title: Measurement of the (33)S(n,α) cross-section at n_TOF(CERN): Applications to BNCT.
abstract: OBJECTIVE
  The main purpose of this work is to present a new (n,α) cross-section measurement for a stable isotope of sulfur, (33)S, in order to solve existing discrepancies.
  
  
  BACKGROUND
  (33)S has been studied as a cooperating target for Boron Neutron Capture Therapy (BNCT) because of its large (n,α) cross-section in the epithermal neutron energy range, the most suitable one for BNCT. Although the most important evaluated databases, such as ENDF, do not show any resonances in the cross-section, experimental measurements which provided data from 10 keV to 1 MeV showed that the lowest-lying and strongest resonance of (33)S(n,α) cross-section occurs at 13.5 keV. Nevertheless, the set of resonance parameters that describe such resonance shows important discrepancies (more than a factor of 2) between them.
  
  
  METHODS
  A new measurement of the (33)S(n,α)(30)Si reaction cross-section was proposed to the ISOLDE and Neutron Time-of-Flight Experiments Committee of CERN. It was performed at n_TOF(CERN) in 2012 using MicroMegas detectors.
  
  
  RESULTS
  In this work, we will present a brief overview of the experiment as well as preliminary results of the data analysis in the neutron energy range from thermal to 100 keV. These results will be taken into account to calculate the kerma-fluence factors corresponding to (33)S in addition to (10)B and those of a standard four-component ICRU tissue.
  
  
  CONCLUSIONS
  MCNP simulations of the deposited dose, including our experimental data, shows an important kerma rate enhancement at the surface of the tissue, mainly due to the presence of (33)S.
authors.affiliation: Departamento de Física Atómica, Molecular y Nuclear, Universidad de Sevilla, Facultad de Física, Av. Reina Mercedes s/n, E-41012 Seville, Spain; Centro Nacional de Aceleradores (US-JA-CSIC), C/ Thomas Alva Edison 7, E-41092 Seville, Spain.
authors.forename: Marta
authors.initials: M
authors.lastname: Sabaté-Gilarte
authors.affiliation: Departamento de Física Atómica, Molecular y Nuclear, Universidad de Sevilla, Facultad de Física, Av. Reina Mercedes s/n, E-41012 Seville, Spain; Centro Nacional de Aceleradores (US-JA-CSIC), C/ Thomas Alva Edison 7, E-41092 Seville, Spain.
authors.forename: Javier
authors.initials: J
authors.lastname: Praena
authors.affiliation: Departamento de Física Atómica, Molecular y Nuclear, Facultad de Ciencias, Universidad de Granada, E-18071 Granada, Spain.
authors.forename: Ignacio
authors.initials: I
authors.lastname: Porras
authors.affiliation: Departamento de Física Atómica, Molecular y Nuclear, Universidad de Sevilla, Facultad de Física, Av. Reina Mercedes s/n, E-41012 Seville, Spain.
authors.forename: José Manuel
authors.initials: JM
authors.lastname: Quesada
authors.affiliation: Laboratori Nazionali di Legnaro, INFN, Viale dell'Università, 2, 35020 Padova, Italy.
authors.forename: Pierfrancesco
authors.initials: P
authors.lastname: Mastinu
keywords: 33S(n,α) cross-section measurement; Data analysis; Monte Carlo simulations; Neutron capture therapy; n_TOF(CERN)