Detectors for time-of-flight fast-neutron radiography 1. Neutron-counting gas detector

One of our two methods for fast-neutron imaging with spectrometric capability is presented here. It is a neutron-counting technique based on a hydrogenous neutron converter coupled to Gaseous Electron Multipliers (GEM). The principles of the detection techniques and the optimization of the converter, electron amplification and the readout are described. Evaluation of the properties is derived from a experiment in a pulsed neutron beam of spectral distribution between 2 and 10 MeV.