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Bayramian, A

Publications and source records attributed to Bayramian, A.

Laser System for Livermore's Mono Energetic Gamma-Ray Source

A Mono-energetic Gamma-ray (MEGa-ray) source, based on Compton scattering of a high-intensity laser beam off a highly relativistic electron beam, requires highly specialized laser systems. To minimize the bandwidth of the {gamma}-ray beam, the scattering laser must have minimal bandwidth, but also match the electron beam depth of focus in length. This requires a {approx}1 J, 10 ps, fourier-transform-limited laser system. Also required is a high-brightness electron beam, best provided by a photoinjector. This electron source requires a second laser system with stringent requirements on the beam including flat transverse and longitudinal profiles and fast rise times. Furthermore, these systems must be synchronized to each other with ps-scale accuracy. Using a novel hyper-dispersion compressor configuration and advanced fiber amplifiers and diode-pumped Nd:YAG amplifiers, we have designed laser systems that meet these challenges for the X-band photoinjector and Compton-scattering source being built at Lawrence Livermore National Laboratory.

42 ENGINEERING↗

Improved Characterization of Transmitted Wavefront Error on CADB Epoxy-Free Bonded Solid State Laser Materials

Current state-of-the-art and next generation laser systems - such as those used in the NIF and LIFE experiments at LLNL - depend on ever larger optical elements. The need for wide aperture optics that are tolerant of high power has placed many demands on material growers for such diverse materials as crystalline sapphire, quartz, and laser host materials. For such materials, it is either prohibitively expensive or even physically impossible to fabricate monolithic pieces with the required size. In these cases, it is preferable to optically bond two or more elements together with a technique such as Chemically Activated Direct Bonding (CADB{copyright}). CADB is an epoxy-free bonding method that produces bulk-strength bonded samples with negligible optical loss and excellent environmental robustness. The authors have demonstrated CADB for a variety of different laser glasses and crystals. For this project, they will bond quartz samples together to determine the suitability of the resulting assemblies for large aperture high power laser optics. The assemblies will be evaluated in terms of their transmitted wavefront error, and other optical properties.

42 ENGINEERING↗

Compton Scattering Sources and Applications at LLNL

We report the design and current status of a monoenergetic laser-based Compton scattering 0.5-2.5 MeV {gamma}-ray source. Previous nuclear resonance fluorescence results and future linac and laser developments for the source are presented.

43 PARTICLE ACCELERATORS↗