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The advancement by Lawrence Livermore National Laboratory researchers will be built on to further develop fusion energy research.
Category: nuclear energy – Page 45
Measurements of solar neutrinos proved that our star is powered by nuclear reactions and has brought to light many other details about the Sunâs inner workings. They also led to the discovery of neutrino oscillationsâa phenomenon that is difficult to reconcile with established theories. Current neutrino research mostly relies on neutrinos generated on Earth by reactors and accelerators. But some physicists argue that there is still a lot to be done with neutrinos generated in the Sun. A new generation of solar-neutrino experiments may help in solving outstanding questions about both neutrinos and solar physics, these scientists say.
The study of solar neutrinos began in the late 1960s. Using a detector filled with dry-cleaning fluid and placed in South Dakotaâs Homestake gold mine, physicist Raymond Davis and his colleagues observed the first neutrino signal from the Sun. They were surprised, however, to find that the number of neutrinos was one third of what models predictedâa mystery that led to a âneutrino gold rush,â with many new experiments staking claims to different energy and length scales related to the neutrino behavior. Eventually, physicists explained the missing neutrinos as resulting from oscillations between neutrino flavors (see Nobel Focus: Neutrino and X-ray Vision). These oscillations implied that neutrinos have mass, in tension with the standard model of particle physics.
The study of neutrino oscillations continues with efforts to pin down the neutrino masses and mixing parameters that determine the oscillating behavior. The main target, however, is no longer solar neutrinos. âThe majority of the community, by a large margin, is focused on accelerator neutrinos,â says Michael Smy from the University of California, Irvine. The reason for this shift, he says, is that an accelerator experiment can explore higher-energy neutrinos and control the source-detector distance over which oscillations may occur. Researchers can also switch the accelerator on and off, which helps remove certain backgrounds.
A study of neutrinos from the Sun has measured the signal from the so-called CNO cycle, offering a direct measure of the elemental abundances in the Sunâs core.
Solar neutrinos are copiously produced by hydrogen fusion reactions in the Sunâs core. Therefore, they are the direct evidence that the Sun is powered by nuclear reactions. Measurements of solar neutrinos have provided information about the temperature and density of the solar interior, but uncertainties remain about the chemical ingredients. Now the Borexino Collaboration reports a new measurement of the neutrino flux produced by the so-called CNO hydrogen burning cycle in the Sun [1]. This cycleâwhich requires the presence of carbon ©, nitrogen (N), and oxygen (O)âproduces neutrinos that carry enormous diagnostic power relating to the properties of the solar interior. By measuring these neutrinos, the collaboration provides a precious piece of information about the elemental makeup of the Sun, bringing us closer to resolving a controversy that has plagued solar physics for over 20 years [2].
Stars spend about 90% of their lifetimes fusing hydrogen into helium, producing two neutrinos in the process. The pp chainâor protonâproton chainâand CNO cycle are the two fundamental modes by which stellar fusion occurs. Whether a star is dominated by the pp chain or the CNO cycle depends on its core temperature, which is primarily determined by the mass of the star. In the Sun and similar low-mass stars, the pp chain generates almost all the nuclear energy; the CNO cycle is the main power source for more massive stars. The pp chain is a series of nuclear reactions that require no additional nuclei besides hydrogen as fuel. By contrast, the CNO cycle relies on the presence of C, N, and O nuclei as catalysts in the production of helium (Fig. 1). In the Sun, this catalytic process introduces a linear dependence between the amount of C, N, and O and the flux of CNO neutrinos. Thus, CNO neutrinos are a powerful tool for probing the chemical composition in the Sunâs core.
For the first time in history, US scientists at the National Ignition Facility at the Lawrence Livermore National Laboratory in California successfully produced a nuclear fusion reaction resulting in a net energy gain. Science educator Bill Nye explains why this is such a big breakthrough. #CNN #News
The Halo Drive
Posted in cosmology, media & arts, nuclear energy, physics, space travel
How could we one day travel between the stars with real physics? Perhaps the greatest challenge to interstellar flight is energetics â it takes vast amounts of energy to accelerate even small ships to 20% the speed of light. But what if we could steal that energy from where? Perhaps even a black hole. Enter the âhalo driveâ, a video by Prof David Kipping based on his new peer-reviewed research paper on the subject.
This video is based on research conducted at the Cool Worlds Lab at Columbia University, New York. You can now support our research program directly here: https://www.coolworldslab.com/support.
Further reading and resources:
âș Kipping, David (2018), âThe Halo Drive: Fuel Free Relativistic Propulsion of Large Mases via Recycled Boomerang Photonsâ, JBIS, 71458: https://arxiv.org/abs/1903.03423
âș Dyson, Freeman (1963), âGravitational Machinesâ, in A.G.W. Cameron, ed., Interstellar Communication, New York Benjamin Press: https://www.ifa.hawaii.edu/~barnes/ast242_s14/Dyson_Machines.pdf.
âș Breakthrough Starshot homepage: https://breakthroughinitiatives.org/initiative/3
âș Our Cool Worlds video giving some background on Breakthrough Starshot: https://youtu.be/Ksb6Vh0BT_E
âș Our Cool Worlds video on relativistic moving mirrors: https://youtu.be/msK9d9k6K0E
âș Our Cool Worlds video on mirror distortion effects: https://youtu.be/1iNA-GTocI0
âș Columbia University Department of Astronomy: http://www.astro.columbia.edu.
âș Cool Worlds Lab website: http://coolworlds.astro.columbia.edu.
Thereâs an error in the video at around 8:30, 2 trillion joules is the cumulative energy output of a typical nuclear power station after 2000 seconds, not 20 days.
The U.S. Department of Energy (DOE) has today confirmed the achievement of âfusion ignitionâ at Lawrence Livermore National Laboratory (LLNL) â a major scientific breakthrough, many decades in the making, which could pave the way to near-limitless clean power.
On 5th December, a team at LLNLâs National Ignition Facility (NIF) conducted the first controlled experiment in history to reach this milestone, also known as scientific energy breakeven, meaning it produced more energy from fusion than the laser energy used to drive it. This first-of-its-kind feat will provide invaluable insights into the fusion energy process, which scientists have been attempting to develop for nearly a century.
Inside the target chamber of LLNLâs National Ignition Facility, 192 laser beams delivered more than 2 million joules of ultraviolet energy to a tiny fuel pellet to create the fusion ignition. These lasers heated the capsule to 100,000,000°C â more than six times hotter than the Sunâs core, and compressed it to more than 100 billion times the pressure of Earthâs atmosphere. Under these unimaginable forces, the capsule would have imploded on itself, forcing its hydrogen atoms to fuse and release energy.
Researchers at the Lawrence Livermore National Laboratory claim to have achieved the seemingly impossible: generate more energy with a fusion reaction than they put into it, potentially paving the way for a truly environmentally friendly and safe source of power.
Their experiment, which involved using the âworldâs largest and highest energy laser systemâ at Livermoreâs National Ignition Facility to blast light at small capsules of deuterium-tritium fuel, generated 20 percent more energy than the amount required to power the system.
Despite the modest energy output â the system generated enough power to boil around two to three kettles â the researchers are boldly predicting that it could represent a major turning point in the quest to turn fusion energy into a reality.
This new breakthrough opens the door to limitless clean energy.
The time has finally come. Scientists at the Lawrence Livermore National Laboratory (LLNL) are the first in the world to demonstrate net energy production from nuclear fusion.
In other words, theirs was the first ever nuclear fusion experiment to produce more energy than was required to run the experiment in the first place.
Researchers achieved the milestone, also known as fusion ignition, at LLNLâs National Ignition Facility (NIF) during a controlled fusion experiment last Monday, Dec. 5, according to a statement from the US Department of Energy (DOE). They waited for peer-review results before revealing the results to the world.
US officials announced Tuesday that researchers have produced a nuclear fusion reaction resulting in a net energy gain. Follow here for live news updates.
WASHINGTON, Dec 12 (Reuters) â The U.S. Department of Energy on Tuesday will announce that scientists at a national lab have made a breakthrough on fusion, the process that powers the sun and stars that one day could provide a cheap source of electricity, three sources with knowledge of the matter said.
The scientists at Lawrence Livermore National Laboratory in California have achieved a net energy gain for the first time, in a fusion experiment using lasers, one of the people said.
While the results are a milestone in a scientific quest that has been developing since at least the 1930s, the ratio of energy going into the reaction at Livermore to getting energy out of it needs to be about 100 times bigger to create a process producing commercial amounts of electricity, one of the sources said.