Resistive plate chamber for thermal neutron detection

The possibility to detect thermal neutrons with single gap resistive plate chambers (RPCs) has been investigated. The development of the detector has been performed in the frame of the detection and imaging of antipersonnel land-mine by neutron back-scattering (DIAMINE) European Project for humanitarian de-mining. The RPCs are simple devices widely used in many particles physics experiments as trigger detectors because of their fast response and good spatial resolution. The RPC detects the charged particles generated by neutrons via the (n,alpha) reaction on boron. A (B4C)-B-10 thin coating on the inner surface of one RPC electrode is used as thermal neutron converter. A simulation study has been performed to optimize the converter thickness and the RPC working parameters. Tests on converter samples have been performed with a thermalized Cf-252 source in order to evaluate the conversion efficiency. A first detector prototype has been realized and tested with cosmic rays and thermal neutrons. Results of simulation and experimental measurements of conversion efficiency, together with the description of the RPC prototype, are presented.