A workshop was held at LLE to discuss applications of ultrahigh-power lasers in areas beyond fusion. The assembled panel of experts concluded that there are important applications of these systems: chemistry, biology, equation-of-state studies, effects on materials, and high-energy-density physics.
The National Laser Users Facility (NLUF) was established in 1979 to provide access to LLE’s high-power laser facilities to U.S. scientists. It was the first user facility based on a high-power fusion laser that provides a unique high-energy-density physics experimental facility to this nation’s scientific community. NLUF participants have included scientists from approximately 40 universities, government laboratories, and private companies. NLUF is another aspect of the LLE program that contributes to its unique position among this nation’s ICF laboratories. NLUF serves as a model for the National Ignition Facility users’ programs.
Shown here is the X-ray diffraction pattern of halobacterium halobium taken with sub-nanosecond exposure on the GDL system by Jim Forsyth as part of an early NLUF experiment.
LLE conducted a series of DT implosion experiments on the six-beam ZETA laser with all shots producing yields in excess of 1.5 billion neutrons.
Shown here is ZETA laser target chamber with Bill Watson
U.S. Congressman Frank Horton fired the first shot on ZETA, a laser comprising the first six beams of OMEGA, on 17 October 1978. The shot generated more than 300 million neutrons and climaxed the morning of what University President Robert L. Sproull called a great day in the life of this University. It was witnessed by approximately 200 guests from government, industry, and academia.
Shown here is Congressman Frank Horton
On 7 March 1977, Physical Review Letters published a paper by R. L. McCrory of the Laboratory for Laser Energetics and R. L. Morse of the University of Arizona showing that the efficiency with which absorbed laser energy causes a given spherical implosion increases by a factor of 3 to 5 if the laser wavelength is decreased from the infrared wavelengths to the blue or near-ultraviolet. This finding was key in the thrust to develop high-efficiency frequency conversion for high-power Nd:glass fusion lasers.
Shown here is a scaling of hydrodynamic efficiency from the article, R. L. McCrory and R. L. Morse, “Dependence of Laser-Driven Compression Efficiency on Wavelength,” Phys. Rev. Lett. 38 (10) 544–547 (1977).
The first direct measurement of compressed fuel density in a laser-imploded target using x-ray spectroscopy is reported in a Physical Review Letters article by LLE scientist B. Yaakobi, et al.
Shown here is a compression measurement from the article, B. Yaakobi, D. Steel, E. Thorsos, A. Hauer, and B. Perry, “Direct Measurement of Compression of Laser-Imploded Targets Using X-Ray Spectroscopy,” Phys. Rev. Lett. 39 241526–1529 (1977).
To verify the ability of the original 24-beam OMEGA laser to reach its specified performance level, a one-beam prototype system, GDL (glass development laser), was built in the “new” LLE building in 1977. By 8 November 1977, GDL (right) was producing peak power levels in excess of 0.5 TW per beam in short pulses. GDL continued to operate for a variety of experiments including the first demonstration of high-efficiency frequency tripling, the first comprehensive series of 0.35-µm laser-matter interaction experiments, and the first series of NLUF experiments.
Shown left are Steve Kumpan and Jo Bunkenburg working on rod-amplifier development. Shown below is Bill Lockman, GDL operator, adjusting the pinhole of one of the vacuum spatial filters.
The paper “Laser Compression Studies with Neon-Filled Glass Microballoons” by B. Yaakobi and L. M. Goldman was published in Physical Review Letters. It presented measurements of x-ray emission of compressed neon gas fill in glass microballoons, irradiated by DELTA–an early LLE four-beam laser system.
Several physics packages were added to the one-dimensional hydrodynamic code SUPER: radiation transport, transport of suprathermal electron from resonant absorption and a realistic equation-of-state table. These improvements made possible realistic simulations of implosions carried out on the DELTA Laser System.
Shown here is a comparison of part of the x-ray spectrum from B. Yaakobi and L. M. Goldman, “Laser Compression Studies with Neon-Filled Glass Microballoons,” Phys. Rev. Lett. 37 899–902 (1976).
LLE’s Materials Group led the development of a high-gain phosphate laser glass with a low nonlinear index of refraction for high-power glass laser systems.
Shown here is Steve Jacobs with Dave Segawa and Tsetsuro Izumitani of HOYA Optics
The cornerstone-laying ceremony for the new LLE building took place on 2 April 1976. Guests included representatives of the university, government, and industry. The building was based on architectural design work by United Engineers and engineering design efforts of Eastman Kodak Co. It had 100,000 square feet of laboratory and office space.
Copyright 2002. Univesrity of Rochester. All rights reserved. Department of Rare Books and Special Collections.
Copyright 2002. Univesrity of Rochester. All rights reserved. Department of Rare Books and Special Collections.