Speaker
Description
With the growing demand for neutrons in applications such as detector calibration, device irradiation, and cross-section measurements, neutron sources are advancing toward higher energy and higher flux. In Beijing, China, two neutron beamlines, a quasi-monoenergetic one and a white light one, based on a proton cyclotron with a maximum energy of 50 MeV is under construction and preparation. We designed a quasi-monoenergetic neutron beamline, focusing on the target chamber and collimator. Lithium was selected over beryllium as the target material due to its superior quasi-monoenergetic peak performance. Parametric studies on lithium thickness revealed its impact on the neutron peak characteristics. Energy loss of protons through titanium films and argon gas was evaluated to guide chamber design. Neutron spectra and fluxes were simulated at various positions, leading to an optimal collimator length of 2 m based on flux and peak ratio. Regarding the white light beamline, detailed simulations and discussions were conducted on the composition of the shielding and collimation structure, leading to the determination of the final design. This approach significantly reduced the amount of cast iron required, resulting in a notable decrease in overall weight. These above-mentioned works provide key data for the beamline's construction and operation.
