Neutron Detection with Silicon Devices

Most neutron detectors use some type of conversion material to convert the incident neutron into secondary charged particles, which can then be detected inside the detector bulk afterward. In this way, semiconductor detectors incorporating neutron reactive material on top of a diode substrate can be used as a neutron detector. These reactions emit charged particles and recoil nucleus with energies high enough to be distinguished from the gamma ray background. Based in the experience in microfabricated radiation detectors, CNM-IMB (national center of microelectronic at Barcelona, Spain) has started a new research line in solid state neutron detectors for imaging or dissymmetry. Geant4 Monte-Carlo simulation package was used to forecast the detection efficiency of planar structures. The simulated detectors were covered with a layer of Boron, therefore, a simple silicon neutron detector is a combination of a planar diode covered with a neutron converter layer. At the same time, initial experimental measurements of silicon pad detectors covered with neutron converts are been carried out in the autonomous University of Barcelona with a neutron source (²⁴¹ Am-Be) with interesting results.