THEORETICAL CURRENT RESPONSE OF SILICON DETECTORS TO FAST-NEUTRON BEAMS IN MIXED N,GAMMA FIELDS

A theoretical approach is presented improving the knowledge on real ti me fast neutron dosimetry in intense fields. The detector is a reverse biased silicon junction operating at room temperature. The signal rea dout is a current measurement for which the leakage current of the sen sor sets the detector threshold in the range of 1 Sv s(-1) dose rates. The dosemeter energy response as a function of shielding, polyethylen e neutron converters and diode characteristics has been computed to pr ovide a tissue equivalent neutron monitor which is as insensitive as p ossible 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 mon oenergetic radiations (n or gamma) as well as neutron sources. (C) 199 8 Elsevier Science B.V. All rights reserved.