We describe an improvement of the neutron activation system in operation on the Frascati Tokamak Upgrade (FTU) tokamak for the measurement of the total neutron yield. A HPGe well-type detector (200 cm3active volume) is used to detect the photoemission from neutron activated samples (115mIn 336.2 keV γ rays from DD neutrons on indium for FTU). Due to their high geometrical efficiency, HPGe well-type detectors are particularly suited to the FTU low-level activity measurements. A particular effort has been devoted to the calibration of the measuring system. In particular, a multi-γ calibration source (59-1332 keV energy range) with a density of 7.31 g/cm3consisting of a stack of indium foils has been prepared. This assures that the shape and volume of the calibration source are the same as those of the samples used in the actual measurements. The full-energy-peak efficiency at the115mIn 336.2 keV line is 0.197 with an overall uncertainty of 2% (1σ). For a better characterization of the detector response as a function of the sample density, a further calibration source with the same geometry has been prepared in a gel aqueous solution (density ∼1 g/cm3). The calibration curves for the well-type detector at the two different density values are compared. © 1997 American Institute of Physics.
All Science Journal Classification (ASJC) codes
Bertalot, L., Damiani, M., Esposito, B., Lagamba, L., Podda, S., Batistoni, P., ... Biagini, R. (1997). HPGe well-type detectors for neutron activation measurements on the Frascati Tokamak Upgrade tokamak. Review of Scientific Instruments, 68(1), 528 - 531. https://doi.org/10.1063/1.1147621