Bonner Sphere System with Active Detector for Measurements in Pulsed Neutron Fields

Recent developments in accelerator physics have led to new challenges for radiation protection dosimetry. As is well known, the ambient dose equivalent indicated by area monitors in high-energy neutron fields behind shielding is often unreliable. Therefore, it is desirable to measure the spectrum and to do "in-field" calibrations using the spectral information as reference. For this purpose, the PTB NEMUS (an extended-range Bonner sphere spectrometer) was modified with a new active thermal neutron detector based on silver activation capable of measuring in intense pulsed fields with high energies and fluence rates.