Theoretical current response of silicon detectors to fast neutron beams in mixed n, γ fields

A theoretical approach is presented improving the knowledge on real time fast neutron dosimetry in intense fields. The detector is a reverse biased silicon junction operating at room temperature. The signal readout is a current measurement for which the leakage current of the sensor sets the detector threshold in the range of 1 Sv s−1 dose rates. The dosemeter energy response as a function of shielding, polyethylene neutron converters and diode characteristics has been computed to provide a tissue equivalent neutron monitor which is as insensitive as possible to the gamma photon background. Two Monte Carlo codes, one for the fast neutrons (SEMIC) and for the photon background (MCGET), are used to calculate the current response of the device irradiated by monoenergetic radiations (n or γ) as well as neutron sources.