NASA AMS-2 Particle Detector on ISS Finds Dark matter in Cosmic Rays - Update

The Alpha Magnetic Spectrometer attached to the International Space Station.

Credit: NASA

New research published Thursday in the journal Physical Review Letters shows researchers are making important progress in the hunt for dark matter, using the Alpha Magnetic Spectrometer (AMS), a state-of-the-art cosmic ray particle physics detector located on the exterior of the International Space Station.

The results include new detections of anti-matter particles that could provide new clues in the search for dark matter, invisible matter that can't be directly detected but can be inferred. An overview of the latest findings can be found here.

Computer-generated drawing of the Alpha 
Magnetic Spectrometer (AMS). Credit: NASA

The MIT group leads an international collaboration of scientists that analyzed two and a half years' worth of data taken by the Alpha Magnetic Spectrometer (AMS), a large particle detector mounted on the exterior of the International Space Station, that captures incoming cosmic rays from all over the galaxy.

Among 41 billion cosmic ray events, instances of cosmic particles entering the detector, the researchers identified 10 million electrons and positrons, stable antiparticles of electrons.

Positrons can exist in relatively small numbers within the cosmic ray flux.

An excess of these particles has been observed by previous experiments, suggesting that they may not originate from cosmic rays, but come instead from a new source.

In 2013, the AMS collaboration, for the first time, accurately measured the onset of this excess.

The new AMS results may ultimately help scientists narrow in on the origin and features of dark matter, whose collisions may give rise to positrons.

"The AMS results announced today are tremendously provocative, and will drive scientists around the world to continue pursuing one of the biggest mysteries in the cosmos: dark matter," NASA chief scientist Ellen Stofan said at the agency’s headquarters in Washington.

"The clear and definitive data from AMS represent the caliber of scientific discovery enabled by our unique laboratory in space, the International Space Station."

"Today we are one step closer to answering the fundamental questions about how our universe works, and we look forward to many more exciting twists in this developing story."

AMS was constructed, tested and operated by an international team of 56 institutes from 16 countries and organized under the sponsorship of the U.S. Department of Energy's Office of Science.

NASA's Johnson Space Center in Houston manages the AMS Integration Project Office. AMS was launched on space shuttle Endeavour on May 16, 2011.

Operations on the space station began three days later. AMS continues operations aboard the station today.

More Information
"Electron and Positron Fluxes in Primary Cosmic Rays Measured with the Alpha Magnetic Spectrometer on the International Space Station" Phys. Rev. Lett. 113, 121102 – Published 18 September 2014 - 10.1103/PhysRevLett.113.121102

NASA MIT Alpha Magnetic Spectrometer (AMS): Prepares to release first results

The scientist leading one of the most expensive experiments ever put into space says the project is ready to come forward with its first results.

The Alpha Magnetic Spectrometer (AMS) was put on the International Space Station to survey the skies for high-energy particles, or cosmic rays.

Nobel Laureate Sam Ting said the scholarly paper to be published in a few weeks would concern dark matter.

This is the unseen material whose gravity holds galaxies together.

Researchers do not know what form this mysterious cosmic component takes, but one theory points to it being some very weakly interacting massive particle (Wimp).

Although telescopes cannot detect the Wimp, there are high hopes that AMS can confirm its existence and describe some of its properties from indirect measures.

The imminent publication in an as yet undetermined journal will detail the progress of that investigation.

The Massachusetts Institute of Technology professor said the project he first proposed back in the mid-1990s had now reached an important milestone.

"We've waited 18 years to write this paper, and we're now making the final check," he told reporters.

"I would imagine in two or three weeks, we should be able to make an announcement.

"We have six analysis groups to analyse the same results. Physicists as you know - everybody has their own interpretations, and we're now making sure everyone agrees with each other. And this is pretty much done now."

Sam Ting was speaking here in Boston at the annual meeting of the American Association for the Advancement of Science (AAAS).

His $2bn machine was taken up to the ISS in 2011 - on the final mission of Shuttle Endeavour.

The seven-tonne experiment holds a giant, specially designed magnet that bends the paths of particles that fall on it.

The way they bend reveals their charge, a fundamental property that, together with information about their mass, velocity and energy, garnered from a slew of detectors, tells scientists precisely what they are dealing with.

Prof Ting said that in its first 18 months of operation, AMS had witnessed 25 billion particle events.

ESA: Alpha Magnetic Spectrometer arrives at launch site

Looking down on the Alpha Magnetic Spectrometer (AMS-02) inside the Large Space Simulator in March 2010

One of the most exciting scientific instruments ever built, the Alpha Magnetic Spectrometer will arrive at the Kennedy Space Center.

The quest for discovering the composition of the Universe is about to take a step further on the International Space Station (ISS).

The Alpha Magnetic Spectrometer (AMS) is not only the largest scientific instrument to be installed on the Station, and the largest cryogenically cooled superconducting magnet ever used in orbit. It will be delivered to the ISS by NASA's Space Shuttle.

During the unloading of AMS, following arrival at the Space Shuttle Landing Facility, media will have the opportunity to have a look at the hardware and talk to AMS scientists and managers.

Simonetta Di Pippo, ESA Director of Human Spaceflight, and Prof. Sam Ting, the experiment's leader from the Massachusetts Institute of Technology, will be available for interviews.



Understanding our Universe
AMS will help us to understand the origin and structure of the Universe by searching for signs of antimatter and dark matter.

As a byproduct, AMS will also gather a host of information on stars and galaxies millions of light years from our home Galaxy.

AMS was built mostly by institutes in Italy, France, Germany, Portugal, Spain and Switzerland, together with the participation of China, Russia, Taiwan and US. In all, the experiment's team consists of 56 institutes from 16 countries.