Nature: The National Ignition Facility (NIF) is a fusion research project based at Lawrence Livermore National Laboratory in California. After the failure of a six-year drive to use lasers to implode matter and ignite fusion, the plans for the facility have shifted. However, the investigation into what went wrong is still ongoing. An independent report initiated by the Department of Energy has been released by the National Nuclear Security Administration, which oversees the operation of NIF. The panel’s findings agree with previous project reviews. The independent scientists highlighted problems in controlling the symmetry of the implosion, which is necessary to maintain stable fusion, and in controlling the mixing of hot and cold fuels. They also noted that because of the complexity, current computers and software simply may not be capable enough. The panel was split, however, as to whether NIF could ever achieve successful ignition.
Ars Technica: Neutral particles are much harder to accelerate than charged particles for the very reason that researchers want to accelerate them—they don’t respond to electric and magnetic fields. A team of researchers led by R. Rajeev of the Tata Institute of Fundamental Research in Mumbai, India, has adapted laser plasma acceleration for use with neutral particles. Rajeev’s team began by using high-energy laser pulses to accelerate atoms and strip off their electrons, which left behind a plasma of positively charged ions moving in coherent waves. The researchers then created a slow-moving beam of so-called Rydberg atoms, whose outer electrons are loosely bound to their nuclei. Next, the team introduced the Rydberg atoms into the already-accelerated beam of fast-moving ions. When the two types of particles collided, the Rydberg atoms transferred their electrons to the ions. Separating out any residual ions left the researchers with a beam of neutral atoms with MeV energies, a billion times greater than had been achieved by previous neutral-particle accelerators. The atom accelerator is much less powerful than ion accelerators, but being only desktop-sized, it has a wider range of potential applications such as in nanolithography and further studies of plasma behaviors.
MIT News: Collisions between protons and lead ions at CERN’s Large Hadron Collider may have produced a form of matter called a color-glass condensate, which is a liquid-like wave of gluon plasma. In 2 million collisions seen by the LHC’s Compact Muon Solenoid (CMS), some of the resulting particles exhibited behavior that suggested they were entangled. A normal particle collision results in an explosion of particles. But in the lead–proton collisions, some pairs of exploded particles followed matching paths, meaning each particle communicated its direction to the other via entanglement. Gunther Roland of MIT, who led the group analyzing the CMS data, had seen similar shared-path behavior in proton–proton collisions and the collisions of nuclei of heavy elements such as lead and gold. Heavy nuclei collisions produce a quark–gluon plasma, and proton–proton collisions are believed to create a color-glass condensate. Both plasmas sweep up the entangled particles and push them down identical paths. Roland said that the color-glass condensate had not been expected in the lead–proton collisions, which were being done to establish a point of reference for lead–lead collisions. Roland’s group plans additional collisions to try to determine if the color-glass condensate is the cause of the entangled behavior.
New York Times: Following news about “mounting concerns that the technical challenges” at Lawrence Livermore National Laboratory’s National Ignition Facility (NIF) may be “too great to be mastered on a tight time schedule,” a Times editorial proposes a hard congressional look “at whether the project should be continued, or scrapped or slowed.” The editors observe that technical reviews “have made it clear” that scientists “do not fully understand how the process is working and may not be able to achieve ignition quickly.” Given the $5 billion facility’s $290 million annual operating budget, the editors report a “sharp split among experts” on whether NIF is “worth the money.” Alluding to NIF’s twin missions of nuclear weapon stockpile stewardship and fusion power demonstration, they suggest that if “the main goal is to achieve a power source that could replace fossil fuels,” they “suspect the money would be better spent on renewable sources of energy that are likely to be cheaper and quicker to put into wide use.”
New York Times: Science writer William Broad calls Lawrence Livermore National Laboratory’s National Ignition Facility (NIF) “one of the most expensive federally financed science projects ever.” He reports that “it has not worked,” predicts that Congress “is going to want some explanations,” and adds that the “failure could have broad repercussions” for federal science initiatives generally. Such initiatives, he writes, “seldom disappoint on such a gargantuan scale, and the setback comes in an era of tough fiscal choices and skepticism about science among some lawmakers.” Broad reports varied opinions, including a call for reduced funding, emphasis on NIF’s usefulness in nuclear-weapon stockpile stewardship, ridicule of the project as “the National Almost Ignition Facility, or NAIF,” and assertions that “challenge of planned breakthroughs” is unrealistic. He quotes Penrose Albright, the laboratory director: “Everybody believes we can get there. But we’re exploring parts of physical space that no one has ever done before, and that’s a hard problem.”
Science: The new tungsten and beryllium lining installed last year at the Joint European Torus (JET) fusion reactor in Culham, England, has experienced significantly less erosion and fuel absorption than the lining used on earlier reactors. That is promising news for ITER, the international prototype fusion energy reactor under construction in Cadarache, France, which will have a similar lining. Both JET and ITER are designed to use electromagnetic fields to contain a plasma of deuterium and tritium. However, because the plasma is unstable, it sometimes makes contact with the walls of the reactor. When that happens, the plasma can cool and erode the lining material. JET’s previous, carbon-lined wall absorbed significant amounts of tritium, which could destabilize the plasma when it later escaped from the carbon. By minimizing the amount of fuel absorption, the researchers believe it will be easier to maintain a stable plasma.
New Scientist: The Large Hadron Collider (LHC) at CERN created a quark–gluon plasma whose temperature exceeded 5 gigakelvin (5 trillion °C). The LHC is primarily known for its proton collisions, which revealed the existence of a particle very like the Higgs boson. However, researchers there also use the LHC to collide lead ions. The resulting plasma, made of extremely high energy quarks and gluons, was 40% hotter than the previous record temperature, established by the Relativistic Heavy Ion Collider (RHIC) at Brookhaven National Laboratory in New York. Both the LHC and RHIC are re-creating conditions that occurred just microseconds after the Big Bang. One of the goals of the research is to determine at what energy the quark–gluon plasma settles into normal matter.
Science Daily: Researchers at the US Department of Energy’s SLAC accelerator laboratory used rapid-fire laser pulses to flash-heat a tiny piece of aluminum foil to about 2 million °C. The experiments used SLAC’s Linac Coherent Light Source, which is a billion times brighter than any other x-ray source, to both create and probe the sample. “Making extremely hot, dense matter is important scientifically if we are ultimately to understand the conditions that exist inside stars and at the center of giant planets within our own solar system and beyond, ” said Sam Vinko, a postdoctoral researcher at Oxford University and lead author of the group’s paper published in Nature.
BBC: The UK’s Atomic Weapons Establishment and its Rutherford Appleton Laboratory have formed a partnership with the US Department of Energy’s National Ignition Facility (NIF). The three labs will work together to develop a means for generating electricity from laser-powered fusion. The UK leads High-Power Laser Energy Research (HiPER), a European project aimed at moving laser fusion technology toward a commercial plant. Begun in 2005, HiPER is now in the midst of a detailed design phase. The primary goals of NIF, which has been in operation since 2009, are to achieve fusion with high energy gain and to study the conditions that prevail in hydrogen bombs. Speaking about the new partnership, David Willetts, the UK’s science minister, said, “This is an absolutely classic example of the connections between really high-grade theoretical scientific research, business, and commercial opportunities, and of course a fundamental human need: tackling pressures that we’re all familiar with on our energy supply.”
Nature News: The world’s largest fusion experiment is finally beginning to take shape. Workers at a vast site in southern France have dug the 17-meter-deep pit that will house the ITER reactor, and will soon install 500 pillars of steel-reinforced concrete that should protect the machine during an earthquake. But even as they toil, a quake halfway around the world has struck a blow to the project.
The 11 March earthquake and tsunami that hit Japan, one of seven partners in ITER, severely damaged key facilities for testing the reactor’s components. Unless repairs can be made or work reassigned quickly, the damage could cause a delay of “perhaps several years,” according to Osamu Motojima, ITER’s director. Motojima says that he and his team are looking at ways to reduce the impact. “At present my target is less than one year’s delay,” he says.