Shiva laser
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The Shiva laser was an extremely powerful 20 beam infrared neodymium glass (silica glass) laser built at Lawrence Livermore National Laboratory in 1977 for the study of inertial confinement fusion and long-scale-length laser-plasma interactions. It was capable of delivering a ~.5 to 1 nanosecond pulse of approxametly 10.2 kilojoules of infrared light at 1.062 micrometres (μm) wavelength (thus achieving a peak power of ~20 terawatts) to a target and ultimately achieved fusion fuel compression to densities of about 50 to 100 times liquid hydrogen density. The Shiva laser provided the highest power, highest energy on target and highest fuel compression of any laser up until its successor the Nova laser though, due to the fact that it used such a long wavelength of light for target compression (unlike its frequency doubled and frequency tripled sucessors), target compression and heating was hampered by the production of hot (high kinetic energy) electrons which allowed the hydrogen and deuterium ions to remain relatively cool. John Holzrichter, director of the ICF program at the time said: "The laser beam generates a dense plasma where it impinges on the target material. The laser light gives up its energy to the electrons in the plasma, which absorb the light. The rate at which that happens depends on the wavelength and the intensity. On Shiva, we were heating up electrons to incredible energies, but the targets were not performing well. We tried a lot of stuff to coax the electrons to transfer more of their energy to the target, with no success". The Shiva target chamber utilized high-resolution, high-speed optical and x-ray diagnostic instruments for the characterization of the hot, dense plasmas created during implosion. Shiva was decomissioned in 1981.
See also
External links
- [A movie of the Shiva laser system showing beamlines and target chamber]
- [Details of the Shiva laser system and achievements]
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