Neutron diagnosis of compressed ICF targets

The final stages in the compression of microencapsulated DT fueled ICF targets require detailed characterization for meaningful comparison with predictions of hydrodynamic codes. The determination of such parameters as the fuel and shell areal densities, the average ion temperature, and the impact of implosion nonuniformities in high-density target implosions present a strong challenge. We describe several approaches utilizing the self-generated neutrons to diagnose these conditions, including neutron spectrometry, neutron activation of tracer gas and shell materials, and neutron scattering techniques. The importance of making simultaneous measurements of several core parameters to limit ambiguity in interpretation is discussed.