Improvement of thickness and uniformity of isotopically enriched 12C targets on backings by the HIVIPP method

We have made enriched 12C targets to accurately measure the cross-section of the 12C(α,γ)16O reaction, which is very important in nuclear astrophysics. Isotopically enriched 12C targets for studying this small cross-section, especially for use with an intense pulsed α beam was desired to meet the following requirements: (1) use of impurity-free enriched 12C, (2) stability for a long time measurement and (3) uniform thickness in the range 200–300 μg/cm2. To meet these experimental requirements, isotopically enriched amorphous 12C powder was converted into graphite powder in an electric furnace at a temperature of 3000 K and subsequently the graphite powder was deposited on a thick Au backing via the HIVIPP method. Targets thus prepared could be made thicker than 200 μg/cm2. They had a good uniformity and a very high stability against irradiation with high intensity ion beams.