Beams of fully stripped nitrogen ions have been used to investigate the behavior of the double-to-single ionization cross-section ratio of helium in the 10-30-MeV/amu velocity region. The measured ratio was found to remain nearly constant over this velocity range at a value of 0.01, which is about 4.5 times higher than the high-velocity limit established previously for q = 1 projectiles.

No abstract

We describe a radiochemical measurement of the ratio of isotope concentrations produced in a gold hohlraum surrounding an Inertial Confinement Fusion capsule at the National Ignition Facility (NIF). We relate the ratio of the concentrations of (n,γ) and (n,2n) products in the gold hohlraum matrix to the down-scatter of neutrons in the compressed fuel and, consequently, to the fuel's areal density. The observed ratio of the concentrations of (198m+g)Au and (196g)Au is a performance signature of ablator areal density and the fuel assembly confinement time. We identify the measurement of nuclear cross sections of astrophysical importance as a potential application of the neutrons generated at the NIF.

No abstract

All of the neutron generators developed in the Plasma and Ion Source Technology Group are utilizing powerful RF-induction discharge to generate the deuterium plasma. One of the advantages of using the RF-induction discharge is it's ability to generate high fraction of atomic ions from molecular gases, and the ability to generate high plasma densities for high extractable ion current from relatively small discharge volume. Figure 1. Schematic drawing of the co-axial neutron generator on the left, the co-axial neutron generator on the right. SHIELDING STRUCTURE NEUTRON GENERATOR