Analyzing Nickel Cross-Sections for Applications in DT Fusion Research​

Background: The fusion of deuterium and tritium is a promising sustainable energy source. Despite recent

breakthroughs at NIF, progress is still needed. One possible diagnostic tool is to use activation foils to search

for any net center-of-mass velocity of the plasma. Since neutrons produced by DT fusion have E_n = 14.1 MeV,

reactions with a strong energy dependence in this range, such as ⁵⁸Ni(n,2n)⁵⁷Ni and ⁵⁸Ni(n,p)⁵⁸Co, can measure

small alterations of the neutron energy.

Purpose: Measuring the production cross-sections of the aforementioned reactions, ⁵⁸Co/⁵⁷Ni, can be used to

reveal insights about the mean neutron energy and velocity of the DT fusion plasma.

Methods: A deuteron beam was created at the TUNL tandem accelerator, which then hit a tritiated target.

Activation foils were placed at varying degrees from incoming deuteron beam. Neutron activation occurred for

10 hours. A HPGe detector was then used to identify the decays of ⁵⁷Ni and ⁵⁸Co. The cross-sections were

calculated.

Results: The cross-sections of the two reactions agree with the evaluations within uncertainty. In addition, the

ratio of cross-sections is reported with reduced uncertainty.

Conclusions: The production cross-sections for ⁵⁷Ni and ⁵⁸Co were measured at four incident neutron energies

around 14.1 MeV. This nuclear data may be used as a possible diagnostic tool for measuring small alterations in

the mean center-of-mass velocity DT plasmas.

This work was supported in part by the U.S. Department of Energy under grant DE-SC0022545.