230U Yield Measurement on 3,4He-Irradiated ThO2 Targets

The 230 U yield in the direct reactions 232 Th( 3 He, 5 n ) 230 U and 232 Th( 4 He, 6 n ) 230 U on thick ThO 2 targets irradiated by 65 and 55 MeV nuclei 3,4 He was measured and compared with calculations. The experimental yield of 230 U in the reaction 232 Th( 3 He, 5 n ) 230 U is approximately 10 times higher than the value computed using the constants from TENDL-2019. The experimental yield of 230 U in the reaction 232 Th( 4 He, 6 n ) 230 U the same, to within t5he limits of error, as the computed value. Comparing the experimental and computed yield in the reaction 232 Th( 4 He, 6 n ) 230 U with the cross section obtained by the ALICA program (USA) showed that the computed cross section is incorrect and the prognoses for 230 U production based on it are unsubstantiated. It is concluded that the reactions 232 Th( 3 He, 5 n ) 230 U and 232 Th( 4 He, 6 n ) 230 U are inefficient for 230 U production in the U-150 cyclotron at the NRC Kurchatov Institute in amounts required for clinical applications.