Direct Determination of Fission-Barrier Heights Using Light-Ion Transfer in Inverse Kinematics

We demonstrate a new technique for obtaining fission data for nuclei away from <math display="inline"><mi>β</mi></math> stability. These types of data are pertinent to the astrophysical <math display="inline"><mrow><mi>r</mi></mrow></math> process, crucial to a complete understanding of the origin of the heavy elements, and for developing a predictive model of fission. These data are also important considerations for terrestrial applications related to power generation and safeguarding. Experimentally, such data are scarce due to the difficulties in producing the actinide targets of interest. The solenoidal-spectrometer technique, commonly used to study nucleon-transfer reactions in inverse kinematics, has been applied to the case of transfer-induced fission as a means to deduce the fission-barrier height, among other variables. The fission-barrier height of <math display="inline"><mrow><mmultiscripts><mrow><mi mathvariant="normal">U</mi></mrow><mprescripts/><none/><mrow><mn>239</mn></mrow></mmultiscripts></mrow></math> has been determined via the <math display="inline"><mrow><mmultiscripts><mrow><mi mathvariant="normal">U</mi></mrow><mprescripts/><none/><mrow><mn>238</mn></mrow></mmultiscripts><mo stretchy="false">(</mo><mi>d</mi><mo>,</mo><mi>p</mi><mi>f</mi><mo stretchy="false">)</mo></mrow></math> reaction in inverse kinematics, the results of which are consistent with existing neutron-induced fission data indicating the validity of the technique.