Triple Gas Electron Multipliers (GEM) for slow and fast neutrons were employed at the n-TOF facility at CERN as online beam imaging monitors and for energy spectra measurements via the time-of-flight technique. The detectors were exposed to the neutron spectrum ranging from thermal to 1 GeV, produced by spallation of 20 GeV/c protons in a lead target with a maximum intensity of 7·1012 protons per pulse. The spectrum and the 2D count distribution of the neutron beam were measured and compared at two distances from the target, 185 m and 200 m. The detectors showed radiation hardness, linear response and the ability to monitor the beam profile online with high spatial resolution.
Aza, E., Magistris, M., Murtas, F., Puddu, S., & Silari, M. (2015). Neutron beam monitoring for time-of-flight facilities with gaseous detectors. Nuclear Instruments and Methods in Physics Research, Section A: Accelerators, Spectrometers, Detectors and Associated Equipment, 806, 14–20. https://doi.org/10.1016/j.nima.2015.09.054