Measurement of (n,cp) reactions in EAR1 and EAR2 for characterization and validation of new detection systems and techniques

We propose to characterize in EAR1 and EAR2 two detectors now being developed for the measurement of (n,cp) reactions: a GEMpix and an annular silicon detector Neutron Transmutation Doped (NTD). Both systems are intended to cover a large solid angle, have a low sensitivity to the ?-flash, provide good timing information, and especially, allow particle identification with a low threshold. Also, the silicon detector is segmented, thus providing information on the angular distribution of the emitted charged particles. Preliminary tests of both GEMpix and annular silicon detectors have been performed with sources, and with the neutron beam in the dump area of EAR1 in 2021. The results were up to expectations, showing that the performances needed for the (n,cp) physics program are within reach, with both detectors able to collect data up to hundreds of MeV. More dedicated and complete tests are necessary to optimize the operating parameters of the detectors and determine the main characteristics energy resolution, energy and particle identification thresholds, neutron energy range, etc. We plan to use samples of polyethylene, pure Carbon, and Aluminum, whose cross-sections are relatively well known or have been already studied at n_TOF. Moreover, we propose to measure the 12C(n,p)12B reaction with the annular silicon detector, to2 compare the results with those of a measurement already performed at n_TOF with ?E-E technique and thus validate this technique. Further tests with Aluminum Oxide (Al2O3) will help to characterize the identification capability and the energy threshold for the alpha particles.