Pulsed Neutron Dose Monitoring - A New Approach

Radiation protection at accelerator facilities is frequently dealing with pulsed radiation fields and with high particle energies. Therefore a new method for pulsed high-energy neutron dose monitoring with an active device was developed and investigated. The concept is based on the idea of storing pulsed dose information in an instable nuclear state with a short half-life. High-energy neutrons are hitting on a ¹²C target and are generating ⁹Li nuclei with a half-life of 178 ms. The daughter nuclide disintegrates with neutron emission. Berthold LB 6411 standard rem-counters were used as neutron detectors and as carbon targets. The data were recorded in time-resolved readout utilizing a newly developed data-logger, which auto-synchronizes with pulsed radiation fields. Measurements with pulsed high energy neutron fields were performed and calibrated and the analysis of the delayed neutrons provides neutron dose information without being affected by dead-time.