Dale B. Henderson

Spatial distribution of ionization in electron‐beam‐controlled discharge lasers

We explore the uniformity of energy deposition from the primary (ionizing) beam from the electron‐beam‐controlled discharge laser, especially considering the magnetic deflections and the scattering collisions. We find the addition of a parallel guide magnetic field to be useful.

Re-examination of strongly flux limited thermal conduction in laser produced plasmas

Laser interaction experiments on plastic foils at 1.06 μm and 10.6 μm wavelengths have been re‐examined using the LASNEX hydrodynamics code modified to include ponderomotive force effects and realistic hot electron generation. The data for a wide range of experiments have been accurately modeled without invoking an anomalous limit on the electron heat flux.

Electron transport in gas discharge lasers

We have developed a set of computer codes to treat the transport of the high‐energy (primary) electrons in gas discharge lasers of the Los Alamos type. Such electron transport requires no new physical ideas, but must be applied without any of the common restrictions. In contrast to existing theory, we may not specialize to total turning without energy loss; we may not specialize to energy loss without turning or tortuous paths; we are interested in observations other than just those made far from the interaction region; and we must include applied electric and magnetic fields. Our codes meet these requirements and still permit the computation of cases of interesting complexity with the investment of a modest amount of machine time. Several examples are reported as verification of the computation and as its application to laser design.

Symmetry of Laser-Driven Implosions

A perturbation method is developed for nearly spherical heat and fluid flow. It shows that electron thermal conduction may be sufficiently symmetrizing to allow laser-driven fusion with a single beam.

Pulse unfocusing within laser-fusion reactors

Abstract Most serious laser-fusion reactor studies involve an atmosphere of lithium vapor within the pulse cavity. The laser pulse ionizes the vapor, generating an ‘unfocusing’ refractive medium. Proper account of this effect may necessitate a lower vapor density than previously reported.

Systems Modeling At Los Alamos

Because of the needs of nuclear weapons development, Los Alamos has been a leader in physics-based computer modeling throughout its fifty-year history. Over the last decade we have developed detailed large-scale systems-level finite-event simulations, including people, for military engagements and campaigns. We have independently pioneered many object- oriented techniques. Our current research emphasizes simulations composed of intelligent actors. One current prototype activity is building a simulation of health care at the individual person level for the State of New Mexico. We are eager to share our extensive experience, methods and capabilities with the health care community.

Use of Radioactive Test Ions in the Measurement of the Spatial Distribution of Plasma Ion Drift Speeds

Radioactive test ions have been used to measure the axial ion drift speed distribution in a single‐ended Q machine. In the main plasma region these drift speeds are found to be significantly smaller than predicted by the sheath model.