Washington - The first published results from the Alpha Magnetic Spectrometer (AMS), a major physics experiment operating on the International Space Station, has been announced.
The result is the most precise measurement to date of the ratio of positrons to electrons in cosmic rays.
Measurements of this key ratio may eventually provide the world with our first glimpse into dark matter.
The AMS experiment, developed under the leadership of Nobel Laureate Samuel Ting, with support from the US Department of Energy and fifteen other international partners, is the worldâ€™s most precise detector of cosmic rays.
It was constructed at universities around the world and assembled at the European Organization for Nuclear Research (CERN).
â€śWe are very excited with this first result from AMS,â€ť James Siegrist, DOE Associate Director of Science for High Energy Physics, said.
â€śWe look forward to more important results in the future.â€ť
â€śThis result is the first step, the beginning of a series of high precision experimental results from the Alpha Magnetic Spectrometer. This shows that a large international particle physics collaboration can work together to do particle physics in space,â€ť Professor Ting said.
The science goals of AMS include the search for dark matter, antimatter, and new physical phenomena.
The detector provides high-precision measurements of cosmic ray particle fluxes, their ratios and gamma rays.
This first physics result from AMS is based on 18 months of operation, during which time AMS measured 6,800,000 cosmic ray electrons in the energy range of a half-billion to a trillion electron volts, and over 400,000 positrons (positive electrons), the largest number of energetic antimatter particles directly measured from space.
The importance of this measurement is that it could eventually provide a â€śsmoking gunâ€ť that certain dark matter particles exist and that dark matter particles and antiparticles are annihilating each other in space.
Although the data do not show a â€śsmoking gunâ€ť at this time, this first high-precision (~1 percent error) measurement of the spectrum has interesting features not seen before that future data may help clarify.
With additional data in the coming years, AMS has the potential to shed light on dark matter.
AMS was installed on the Space Station on May 19, 2011 after having been brought into orbit on the last flight of NASAâ€™s space shuttle Endeavour under the command of Captain Mark Kelly.
Within only hours of its installation on the exterior of the Space Station, AMS became fully operational, and to date has measured over 30 billion cosmic ray events.