Comparing neutron and X-ray images from NIF implosions

D.C. Wilson, R.J. Aragonez, T.N. Archuleta, D.P. Atkinson, M.A. Barrios, S.H. Batha, D.E. Bower, D.K. Bradley, R.A. Buckles, D.D. Clark, D.S. Clark, D.J. Clark (+61 others)
2013 EPJ Web of Conferences  
Directly laser driven and X-radiation driven DT filled capsules differ in the relationship between neutron and X-ray images. Shot N110217, a directly driven DT-filled glass micro-balloon provided the first neutron images at the National Ignition Facility. As seen in implosions on the Omega laser, the neutron image can be enclosed inside time integrated X-ray images. HYDRA simulations show the X-ray image is dominated by emission from the hot glass shell while the neutron image arises from the
more » ... e arises from the DT fuel it encloses. In the absence of mix or jetting, X-ray images of a cryogenically layered THD fuel capsule should be dominated by emission from the hydrogen rather than the cooler plastic shell that is separated from the hot core by cold DT fuel. This cool, dense DT, invisible in X-ray emission, shows itself by scattering hot core neutrons. Germanium X-ray emission spectra and Ross pair filtered X-ray energy resolved images suggest that germanium doped plastic emits in the torus shaped hot spot, probably reducing the neutron yield. Soon after the first laboratory neutron images of inertial confinement fusion (ICF) capsules were obtained [1], their physical interpretation has included comparison in size and shape with X-ray images [2] . Christensen et al. [3] carried out experiments on the Omega laser [4] with controlled asymmetry and compared the calculated and observed X-ray and neutron images. Wilson et al. [5] used these same implosions to study mix between the glass shell and DT fuel. In this paper we report the first comparison of neutron and X-ray images from both directly and radiation driven implosions on the National Ignition Facility Laser [6] . Fundamentally the X-ray and neutron emissions from an imploding ICF capsule have different sources. Neutron emission comes from regions of high D + T neutron production, i.e. high D and T ion This is an Open Access article distributed under the terms of the Creative Commons Attribution License 2.0, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.
doi:10.1051/epjconf/20135904002 fatcat:ijaewmybpnextbuv6uvgyuyvym