Speaker
Eleni Aza
(CERN)
Description
The neutron beam of the n_TOF facility was characterized by means of three triple GEM detectors in EAR1 and the beam dump. A side-on detector employing 10B was used for beam imaging inside the EAR1 via a horizontal and vertical scan for the reconstruction of the entire image and the energy spectrum was measured from the neutron time-of-flight with an efficiency of 4.3% for thermal energies via an externally triggered FPGA-based motherboard. Two head-on detectors with an active area of 10x10 cm2 were used for the beam profiling at the beam dump with a spatial resolution of 8 mm; one employing B4C for slow and the other polyethylene for fast neutrons, so that the spectrum was measured from thermal energies to 1 GeV. The beam diffusion was measured by comparing the spot dimensions of the slow component in EAR1 and the beam dump, while spot size differences were also observed between the fast and slow beam components at the dump. The time-of-arrival of the photon flash emitted after the spallation process on the target was measured at the beam dump with 50 ns accuracy, yielding count losses due to saturation effects.
