Billions of anti-matter particles

Very interesting research.

The release:

Billions of particles of anti-matter
created in laboratory

LIVERMORE, Calif. – Take a gold sample the size of the head of a push pin, shoot a laser through it, and suddenly more than 100 billion particles of anti-matter appear.

The anti-matter, also known as positrons, shoots out of the target in a cone-shaped plasma “jet.”

This new ability to create a large number of positrons in a small laboratory opens the door to several fresh avenues of anti-matter research, including an understanding of the physics underlying various astrophysical phenomena such as black holes and gamma ray bursts.

Anti-matter research also could reveal why more matter than anti-matter survived the Big Bang at the start of the universe.

“We’ve detected far more anti-matter than anyone else has ever measured in a laser experiment,” said Hui Chen, a Livermore researcher who led the experiment. “We’ve demonstrated the creation of a significant number of positrons using a short-pulse laser.”

Chen and her colleagues used a short, ultra-intense laser to irradiate a millimeter-thick gold target. “Previously, we concentrated on making positrons using paper-thin targets,” said Scott Wilks, who designed and modeled the experiment using computer codes. “But recent simulations showed that millimeter-thick gold would produce far more positrons. We were very excited to see so many of them.”

In the experiment, the laser ionizes and accelerates electrons, which are driven right through the gold target. On their way, the electrons interact with the gold nuclei, which serve as a catalyst to create positrons. The electrons give off packets of pure energy, which decays into matter and anti-matter, following the predictions by Einstein’s famous equation that relates matter and energy. By concentrating the energy in space and time, the laser produces positrons more rapidly and in greater density than ever before in the laboratory.

“By creating this much anti-matter, we can study in more detail whether anti-matter really is just like matter, and perhaps gain more clues as to why the universe we see has more matter than anti-matter,” said Peter Beiersdorfer, a lead Livermore physicist working with Chen.

Particles of anti-matter are almost immediately annihilated by contact with normal matter, and converted to pure energy (gamma rays). There is considerable speculation as to why the observable universe is apparently almost entirely matter, whether other places are almost entirely anti-matter, and what might be possible if anti-matter could be harnessed. Normal matter and anti-matter are thought to have been in balance in the very early universe, but due to an “asymmetry” the anti-matter decayed or was annihilated, and today very little anti-matter is seen.

Over the years, physicists have theorized about anti-matter, but it wasn’t confirmed to exist experimentally until 1932. High-energy cosmic rays impacting Earth’s atmosphere produce minute quantities of anti-matter in the resulting jets, and physicists have learned to produce modest amounts of anti-matter using traditional particle accelerators. Anti-matter similarly may be produced in regions like the center of the Milky Way and other galaxies, where very energetic celestial events occur. The presence of the resulting anti-matter is detectable by the gamma rays produced when positrons are destroyed when they come into contact with nearby matter.

Laser production of anti-matter isn’t entirely new either. Livermore researchers detected anti-matter about 10 years ago in experiments on the since-decommissioned Nova “petawatt” laser – about 100 particles. But with a better target and a more sensitive detector, this year’s experiments directly detected more than 1 million particles. From that sample, the scientists infer that around 100 billion positron particles were produced in total.

Until they annihilate, positrons (anti-electrons) behave much like electrons (just with an opposite charge), and that’s how Chen and her colleagues detected them. They took a normal electron detector (a spectrometer) and equipped it to detect particles with opposite polarity as well.

“We’ve entered a new era,” Beiersdorfer said. “Now, that we’ve looked for it, it’s almost like it hit us right on the head. We envision a center for antimatter research, using lasers as cheaper anti-matter factories.”

Chen will present her work at the American Physical Society’s Division of Plasma Physics meeting Nov. 17-21 at the Hyatt Regency Reunion in Dallas. S.C. Wilks, E. Liang, J. Myatt, K. Cone ,L. Elberson, D.D. Meyerhofer, M. Schneider, R. Shepherd, D. Stafford, R. Tommasini, P. Beiersdorfer are the collaborators on this project.

Founded in 1952, Lawrence Livermore National Laboratory is a national security laboratory, with a mission to ensure national security and apply science and technology to the important issues of our time. Lawrence Livermore National Laboratory is managed by Lawrence Livermore National Security, LLC for the U.S. Department of Energy’s National Nuclear Security Administration.

Breaking down the Large Hadron Collider mission profile and factfile

I’ve blogged quite a  bit about the Large Hadron Collider, most of it centered on covering the facts — not the fear — of what’s going to happen once the first proton hits the accelerator. And speaking of hitting, you can hit this link for all my LHC blogging.

This link covers the more exciting aspects of the LHC. Namely the mission profile for the collider and some general facts about this awesome piece of machinery.

From the link:

World’s biggest atom-smasher: Mission profile

Following is a mission profile of the Large Hadron Collider (LHC), the world’s biggest atom-smasher, which is due to start operations on Wednesday:

– Hunt for the HIGGS BOSON, a theorised particle that would explain why other particles have mass. Confirming the Higgs would fill a huge gap in the so-called Standard Model, the theory that summarises our present knowledge of particles. Over the years, scientists have whittled down the ranges of mass that the Higgs is likely to have. But they have lacked a machine capable of generating collisions powerful enough to to confirm whether this so-called God particle really does exist.

– Explore SUPERSYMMETRY, the notion that a whole bestiary of related but more massive particles exists beyond those in the Standard Model. Supersymmetry could explain one of the weirdest discoveries of recent years — that visible matter only accounts for some four percent of the cosmos. Dark matter (23 percent) and dark energy (73 percent) account for the rest. A popular theory is that dark matter comprises supersymmetric particles called neutralinos.

– Investigate the mystery of MATTER AND ANTI-MATTER. When energy transforms into matter, it produces a particle and its mirror image — called an anti-particle — which holds the opposite electrical charge. When particles and anti-particles collide, they annihilate each other in a small flash of energy. According to conventional theories of the cosmos, matter and anti-matter should exist in equal amounts, but the puzzle is that anti-matter is rare.

– Replicate the earliest moments after the BIG BANG that created the Universe. At its primal stage, matter existed as a sort of hot, dense soup called quark-gluon plasma. As it cooled, sub-atomic particles called quarks clumped together to form protons and neutrons and other composite particles. The LHC will smash heavy ions together, briefly generating temperatures 100,000 times hotter than the centre of the Sun and freeing quarks from their confinent. The researchers can then see how the liberated quarks aggregate to form ordinary matter.