The n_TOF-EAR2 facility at CERN: neutron flux determination and $^{33}$S(n,$\alpha$)$^{30}$Si cross section measurement; implications in BNCT.

The main aim of this project is the first measurement of the $^{33}$S(n,$\alpha$)$^{30}$Si cross section at the neutron time-of-flight n_TOF facility at CERN from few meV to10 keV, covering the existing lack of experimental data. The measurement was performed in the summer of 2015 in the new beam line of the n_TOF facility, n_TOF-EAR2. In order to complete the measurement, the characterization of the neutron beam becomes essential to determine the cross section. Therefore, an important part of the present work is dedicated to the description of the n_TOF-EAR2 features and, in particular, to the evaluation of the neutron flux of the facility by means of combining different cross section measurements considered standards. $^{33}$S is a stable isotope of sulphur of interest in Neutron Capture Therapy for treating superficial tumours. The data obtained was included in Monte Carlo simulations of the kerma rate for studying the effect of $^{33}$S in the therapy.