Inertial Confinement Fusion: An Introduction; The Energy of the Stars

vi, 62 pages. Illustrations (some in color). Inertial confinement fusion (ICF) is a type of fusion energy research that attempts to initiate nuclear fusion reactions by heating and compressing a fuel target, typically in the form of a pellet that most often contains a mixture of deuterium and tritium. To compress and heat the fuel, energy is delivered to the outer layer of the target using high-energy beams of laser light, electrons or ions. The heated outer layer explodes outward, producing a reaction force against the remainder of the target, accelerating it inwards, compressing the target. This process is designed to create shock waves that travel inward through the target. A sufficiently powerful set of shock waves can compress and heat the fuel at the center so much that fusion reactions occur. The energy released by these reactions will then heat the surrounding fuel, and if the heating is strong enough this could also begin to undergo fusion. The aim of ICF is to produce a condition known as ignition, where this heating process causes a chain reaction that burns a significant portion of the fuel. In practice, only a small proportion of this fuel will undergo fusion, but if all this fuel were consumed it would release the energy equivalent to burning a barrel of oil. ICF is one of two major branches of fusion energy research, the other being magnetic confinement fusion. The largest operational ICF experiment is the National Ignition Facility (NIF) in the US. As of October 7, 2013, this facility is understood to have achieved for the first time a fuel capsule that gave off more energy than was applied to it. The Laboratory for Laser Energetics (LLE) is a scientific research facility which is part of the University of Rochester's south campus, located in Brighton, New York. The lab was established in 1970 and its operations since then have been funded jointly; mainly by the United States Department of Energy, the University of Rochester and the New York State government. The Laser Lab was commissioned to serve as a center for investigations of high-energy physics, specifically those involving the interaction of extremely intense laser radiation with matter. Many types of scientific experiments are performed at the facility with a strong emphasis on inertial confinement, direct drive, laser-induced fusion using OMEGA, currently the world's highest-energy ultraviolet laser. The lab shares its building with the Center for Optoelectronics and Imaging and the Center for Optics Manufacturing. A new addition, the Robert L. Sproull Center for Ultra High Intensity Laser Research, was opened in 2005 and houses the OMEGA EP laser, which was completed in May 2008. The laboratory is unique in conducting big science on a university campus. More than 180 Ph.D.s have been awarded for research done at the LLE. During summer months the lab sponsors a program for high school students which involves local-area high school juniors in the research being done at the laboratory. Most of the projects are done on current research that is led by senior scientists at the lab. The LLE was founded on the University of Rochester's campus in 1970, by Dr. Moshe Lubin. Working with outside companies such as Kodak the team built Delta, a four beam laser system in 1972. Construction started on the current LLE site in 1976.[4] The facility opened in 1978 a six beam laser systems and a 24 beam system follows two years later. In 1985, Donna Strickland and Gérard Mourou invent a method to amplify lasers pulses by "chirping". This method change a single wavelength of laser light into a spectrum of wavelengths. The system amplifies the laser at each wavelength and then reconstitutes the beam into one color. Chirp pulsed amplification became instrumental in building the National Ignition Facility and the Omega EP system. In 1995, the omega laser was increased to 60 beams system and in 2008 the Omega extended performance system was opened. The OMEGA laser at the LLE.