Neutron spectroscopy with the Spherical Proportional Counter based on nitrogen gas

A novel large volume spherical proportional counter, recently developed, is used for neutron measurements. The pure N2 gas is studied for thermal and fast neutron detection, providing a new way for neutron spectroscopy. The neutrons are detected via the N14(n,p)C14 and N14(n,α)B11 reactions. The detector is tested for thermal and fast neutrons detection with Cf252 and Am241−Be9 neutron sources. The atmospheric neutrons are successfully measured from thermal up to several MeV, well separated from the cosmic ray background. A comparison of the spherical proportional counter with the current available neutron counters is also presented.