Cryomilling of Isotope-Enriched Ti Powders for HIVIPP Deposition to Manufacture Targets for Nuclear Cross Section Measurement.

The realization of isotopically enriched Ti targets for nuclear cross-section measurements requires particular attention, from the starting material preparation up to the deposition technique. In this work, a cryomilling process was developed and optimized, aimed at reducing the size of 49,50 Ti metal sponge as provided by the supplier (size up to 3 mm), to the optimal size of 10 µm, to fit the High Energy Vibrational Powder Plating technique used for target manufacturing. The optimization of the cryomilling protocol and the HIVIPP deposition using nat Ti material was thus performed. The scarce amount of the enriched material to be treated (about 150 mg), the need to obtain a non-contaminated final powder and a uniform target thickness of about 500 µg/cm 2 were taken into account. The 49,50 Ti materials were then processed and 20 targets of each isotope were manufactured. Both powders and the final Ti targets produced were characterized by SEM-EDS analysis. The amount of Ti deposited was measured by weighing, indicating reproducible and homogeneous targets, with an areal density of 468 ± 110 µg/cm 2 for 49 Ti ( n = 20) and 638 ± 200 µg/cm 2 for 50 Ti ( n = 20). The uniformity of the deposited layer was also confirmed by the metallurgical interface analysis. The final targets were used for the cross section measurements of the 49 Ti( p ,x) 47 Sc and 50 Ti( p ,x) 47 Sc nuclear reaction routes aimed at the production of the theranostic radionuclide 47 Sc.