Hohlraum case houses the fuel needed for fusion (via LLNL)
Scientists have been looking to create the power of the sun down here on earth and find a way to harness that energy since the 1920’s. The processes in doing so have been a long and laborious process that has usually resulted in a slew of disappointments over the decades, however the Lawrence Livermore National Laboratory has finally gained some ground in making nuclear fusion power a reality. Nuclear fusion is a nuclear reaction that was derived from smashing two atomic nuclei together at incredible speeds, which form a new type of atomic nucleus. There are several methods at achieving this type of reaction, including thermonuclear fusion, inertial confinement fusion and beam-beam/beam-target fusion.
While we already know that thermonuclear fusion yields large amounts of useful (albeit deadly and destructive) there really is no practical way to harness that expended energy, which is why scientists at the LLNL turned to the inertial confinement version, which hasn’t been very promising till now. The ICF method is attempted by both heating and compressing a fuel target, typically in the form of a pellet comprised of deuterium and tritium. The process of igniting that fuel usually involves high-powered laser beams aimed at the outer layer of the target, which explodes outwards, where it then produces a reaction force against what’s left of the target pellet. That force accelerates inwards thereby compressing the target pellet, which creates shockwaves that further heat and compress the center of the target so much so that a fusion reaction occurs. The aim of this process is to achieve ‘ignition’, whereby the heating process results in a chain reaction that burns most all of the target fuel, resulting in more energy released than what was required to get a fusion reaction. Simply put, they want to spend less energy to gain significantly more in the process. Over the last few years, the scientists at LLNL have made little progress in getting that fuel to sustain a reaction using their $5-billion facility, which is outfitted with 192 IR lasers capable of firing off 500-trillian watts of unbridled power in one extreme shot! That’s a lot of juice but it hasn’t, until now, been enough to create an ignition.
The Lab recently reported that on two occasions, one in September and November of last year, they were able to successfully achieve fusion reactions using hydrogen with more power generated than what was used. To accomplish this feat, the team alternated the laser pulse as to not break up the plastic shell that encapsulates the pellet (which is smaller than a peppercorn in size) as it undergoes the compression state. While that is a crucial step forward in sustaining a fusion reaction that yields larger amounts of energy with minimal input, only 1% of the laser power was successful at getting through to produce that reaction, which is wholly inefficient for achieving that sustainment. Still, the experiments show that laser-fusion is a real possibility and one worthy of continued exploration.
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