Johnson Space Center is home to the Alpha Magnetic Spectrometer (AMS) Project Office. The AMS-02 experiment is a state-of-the-art particle physics detector being constructed, tested and operated by an international team composed of 60 institutes from 16 countries and organized under United States Department of Energy (DOE) sponsorship. The JSC project office oversees and directs the overall payload integration activities and ensures that the payload is safe and ready for launch on the Space Shuttle and deployment onto the ISS. The AMS Experiment will use the unique environment of space to advance knowledge of the universe and lead to the understanding of the universe’s origin.
The AMS is a high profile space-based particle physics experiment that is led by Nobel laureate Samuel Ting of the Massachusetts Institute of Technology (MIT).
Figure 1: AMS-01 on STS-91
The AMS flew in space in June of 1998 aboard the Space Shuttle Discovery (Figure 1), and it is being integrated and tested to fly on the International Space Station (ISS). The AMS-02 will be transported in the cargo bay of the Space Shuttle for installation on the ISS. Once on the ISS S3 Upper Inboard Payload Attach Site, the AMS will remain active for the duration of ISS (Figure 2).
Figure 2: AMS-02 on S3 Truss of ISS
Orbiting the Earth at an altitude of 200 nautical miles, the AMS is pioneering a new frontier in particle physics research for the 21st century. This unique scientific mission of exploration seeks to understand fundamental issues shared by physics, astrophysics and cosmology on the origin and structure of the Universe. Although the AMS is specifically looking for antimatter and dark matter, as the first magnetic spectrometer in space, AMS has and will collect information from cosmic sources emanating from stars and galaxies millions of light years beyond the Milky Way. The technical challenges to build such a detector for use in space have been surmounted through the close collaboration of the AMS scientists and industries around the world whose efforts have resulted in the development of new technologies and higher standards of precision.
The experiment (Figure 3) utilizes a large permanent magnet to produce a strong, uniform magnetic field (~0.14 Tesla) over a large volume of ~1m3. The magnetic field is used to bend the path of charged cosmic particles as they pass through five different types of detectors. The Transition Radiation Detector (TRD) measures particles passing at speeds nearly that of the speed of light. The Time of Flight (TOF) measures the charge and velocity of passing particles. The Silicon Tracker measures the coordinates of charged particles in the magnetic field. The Ring Image Cerenkov Counter (RICH) measures both the velocity and charge of the particles and the Electromagnetic Calorimeter (ECAL) measures the energy and coordinates of electrons, positrons and gamma rays. Figure 1 shows the AMS detector and its response to different particles or nuclei. The AMS also employs two star trackers and a GPS system. With over 300,000 data channels, the detector gathers an extremely large amount of data which is then processed and sent to Earth utilizing the ISS power, communication and data infrastructure.
Figure 3: AMS-02 Detector During Integration in Geneva
Search for Antimatter
Figure 4: Studying Universe and Anti-Universe (Data Courtesy of MIT)
Figure 5: AMS-02 Antihelium Limits (Data Courtesy of MIT)
Search for Dark Matter
Cosmic Ray Measurement
Figure 6: Cutaway view of the AMS detector (left). Response of the detectors layers to a charged particle of energy 0.3 TeV (Data courtesy of MIT)
Figure 7: AMS-02 Identification and measurement potential (Data courtesy of MIT)