Cross section measurements of the (131)Xe(p,n) reaction for production of the therapeutic radionuclide (131)Cs.

(131)Cs is an X-ray emitter radioisotope gaining interest in prostate brachytherapy. It is generally produced via the (130)Ba(n,gamma)(131)Ba-->(131)Cs process in thermal-flux reactors. Here we investigate its cyclotron production possibilities. Excitation function of the (131)Xe(p,n)(131)Cs reaction was measured up to 35MeV using the stacked gascell technique and high-resolution X-ray spectrometry. The experimental data were compared with results of the ALICE-IPPE and EMPIRE-II codes and curves taken from the PADF and TENDL database. The calculated integral yield was 17MBq/microAh in the energy range E(p)=20-->7MeV. Comparison of cyclotron and reactor production routes was given.