LLE Annual Report

2002

Annual Report 2002

The LLE 2002 Annual Report is an account of the Laboratory’s work during FY02 under Cooperative Agreement DE-FC03-92SD19460 with the Department of Energy (DOE). The report summarizes the progress made by the Laboratory for Laser Energetics (LLE) in the following areas: inertial confinement fusion (ICF) research; work in support of the Stockpile Stewardship Program (SSP); laser and optical materials research; advanced technology development; operation of the OMEGA facility; the National Laser Users’ Facility (NLUF), and external users’ programs; and several educational initiatives ranging from a high school student research program to advanced graduate education and research.

A focus of this year’s ICF research program was cryogenic target implosion experiments on OMEGA. These experiments comprise the scientific research base leading to direct-drive-ignition implosions planned for the National Ignition Facility (NIF). The initial results of these experiments, including measurements of primary fusion yield as well as secondary proton and neutron yield, burn history, and x-ray imaging, are described in this report. The results are encouraging for future cryogenic implosions on both OMEGA and the NIF. Significant advances in fusion target fabrication technology and science underpin the cryogenic target implosion effort. Several accounts are offered in this report on the progress made in the fabrication, characterization, and experimental implementation of cryogenic targets on OMEGA, including polyimide shell fabrication, development of the requisite tritium handling and recovery systems, and cryogenic target characterization.

Experiments that control all aspects of nonuniformities in target manufacture, irradiation, and precision direct-drive conditions are required to prepare for direct-drive ignition on the NIF. Recent experiments with warm (i.e., gas-filled) targets on OMEGA tested the ability of the laser pulse shape (using a “picket” pulse) to vary the adiabat within an imploding direct-drive capsule. This approach is deemed critical to the demonstration of direct-drive ignition on the NIF.

In addition to accounts of the progress made in the Laboratory’s primary research and development areas, this report also includes a summary of experiments conducted on OMEGA by teams of scientists from other universities, private industry, and government laboratories including Lawrence Livermore National Laboratory (LLNL), Los Alamos National Laboratory (LANL), and Sandia National Laboratory (SNL). Approximately half of the record 1428 target shots taken on OMEGA in FY02 were devoted to external users of OMEGA.

Finally, the report includes a summary of the LLE education programs in FY02. LLE is the only major university participant in the National ICF Program, and education is an important mission for the Laboratory.

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