Inland Valley Daily Bulletin

Fusion research breakthrou­gh reported

Advance may lead to new energy source, assist in maintenanc­e of nuclear weapons without testing

- By Kenneth Chang

Scientists at a federal nuclear weapons facility in Livermore have made a potentiall­y significan­t advance in fusion research that could lead to a source of bountiful energy in the future, according to a government official.

The advance is expected to be announced today by the Department of Energy, which said a “major scientific breakthrou­gh” was made at Lawrence Livermore National Laboratory in the Bay Area.

Jennifer Granholm, the energy secretary, and White House and other Energy Department officials are expected to be in attendance. The Financial Times reported Sunday that the scientific advance involves the National Ignition Facility, which uses giant lasers to create conditions that briefly mimic the explosions of nuclear weapons.

The government official, who spoke anonymousl­y to discuss results that are not yet public, said that the fusion experiment at the National Ignition Facility achieved what is known as ignition, where the fusion energy generated equals the laser energy that started the reaction. Ignition is also called energy gain of one.

The breakthrou­gh “could be a game changer for the world,” said Rep. Ted Lieu, a California Democrat.

Such a developmen­t would improve the ability of the U.S. to maintain its nuclear weapons without nuclear testing and could set the stage for future progress that could one day lead to the use of laser fusion as an energy source.

Although not yet publicly announced, the news has quickly bounced among physicists and other scientists who study fusion.

“Yesterday a scientist friend sent me a note stating that Livermore

had exceeded energy gain of one just last week and would be announcing the result on Tuesday,” Stephen Bodner, a retired plasma physicist who has long been a critic of the National Ignition Facility, said in an email Monday morning. “They deserve commendati­ons for reaching their goal.”

WHAT IS FUSION?

Fusion is the thermonucl­ear reaction that powers the sun and other stars — the fusing of hydrogen atoms into helium. The mass of helium is slightly less than the original hydrogen atoms. Thus, by Einstein’s E=mc2 equation, that difference in mass is converted into a burst of energy.

Fusion that could be produced in a controlled fashion on Earth could mean an energy source that does not produce greenhouse gases like coal and oil, or dangerous, long-lived radioactiv­e waste, as current nuclear power plants do.

HOW DO YOU PRODUCE FUSION WITHOUT A STAR?

Most fusion efforts to date have employed doughnut-shaped reactors known as tokamaks. Within the reactors, hydrogen gas is heated to temperatur­es hot enough that the electrons are stripped away from the hydrogen nuclei, creating what is known as a plasma

— clouds of positively charged nuclei and negatively charged electrons. Magnetic fields trap the plasma within the doughnut shape, and the nuclei fuse together, releasing energy in the form of neutrons flying outward.

Tuesday’s announceme­nt, however, involves a different approach. The National Ignition Facility consists of 192 gigantic lasers, which fire simultaneo­usly at a metal cylinder about the size of a pencil eraser. The cylinder, heated to some 5.4 million degrees Fahrenheit, vaporizes, generating an implosion of X-rays, which in turn heats and compresses a BB-size pellet of frozen deuterium and tritium, two heavier forms of hydrogen. The implosion fuses the hydrogen into helium, creating fusion.

WHAT LASER FUSION ADVANCES HAVE BEEN

MADE SO FAR?

The main purpose of the National Ignition Facility, built at a cost of $3.5billion, is to conduct experiment­s that help the United States maintain its nuclear weapons without nuclear test explosions. Proponents also said it could advance fusion research that could lead to viable commercial power plants.

However, the facility initially generated hardly any fusion at all. In 2014, Livermore scientists finally reported success, but the energy produced then was minuscule, the equivalent of what a 60-watt light bulb consumes in five minutes.

Last year, Livermore scientists reported a major leap, a burst of energy — 10 quadrillio­n watts of power

— that was 70% as much as the energy of laser light hitting the hydrogen target.

But the burst — essentiall­y a miniature hydrogen bomb — lasted only 100 trillionth­s of a second.

The report by the Financial Times on Sunday suggests Livermore will announce that in the latest experiment the fusion energy produced exceeded the amount of laser energy hitting the hydrogen target.

For that to occur, the fusion reaction had to be selfsustai­ning, meaning the torrent of particles flowing outward from the hot spot at the center of the pellet heated surroundin­g hydrogen atoms and caused them to fuse as well.

WHAT ARE THE OBSTACLES TO FUSION POWER?

An important caveat is that the claim focuses on the laser energy hitting the hydrogen target. The National Ignition Facility’s lasers are extremely inefficien­t, meaning only a small fraction of the energy used to power the lasers actually makes it into the beams themselves.

More modern technology such as solid-state lasers would be more efficient but still far from 100% fusion; for this to be practical, the fusion energy output must be at least several times greater than that of the incoming lasers.

DOES TUESDAY’S ANNOUNCEME­NT MEAN WE’LL HAVE CHEAP FUSION ENERGY SOON?

No. Even if scientists figure out how to generate bigger bursts of fusion, immense engineerin­g hurdles would remain.

The National Ignition Facility’s experiment­s have studied one burst at a time.

A practical fusion power plant using this concept would require a machine-gun pace of laser bursts with new hydrogen targets sliding into place for each burst. Then the torrents of neutrons flying outward from the fusion reactions would have to be converted into electricit­y.

The laser complex fills a building with a footprint equal to three football fields — too big, too expensive, too inefficien­t for a commercial power plant.

A manufactur­ing process to mass-produce the precise hydrogen targets would have to be developed.

 ?? LAWRENCE LIVERMORE NATIONAL LABORATORY VIA THE NEW YORK TIMES ?? A technician works at the National Ignition Facility of the Lawrence Livermore National Laboratory in Livermore, which the Department of Energy says has made a “major scientific breakthrou­gh.”
LAWRENCE LIVERMORE NATIONAL LABORATORY VIA THE NEW YORK TIMES A technician works at the National Ignition Facility of the Lawrence Livermore National Laboratory in Livermore, which the Department of Energy says has made a “major scientific breakthrou­gh.”
 ?? JASON LAUREA — LAWRENCE LIVERMORE NATIONAL LABORATORY VIA THE NEW YORK TIMES ?? A BB-sized cryogenic target is used to reach the burning plasma state in an experiment in November 2020and February 2021at the National Ignition Facility of the Lawrence Livermore National Laboratory in Livermore. Scientists at the federal nuclear weapons facility have made a potentiall­y significan­t advance in fusion research that could lead to a source of bountiful energy in the future, according to a government official.
JASON LAUREA — LAWRENCE LIVERMORE NATIONAL LABORATORY VIA THE NEW YORK TIMES A BB-sized cryogenic target is used to reach the burning plasma state in an experiment in November 2020and February 2021at the National Ignition Facility of the Lawrence Livermore National Laboratory in Livermore. Scientists at the federal nuclear weapons facility have made a potentiall­y significan­t advance in fusion research that could lead to a source of bountiful energy in the future, according to a government official.

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