Diamond Dosimeter for the Measurement of the Proton Beam Impact Position on a Neutron Spallation Target

Abstract

In close proximity to the spallation neutron source of the neutron time-of-flight facility n_TOF at CERN, diamond dosimeters were installed to characterise the fast neutron beam. The intensity of the 20 GeV/c proton beam from CERNs Proton Synchrotron (PS) is monitored with a beam current transformer (BCT) installed in the PS extraction line to n_TOF. The proton beam position is measured using a SEM grid 3 m before the spallation target. A linear correlation between the horizontal proton beam impact position on the Pb-target and the measured dose of the secondary radiation at the measurement station for each pulse is observed. While the proton beam impact position varies by 22 mm, the normalised dose varies by 17 %. The linearity of the diamond dosimeter and the correlation of proton beam position and detector response are presented.