Recently, the United States National Ignition Facility (NIF), known as the “artificial sun,” completed its first comprehensive ignition experiment—the energy emitted by 192 laser systems created a high temperature of 6 million degrees Fahrenheit, which is equivalent to the core of stars or giant planets. temperature. As the world's largest laser fusion device, NIF has spent 3.55 billion U.S. dollars (about 23.5 billion U.S. dollars) from taxpayers since it was built in 1997. Researchers at no cost to study not only how to "control the energy of the sun" but also carry the dream of human clean energy.


The target chamber is made of aluminum plate up to 10 cm thick.

At the Livermore National Laboratory in California, a mysterious building is still under construction. Over the past decade or so, this huge building has always been the focus of environmentalists. However, on November 2, an ignition experiment conducted here shook the scientific community. Because as the world’s first reactor capable of producing continuous nuclear fusion, the “artificial sun” will rewrite human history once it succeeds.

Create "Little Sun" on Earth

The largest and most commercially valuable energy available to humanity today is undoubtedly nuclear energy. The principle of using nuclear energy in nuclear power plants is nuclear fission, that is, in the state of high temperature and high pressure, the heavy atoms such as uranium or plutonium are split into light atoms, resulting in a nuclear reaction mode that releases a large amount of energy. However, the use of nuclear energy by the National Ignition System is in the opposite direction. It is not nuclear fission but nuclear fusion. Nuclear fusion refers to the form of a nuclear reaction in which atoms of light masses, mainly cesium or ytterbium, occur at high temperatures and pressures, where nuclei interact with one another to generate new, heavier nuclei, which are accompanied by tremendous energy release. Solar glow is the use of nuclear fusion energy.

Compared with nuclear fission, nuclear fusion is not only safe, but also relatively environmentally friendly. The Livermore National Ignition Device once said to the media: “The sun’s light and heat reach the earth, will not produce any radioactive by-products, and will be able to produce efficiently for a long period of time. If we replace the sun with the nuclear fusion reactor we are studying, It is equivalent to building a small sun that provides clean energy on Earth."

Release 1.3 megajoules of energy

At present, this "Little Sun" has already begun to take shape, and encouraging experiments have been conducted and valuable experimental data have been obtained. A team of Livermore National Ignition Devices said that on November 2th they fired 192 laser beams at the fusion reactor center and used them to target a small sphere that was only the size of a peanut but contained both helium and neon gas. This small sphere releases up to 1.3 megajoules of energy, and its core maximum temperature is about 6 million degrees Fahrenheit.

National Ignition Director Edward Moses said that although the test failed to reach the center temperature of 27 million degrees Fahrenheit and did not trigger the expected sustained nuclear fusion reaction, the results of these tests are still very encouraging. "The experiment has convinced us that we will be able to achieve the ignition conditions in the nuclear and nuclear fusion targets." Moses also said that American scientists are determined to achieve this goal in 2012.

In order to achieve nuclear fusion combustion, it is necessary first to ignite special fuels consisting of the isotopes of hydrogen, helium and neon.


Workers fill the target target room with "artificial sun" core devices.

In the 1970s, scientists began experimenting with powerful laser beams, compressing and heating isotopes of hydrogen to bring them to melting points, a technique known as inertia-constrained nuclear fusion. The role of the laser emitter is to promote the rapid and continuous generation of this nuclear fusion. Targets containing helium and neon gas are stimulated by the outside and they will explode to form a shock wave, further accelerating the burning of the target's core, and the continuation of this combustion. Also longer.

Once this nuclear fusion becomes a reality, the temperature of the target chamber in the national ignition device will exceed 100 million degrees Fahrenheit, and the internal pressure will exceed 100 billion times the earth's atmospheric pressure. National Ignition Director Edward Moses said: “We have conducted a decade of research to produce nuclear fusion combustion in the laboratory. At present, nuclear power plants that use nuclear fusion or nuclear fission to generate energy have generated a substantial amount of power in the past 50 years. Increasing, but so far it has not been demonstrated that the method of continuous combustion and energy generation after the fusion of helium and neon gas can be put into use.” So Moses said that the significance of the “artificial sun” experiment is self-evident, “Once we have mastered the realization of the internal solar nucleus With fusion technology, our children and grandchildren will enjoy the leap of science and technology, and the era of energy shortage will never return."

"Artificial Sun" is highly technical and has broad application prospects

In fact, apart from the "artificial sun" plan of the United States, China, Russia and other world powers are currently studying nuclear fusion technology similar to "artificial sun."

The target of nuclear reactors in the National Ignition Plant “Artificial Sun” is helium and thorium. The thorium can be extracted from seawater using uncomplicated technology; helium is present in metallic lithium, and lithium is a common element in soil. Therefore, the exploitation and utilization of earthworms and earthworms in reality is easier and simpler than the use of uranium or plutonium for nuclear fission.

The National Ignition Device has made a visual comparison of the prospects for the use of cesium and lanthanum on its website. They cited as an example that due to the presence of helium in sea water, after a certain conversion, 1 gallon of seawater can provide the equivalent of 300 gallons of gasoline, and 50 gallons of seawater can produce energy equivalent to 2 tons of coal. “They are environmentally friendly. After large-scale application, they can reduce the use of fossil fuels and greatly reduce carbon emissions.”

More importantly, thorium and thorium are not as intense as uranium or plutonium. The future uses of them as radioactive byproducts produced by reactors are also less than current nuclear fission nuclear power plants.

National Ignition Officer officials estimate that the power station that uses nuclear fusion reactors will begin operations in 2020 and that by 2050, 25% of U.S. civilian energy will be supplied by nuclear fusion.

130 tons target target chamber is the core

Since the late 1990s, Livermore National Laboratories has started to build "artificial sun" and so far the entire plan has invested about 3.55 billion U.S. dollars. The comprehensive ignition test conducted on November 2 is the most successful test to date. In the future, there are more complex and more challenging tests performed in the national ignition device.

The National Ignition Facility is a 10-story building with an area equivalent to three football fields. The media claimed that this ignition device is the world's largest laser science construction project, and thus became the center of the global "artificial sun" experiment, carrying the dream of human use of new energy. The National Ignition Device Control Room has a very advanced computerized automatic control and integration system. It mimics the mission control center of NASA in Houston and is known as one of the most complex automatic control systems for scientific instrument design in history.

The National Ignition Unit is equipped with a target target room of 130 tons, which is the core part of the "Artificial Sun" program. The center hole in the target chamber has a diameter of 10 meters and is buried with 30 cm of concrete. There are 192 lasers next to it to emit neutrons to ignite the reactor and cause the glass objects containing helium and neon gas to generate extremely high temperatures. And high pressure.

The conditions of this target chamber will be close to or reach the conditions of the internal nuclear fusion reaction of the sun. The computer automation integrated system ensures the stability of the test, because the 850 computers make the laser emit laser light not more than 50 microseconds apart. (Text/Global Network, via Tencent Technology)

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