Preliminary Experimental Test of Activation Foil Materials with Short Half-Lives for Neutron Spectrum Measurements in the ITER TBM

We have performed preliminary experimental tests for the development of a neutron spectrometer based on activation foils with short half-lives for the European ITER TBMs. Small samples of candidate materials have been irradiated with DT neutrons from the neutron generator of Technical University of Dresden. A dedicated pneumatic sample transport system has been set up for these initial tests and further development of methods for spectral neutron flux measurements in the TBM. The mass of the samples was on the order of 0.6 g. Although the neutron flux in the irradiation position of the samples was three to five orders of magnitude below the expected flux in the TBM at full DT operation of ITER, it was possible with short irradiation time of 60 s and similar gamma-ray measurement times to obtain the induced activity with moderate uncertainty.