The Argon Fluoride (ArF) Laser: Harnessing the Incredible Power of the Sun

Nuclear fusion has taken another important step forward in our advance toward a clean, renewable energy source. According to the publication New Atlas, “The US Naval Research Laboratory (NFL) is developing an Argon Fluoride (ArF) laser that may one day make fusion power a practical commercial technology.” 

An argon laser is a device that uses argon gas and produces a very intense short-wavelength laser that can credibly scale to the energy and power required for high gain inertial fusion, sometimes called ignition.   As reported in Newsweed, inertial fusion is the energy needed to both start and sustain a series of ongoing nuclear fusion reactions, which is the precursor to providing an inexpensive, safe form of electrical energy. 

Lasers thus far have been limited in the robustness of creating this rection, but an ArF could be a game-changer.  Steve Obenschain, Ph.D., a research physicist at NRL, states, “The NIF result is impressive and highlights the need to look ahead to what laser technologies will accelerate future progress. The NRL ArF laser technology provides a path to much higher fusion gain and yields,” thus overcoming inertial fusion issues that have plagued the advancement of nuclear fusion research. 

The ArF would meet two simultaneous requirements for manifesting fusion power. First, it would need to generate the required heat and pressure necessary to kick start the fusion process. Secondly, the process has to be sustainable, or reproducible so that it continually generates much more energy than it takes to be initially generated.

The ArF takes care of both of those requirements. As New Atlas explains,  “The goal for the past 75 years has been to produce temperatures in excess of 100 million degrees C (180 million degrees F) and the pressure needed to ignite the fusion reaction and generate enough surplus energy to sustain it. That in itself would be a major achievement, but the technology also has to be able to sustain the reaction indefinitely, while also being cheap enough and the reactor small enough for it to be practical.”

Moreover, at this juncture, the new advance will propel previous advancements, making the reality of viable nuclear fusion that is simultaneously affordable.

As Obenschain puts it, “Our work so far indicates there is no fundamental obstacle preventing an ArF direct-drive inertial fusion energy system from meeting these requirements,” adding “The advantages could facilitate the development of modest size, less expensive fusion power plant modules operating at laser energies less than 1 mega joule,” which  “would drastically change the existing view on laser fusion energy being too expensive and power plants being too large.”

The ArF is a major improvement from its predecessor, the krypton fluoride (KrF) laser. Oddly, the word “major” means just a few percentage points of improvement in terms of efficiency when it comes to nuclear fusion.

The Royal Society reports that “The greater than 16% intrinsic efficiency with an ArF driver would enable substantially higher electrical efficiency for delivering laser light to target than a KrF system,” translating into a “gain estimate” of  75%, an incredible jump in efficiency. As Obenschain points out, this would be “enough fuel feedstock readily available to last thousands of years.”

The ArF works by focusing its powerful lasers on beads of deuterium or tritium, which are heavy isotopes of hydrogen, which cause them to heat and compress in a matter of seconds, thereby causing hydrogen atoms to fuse. This fusion process then releases vast amounts of energy that would be used to heat water that then producers the steam to power turbines, thus generating incredible amounts of electricity. In essence, man-made nuclear fusion is tantamount to creating a small contained, controllable sun, right here on earth.  

The use of nuclear fusion differs greatly from nuclear fission, which is the splitting of atoms. Unlike the fission process, however nuclear fusion not only creates much more energy, making it markedly more efficient, it also produces fewer nuclear waste products.

The International Atomic Energy Association (IAEA) explains, “A fusion reactor produces helium, which is an inert gas. It also produces and consumes tritium within the plant in a closed circuit. Tritium is radioactive (a beta emitter) but its half-life is short. It is only used in low amounts so, unlike long-lived radioactive nuclei, it cannot produce any serious danger.” 

Not everyone is on board with the promise of nuclear fusion, especially with regard to nuclear byproducts. The Bulletin of the Atomic Scientists writes, “In fact, these neutron streams lead directly to four regrettable problems with nuclear energy: radiation damage to structures; radioactive waste; the need for biological shielding; and the potential for the production of weapons-grade plutonium 239—thus adding to the threat of nuclear weapons proliferation, not lessening it, as fusion proponents would have it.”

Still, the ArF has the considerable financial backing of the BETHE program, which is dedicated to enhancing “performance levels and the number of lower-cost fusion approaches that might eventually lead to commercial fusion energy with competitive capital cost and levelized cost of energy.” And because of the growing push to reduce carbon emissions in the light of climate change, it is likely that scientists will continue to refine technologies to harvest the power of the sun.