Ways of providing radiation resistance of magnetic field semiconductor sensors

Abstract

Hall magnetic field sensors resistant to hard ionizing irradiation are being developed for operation under the radiation conditions of space and in charged particle accelerators. Radiation resistance of the sensors is first determined by the properties of semiconductor materials of sensitive elements; we have used microcrystals and thin layers of III–V semiconductors. Applying complex doping by rare-earth elements and isovalent impurities in certain proportions, we have obtained magnetic field sensors resistant to irradiation by fast neutrons and γ-quanta. Tests of their radiation resistance were carried out at IBR-2 at the Joint Institute for Nuclear Research (Dubna). When exposed to neutrons with E=0.1–13 MeV and intensity of 10 10 n cm −2 s −1, the main parameter of the sensors—their sensitivity to magnetic fields—changes by no more than 0.1% up to fluences of 10 14 n cm −2. Further improvement of radiation resistance of sensor materials is expected by means of a combination of metallurgical methods of complex doping with the technology of radiation modification, which includes an interchanging of nuclear doping and fast neutron irradiation with thermoprocessing cycles. A special magnetometric system is to be developed in which the main element is the functionally integrated magnetometric transducer consisting of a semiconductor Hall microgenerator and a copper microsolenoid, which forms the actuating field around the microgenerator. The application of such a magnetometric system with radiation resistant magnetic field sensors will provide magnetic field measurements with an accuracy of 0.1% under hard radiation conditions.