Development of self-powered neutron detectors used in nuclear medicine for the measurement of neutron flows during treatment of boron neutron therapy

Purpose The Self Powered Neutrons Detectors (SPND) have the advantage of not requiring a high voltage power supply for their operation and are small in size, enhancing the interest of these detectors in medicine.
Methods In this context, we have developed a thermal neutron detection system based on SPND. This detector was placed in the thermal channel of our nuclear research reactor; where the values of the current for each detector have been recorded as a function of time, with a chain in a current mode where electrometers without HV were used.
Results We performed the real-time measurement of neutron flux during boron neutron capture therapy or boron neutron therapy, the different materials constituting the SPND detectors have been carefully chosen for this application. These detectors were tested at a power of four MW corresponding to a neutron flux of 10⁹ n cm^-2 s^-1.
Conclusions The usefulness of ¹⁰³Rh-SPND is for online measurement of thermal neutron flux on BNCT patients has been demonstrated based on an appropriate calibration of the thermal neutron spectrum.