Neutronics diagnostics for European ITER TBMs: Activation foil spectrometer for short measurement cycles

Testing of tritium breeder blanket activation foil spectrometer during JET operations

“…A set of suitable dosimetry reactions were proposed for use in a TBM foil-based spectrometry system [5], a subset of which can be seen in Table 1, using criteria such as intensity and number of emitted gamma lines and half-life. The proposed short half-life reactions cover a range of energy threshold and non-threshold reactions and require a limited number of different high-purity foils that will be compatible with the environmental conditions expected of the ITER TBMs.…”

“…Thinner foils are proposed for testing in future D-T operations, but for testing and validation of associated processes in D-D conditions, and bearing in mind the detection limits, these thicker foils were needed. Although Ce foils were proposed in [5], investigations regarding the suitability of the material for irradiation under the JET D-D environment deemed the material unsuitable in its elemental form.…”

Optimising Foil Selection for Neutron Activation Systems

“…However knowledge of the first wall spectrum is essential for monitoring the power output of the fusion reactor [5], predicting its tritium breeding ratio [6], inferring the radiation damage to the structural components, validating the radiation transport models for shielding components [7], as well as supplementing the plasma parameter measurements [8]. Many of these activities are critical to the safety, sustainability, and viability of fusion as a commercial energy source.…”

“…However, the technique of neutron-spectrum unfolding using activation foils requires optimisation for measuring fusion neutron spectra. Previous investigations have only selected foils on an ad hoc basis (see [5,6,9] for example). In this paper, a programmatic approach to foil selection is shown to increase the precision provided by neutron activation systems.…”