Nuclear Reactions Suitable For Epithermal Neutron Dosimetry Using Boron-Based Filters: Preparation Of An Experimental Campaign At The Jsi Triga Reactor

Activation measurements, the primary method of determination of the neutron fluence, are generally sensitive to the thermal and resonance energy ranges (neutron capture reactions) and the fast energy range (threshold reactions). However, there are very few nuclear reactions which are sensitive specifically to neutrons in the intermediate (epithermal) energy region. In recent work, conducted in the framework of a research collaboration project between the French Atomic and Alternative Energy Commission (CEA) and the Jozef Stefan Institute (JSI), Slovenia, indications were obtained that boron-based neutron filter materials, due to the very large magnitude and almost pure 1/v energy dependence of the B-10 absorption cross-section, are able to shift significantly the sensitivity of neutron capture reactions towards the epithermal energy range. A new collaboration project between the CEA and the JSI was launched to perform a broad investigation of neutron capture reactions in combination with boron-based neutron filters of different geometry, material and isotopic composition (i.e. B-10 enrichment level) could be suitable for measurements of the epithermal neutron flux, in terms of their energy sensitivity and in terms of the possibility of gamma spectrometry measurements of the reaction products. This paper presents the preparation process of a dedicated experimental campaign, to be performed November 2018 in the JSI TRIGA reactor.