The diodes Si-1 and Si-2 are long base silicon diodes ( LBSD ) developed for measurement of kerma from heavy particles, particularly fast neutrons. The main physical effect, which is used for kerma measurement, is the change of t as the minor charge carriers lifetime in silicon after irradiation due to radiation damage in the crystal lattice. Because of the difficulties in lifetime measurement, the forward bias voltage drop on the diode is measured. The change of this voltage D U i.e. the difference between the voltage U after irradiation and the initial voltage U 0 is taken as a measure of the radiation damage and is approximately linear function of kerma from fast neutrons. Both types has very low sensitivity for gamma irradiation and so they can be used in mixed gamma - neutron fields. Diodes Si-1 and Si-2 differs in technical specifications, type Si-2 is more sensitive and therefore useful in personal dosimetry.
Additional information see Catalog