Experimental Assessment of a Flat Sandwich-Like Self-Powered Detector for Nuclear Measurements in ITER Test Blanket Modules

• Published in: IEEE transactions on nuclear science Vol. 65; no. 9; pp. 2385 - 2391
• Main Authors: Raj, Prasoon, Angelone, Maurizio, Doring, Toralf, Eberhardt, Klaus, Fischer, Ulrich, Klix, Axel, Schwengner, Ronald
• Format: Journal Article
• Language: English
• Published: New York IEEE 01.09.2018; The Institute of Electrical and Electronics Engineers, Inc. (IEEE)
• Subjects: Bremsstrahlung; Detectors; Emitters; Fast neutrons; Fluctuations; Flux monitoring; fusion reactors; gamma-ray detection; Geometry; Inductors; Instrumentation; Irradiation; Modules; Monitoring; neutron detection; Neutron flux; Neutrons; Optimization; Photonics; reactor instrumentation; Sensitivity; Thermal neutrons; Vanadium
• ISSN: 0018-9499; 1558-1578
• DOI: 10.1109/TNS.2018.2844554

Neutron and gamma flux measurements in designated positions in the test blanket modules (TBMs) of ITER will be important tasks during its campaigns. Investigations on self-powered detectors (SPDs), a class of reactor flux monitors are undertaken in the framework of an ongoing project on development of nuclear instrumentation for European ITER TBMs. This paper reports the findings of experiments performed with an SPD in flat sandwich-like geometry. A detector with vanadium emitter is chosen for preliminary studies. Its irradiation in a thermal neutron field gives a proof of the principle of flat SPDs. It is further irradiated in the mixed neutron-gamma field of a 14-MeV neutron generator and a bremsstrahlung photon field. The test SPD signals are proportional to the incident fluxes, deeming it suitable for flux monitoring. Whereas both neutrons and gammas can be detected with appropriate optimization of geometries, materials, and sizes of the components, the present design is more sensitive to gammas than fast neutrons. Based on the measured sensitivities of the SPD, its response under TBM conditions is predicted.