1971

Construction of the DELTA Laser in Gavett Hall
In 1971, LLE began building DELTA, the first multibeam laser at the Laboratory for Laser Energetics. As a four-beam facility, DELTA had many unique features, including large water-cooled rod amplifiers, superconducting Faraday rotators, cryogenic deuterium targets, frequency conversion to the second harmonic, pulse shaping, and liquid-cooled slab amplifiers.

Fusion by Laser
In June 1971, almost one year after the formal establishment of the Laboratory for Laser Energetics, an article entitled “Fusion by Laser” appeared in Scientific American authored by Moshe J. Lubin (LLE Director at that time) and Arthur P. Frass of Oak Ridge National Laboratory. The summary for this article states: “Experiments indicate that energy-releasing fusion reactions can be initiated, and to some extent, controlled without a confining magnetic field by focusing a powerful laser on a frozen pellet of fuel.”

M. J. Lubin and A. P. Frass, “Fusion by Laser,” Sci. Am. 224 (6), 21–33 (1971).

Laser–Matter Interaction Workshop
At a laser–matter interaction workshop held at Rensselaer Polytechnic Institute (RPI), LLE scientists presented the first results on the use of multiple short laser pulses to enhance absorption of laser light by laser-fusion targets. Multiple-laser-pulse irradiation (pickets) is a feature of current high-gain, direct-drive target designs.