With all the talk of green energy alternatives, we know our greatest hope for sustainability is no longer drilling holes for oil or decapitating mountains for “clean coal“. Yes, solar, wind, wave, geo-thermal, conservation and recycling are all critical. But there is a larger need, a voracious appetite for energy that will require large output facilities. Traditional nuclear is not the answer. The poison seed we are planting in the desert will be our 10,000 year legacy. A legacy made worse by importing other nations nuclear waste. The hope for mankind’s energy needs in the 21st century is controlled thermonuclear fusion and at $3.9 billion (GAO est.), that is exactly what the National Ignition Facility (NIF) is built to do.
The National Ignition Facility (NIF) is the world’s largest laser. It was built with the goal of studying the conditions needed to create controlled nuclear fusion on earth (the process our sun uses to generate energy). It is hoped that humanity is finally on the verge of unlocking the secrets of galactic grade power. This would provide clean, limitless energy for all. At least that is the hope. The steps necessary to get here have been herculean. On May 29th, 2009 we opened the star power business.
“The facility was dedicated today (May 29) at a ceremony attended by numerous state and national officials.”World’s largest laser opens | May 29th, 2009 By Andy Evangelista physorg.com
Creating star energy in a controlled environment with nuclear fusion can be seen as the opposite process that takes place in nuclear fission (for fission, think Three Mile Island and Hiroshima). In fission the nucleus of an atom is split into pieces, with fusion we are joining atomic nuclei together. Both are accompanied by the release of energy (nuclear fusion is used in the hydrogen bomb).
Controlling and sustaining the reaction (thermonuclear ignition) to harness as a power source has been the challenge of nuclear fusion. Once ignition is achieved, the NIF will generate more energy that is required to maintain its operation. A lot more. The path to ignition experiments are scheduled to begin in 2010.
“When all 192 beams are operational in 2009, NIF will direct nearly two million joules of ultraviolet laser energy in billionth-of-a-second pulses to the target chamber center. When all that energy slams into millimeter-sized targets, it can generate unprecedented temperatures and pressures in the target materials – temperatures of more than 100 million degrees and pressures more than 100 billion times Earth’s atmosphere.” NIF: The ‘Crown Joule’ of Laser Science lasers.llnl.gov
The NIF’s three interconnected buildings take up three football fields and include; an optics assembly cleanroom, the laser power room, the target area, and diagnostics/control.
The machine is quite simply humanity at its finest. The precision required is astounding.
“[The] NIF’s pointing accuracy can be compared to standing on the pitcher’s mound at AT&T Park in San Francisco and throwing a strike at Dodger Stadium in Los Angeles, some 350 miles away. Because the precise alignment of NIF’s laser beams is extremely important for successful operation, the requirements for vibrational, thermal and seismic stability are unusually demanding. Critical beampath component enclosures (generally for mirrors and lenses), many weighing tens of tons, were located to a precision of 100 microns using a rigorous engineering process for design validation and as-installed verification.” NIF: The ‘Crown Joule’ of Laser Science lasers.llnl.gov
The process if fascinating. Starting with a small pulse of laser light, the NIF “conditions” the beam by passing it through an ingenious series of amplifiers. A tremendous amount of energy is fed into infused laser glass which excites the laser pulse as it passes through. To create an amplification loop, the NIF uses custom “large aperture optical switches” called PEPC’s that generate a plasma field to reflect the beam. Once amplified, the beam passes through special KDP crystal lenses before being focused on the target. Growing the KDP lenses at these sizes was invented especially for the NIF.
The project is not without its drama and skeptics. A French version is having major difficulties and early construction of the NIF was mismanaged. There is also no guarantee that the NIF will reach ignition. In fact, the NIF was almost canceled only to be saved when it was discovered that in the least, it can be used to test nuclear weapon technology.
“NIF is crucial to the NNSA (Nuclear) Stockpile Stewardship Program because it will be able to create the extreme conditions of temperature and pressure that exist on Earth only in exploding nuclear weapons and that are therefore relevant to understanding the operation of our modern nuclear weapons.” Plasma 2010 Committee, Plasma Science: Advancing Knowledge in the National Interest, National Research Council, 2007 nap.edu
Congratulations and good luck to the NIF team on a successful and sustained nuclear fusion reaction so we can put this whole nuclear weapon thing behind us.
Credit is given to Lawrence Livermore National Security, LLC, Lawrence Livermore National Laboratory, and the Department of Energy under whose auspices this work was performed.
Read more at:
The National Ignition Facility & Photon Science Website
The National Ignition Facility Comes to Life
World’s largest laser opens for business in California on Wired.com
