device.The approach to reconstructing the Bremsstrahlung spectrum from the measurement of its energy deposited in a scintillator, translates mathematically into the solution of a linear inverse problem. The classical resolution of the problem is disrupted by its very nature and by the presence of noise in the experimental measurement of the deposited energy in the scintillator, but it is possible to apply methods compatible with the on-line constraint. In this paper, a method is implemented on the basis of Tikhonov regularization and, with the use of an effective tool, allows a multi-parametric study to be carried out in order to meet the on-line measurement constraint. In particular, the aim is to optimize the choice of scintillator and the properties of the acquisition system to be used.