Detectors for Pulsed Neutron Beams
The need of radiation detectors capable to measure efficiently in pulsed neutron fields is attracting widespread interest for application such as radiation protection and beam diagnostics in accelerators. Since the sixties, numerous investigations focused on the development of detectors specifically conceived to work in pulsed fields. This is a major issue at particle accelerators, where pulsed neutron and gamma fields are present because of beam losses at e.g. targets, collimators and beam dumps.
An ideal neutron survey meter for PNF should meet the following requirements:
- Capability to withstand very high instantaneous neutron fluxes with little or no saturation
- Sensitivity comparable to that of commercially available rem counters
- Capability to measure correctly the intensity of a single neutron burst
- Capability to reject the photon contribution that accompanies the field
For the time being there is no device presently capable of fulfilling all the requirements listed above. The QUASAR Group has been investigating the potential use of active proportional counters to be coupled with specifically designed moderators and innovative electronics to deal with very intense and pulsed neutron fields without being affected by saturation effects.