Neutron imaging estimation of nuclear radchem diagnostics

Nuclear reactions induced by neutrons are utilized ubiquitously as diagnostics in fusion plasma experiments. By doping the contained plasma (or its boundary) with elements which are susceptible to various neutron-induced reactions, one can extract information about the burn by measuring the isotopes produced in threshold reactions such as (n,2n) neutron knock-out, and zero-threshold reactions such as (n,γ) neutron capture. At the National Ignition Facility (NIF), three-dimensional reconstructions of the (time-integrated) fusion burn are obtained using neutron imaging. By utilizing this data, we can estimate local densities and neutron fluences, thereby allowing us to further estimate the total number of induced reactions for each of the diagnostics of interest. We can then compare these estimates with the experimentally obtained isotope counts. In this presentation, we will illustrate this technique as well as provide explicit comparison with experimentally measured reaction products.