Developing stagnating-corona fusion targets as neutron sources

We describe the development of an `inverted-corona' fusion platform for neutron generation. Spherical, low-Z targets with either an inner CD layer, or filled with fusionable gas (D2 or DT) are irradiated on the inside surface via laser beams entering through laser-entrance holes. The resulting ablative flow reaches high velocities, 1000 km/s, before interacting at the target's center. This generates fusion reactions through stagnation and thermalization of the fast ions. This platform has been demonstrated at the kJ-level [1,2], and is expected to scale to intermediate neutron yields in excess of 1e14 at moderate laser energies (hundred-kJ level), while offering advantages over conventional, laser-driven neutron sources. For example, substantial neutron fluences at the target wall make it an interesting platform for basic science applications, while the potential for single-sided drive of the neutron source make it ideal for neutron radiography. We will present results from proof-of-principle experiments on OMEGA and design calculations for NIF-scale targets. Prepared by LLNL under Contract DE-AC52-07NA27344. [1] Ren et al., Phys. Rev. Lett. 118, 165001 (2017) [2] Abe et al., Appl. Phys. Lett. 111, 233506 (2017)