Diagnostics of the Proton Beam Position Using the Luminescence of a Lithium Neutron-Generating Target

A compact accelerator-based neutron source [1] has been proposed and created at the Budker Institute of Nuclear Physics in Novosibirsk, Russia. An original design tandem accelerator is used to provide a proton beam. The neutron flux is generated as a result of the ⁷Li (p, n) ⁷Be threshold reaction using the solid lithium target. A beam shaping assembly is applied to convert this flux into a beam of epithermal neutrons with characteristics suitable for BNCT (boron neutron capture therapy) [2]. In addition to the main purpose the neutron source is used to measure the content of impurities in ceramic samples developed for ITER [3], for measurement of the cross section of the reaction of inelastic scattering of a proton on a lithium nucleus. The neutron source is planned to be used for radiation testing of optical fibers of the laser calorimeter calibration system of the CMS [4] for the High Luminosity Large Hadron Collider (CERN). The need to provide the long-term stable generation of neutrons requires the development of diagnostic techniques that display relevant information from various subsystems of the neutron source in real time. We have developed and put into operation diagnostics for monitoring the position of the proton beam on a lithium target, which is also resistant to radiation exposure.