LLE Annual Report

2003

Annual Report 2003

The fiscal year ending September 2003 concluded the first year of the second five-year renewal of cooperative agreement DE-FC03-92SF19460 with the U.S. Department of Energy (DOE). This report summarizes research at the Laboratory for Laser Energetics (LLE) conducted during the year, the operation of the National Laser Users’ Facility (NLUF), the status of the new OMEGA Extended Performance (EP) laser project, and programs concerning the education of high school, undergraduate, and graduate students during the year.

The prime thrust of LLE’s ICF research is the validation of capsule designs that are hydrodynamically equivalent to the baseline cryogenic direct-drive-ignition design for the National Ignition Facility (NIF). In FY03, neutron yields were measured on OMEGA from cryogenic capsules, with high-adiabat drive pulses, that were close to those calculated by 1-D hydrocodes. Near-2-D hydrocode performance was measured on similar capsules with low-adiabat drive pulses. Improved direct-drive capsule performance was demonstrated using adiabat shaping with a high-intensity picket pulse in front of the main-drive pulse. The report also contains an account of the seminal work to experimentally validate the reduction in the Rayleigh–Taylor growth rate using a picket pulse in planar-target experiments. The results suggest that the acceleration-phase RT growth rates for short-wavelength, laser-induced imprint perturbations may be virtually eliminated by using such picket pulses. Other related work reported in this volume includes “polar direct drive” (PDD)—a new topic of research this year—which examines the feasibility of using the x-ray-drive configuration at the NIF to achieve direct-drive ignition and work target fabrication, characterization, and experimental implementation of cryogenic targets on OMEGA. These results are all key to the early demonstration of ignition with cryogenic direct-drive capsules on the NIF.

Progress on the OMEGA EP project is also reported in this volume. Initial funding, NNSA approval of “Mission Need,” University of Rochester authorization of funding for the building construction, NNSA decision to proceed with the design and construction of the first two beams of the EP system, and start of building construction all occurred during FY03. OMEGA EP will couple short-pulse technology with the 60-beam compression facility by the end of FY07. This project will modernize OMEGA and significantly expand the range of high-energy-density (HED) physics experiments carried out during the second half of this decade and beyond.

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), More than half of the total target shots on OMEGA during FY03 were dedicated to these external users.

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 of the Laboratory.

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