This volume of the LLE Review, covering October–December 2007, features a report on target experiments using the Multi-Terawatt (MTW) Laser Facility to study the isochoric (constant volume) heating of solid-density targets by electrons produced from intense, short-pulse laser irradiation. Electron refluxing occurs due to target-sheath field effects and contains most of the fast electrons within the target volume. This efficiently heats the solid-density plasma through collisions. X-ray spectroscopic measurements indicate that laser energy couples to fast electrons with a conversion efficiency of ~20%. Bulk electron temperatures of at least 200 eV are inferred for the smallest mass targets.
Additional highlights of research presented in this issue include the following:
- The design of a high-resolution optical transition-radiation diagnostic for fast-electron-transport studies using the MTW facility.
- The performance of direct-drive cryogenic target implosions is analyzed.
- Results of initial implosion experiments to study shock-ignition inertial confinement fusion target concepts are discussed.
- Time-resolved absorption measurements in cryogenic as well as room-temperature, direct-drive OMEGA implosions are presented.
- A report is included on monoergetic proton radiography of electromagnetic field and particle density distributions in ICF target implosions.