Position-sensitive neutron detection with (LiF)-Li-6 layers on silicon semiconductors

The detection of thermal neutrons absorbed by a thin layer of (LiF)-Li-6 in front of a p(+) n n(+) Silicon diode has been demonstrated. With such a layer attached to a strip diode a linear position-sensitive neutron detector is presented. A spatial resolution of 1.25 mm was measured, and it is equal to the pitch of the 24 metal strips on the 30 mm x 30 mm diode array. The absorption probability is 10% and 30% and for double diodes this leads to a detector efficiency of 5% and 15% for thermal and subthermal neutrons, respectively. These values can be improved by various means. For MeV gamma rays an extremely low sensitivity of less than 10(-6) has been measured with Co-60 and Cs-137 and with gamma rays generated by stopping a strong neutron beam with Cadmium in front of the detector. Further properties of this new neutron detector based on absorption in (LiF)-Li-6 and generation of charge carriers within the depletion region of a Silicon diode along the trace of generated high energy H-3(+) ions are presented.