W. Stoeffl

The experimental plan for cryogenic layered target implosions on the National Ignition Facility—The inertial confinement approach to fusion

Ignition requires precisely controlled, high convergence implosions to assemble a dense shell of deuterium-tritium (DT) fuel with ρR>∼1 g/cm2 surrounding a 10 keV hot spot with ρR ∼ 0.3 g/cm2. A working definition of ignition has been a yield of ∼1 MJ. At this yield the α-particle energy deposited in the fuel would have been ∼200 kJ, which is already ∼10 × more than the kinetic energy of a typical implosion. The National Ignition Campaign includes low yield implosions with dudded fuel layers to study and optimize the hydrodynamic assembly of the fuel in a diagnostics rich environment. The fuel is a mixture of tritium-hydrogen-deuterium (THD) with a density equivalent to DT. The fraction of D can be adjusted to control the neutron yield. Yields of ∼1014−15 14 MeV (primary) neutrons are adequate to diagnose the hot spot as well as the dense fuel properties via down scattering of the primary neutrons. X-ray imaging diagnostics can function in this low yield environment providing additional information about ...

An Improved RF Cavity Search for Halo Axions

The axion is a hypothetical elementary particle and cold dark matter candidate. In this RF cavity experiment, halo axions entering a resonant cavity immersed in a static magnetic field convert into microwave photons, with the resulting photons detected by a low-noise receiver. The ADMX Collaboration presents new limits on the axion-to-photon coupling and local axion dark matter halo mass density from a RF cavity axion search in the axion mass range 1.9-2.3 {micro}eV, broadening the search range to 1.9-3.3 {micro}eV. In addition, we report first results from an improved analysis technique.

Results from a High-Sensitivity Search for Cosmic Axions

We report the first results of a high-sensitivity

New Organic Crystals for Pulse Shape Discrimination

(\ensuremath{\sim}{10}^{\ensuremath{-}23}\mathrm{W})

The National Ignition Facility neutron time-of-flight system and its initial performance (invited)a)

search for light halo axions through their conversion to microwave photons. At the 90% confidence level, we exclude a Kim-Shifman-Vainshtein-Zakharov axion of mass

Experimental Constraints on the Axion Dark Matter Halo Density

2.9\ifmmode\times\else\texttimes\fi{}{10}^{\ensuremath{-}6}

Diagnosing inertial confinement fusion gamma ray physics (invited).

to

Development of the CD Symcap platform to study gas-shell mix in implosions at the National Ignition Facility

3.3\ifmmode\times\else\texttimes\fi{}{10}^{\ensuremath{-}6}\mathrm{eV}

ICF gamma-ray reaction history diagnostics

as the dark matter in the halo of our galaxy.

Gamma bang time/reaction history diagnostics for the National Ignition Facility using 90° off-axis parabolic mirrorsa)

Efficient, readily-available, low-cost, high-energy neutron detectors can play a central role in detecting illicit nuclear weapons since neutrons are a strong indication for the presence of fissile material such as Plutonium and Highly-Enriched Uranium. The main challenge in detecting fast neutrons consists in the discrimination of the signal from the gamma radiation background. At present, the only well-investigated organic crystal scintillator for fast neutron detection, in a n/gamma mixed field, is stilbene, which while offering good pulse shape discrimination, is not widely used because of its limited availability and high cost.