Alpha Magnetic Spectrometer (AMS) Experiment: Search for the origin of anti-matter in the Universe

AMS was installed on board the ISS in 2011. It is the only large aperture magnetic spectrometer in space capable of searching for antimatter in the Universe. It has collected over 150 billion cosmic ray events far exceeding the total observed events in the past 100 years. AMS had discovered a new source of anti-electron (known as positron) in space. Its precision observation had revolutionized our understanding of cosmic ray. It has observed 8 candidate anti-helium events which would be a breakthrough discovery if verified.

ASGC has been supporting AMS data analysis by DiCOS since 2012. In addtion, ASGC also support the data reproduction required from time to time due to the upgrade of the reconstruction software as well as the huge simulation events needed to search for anti-deuterium, anti-helium, anti-carbon and anti-oxygen for understanding the origin of antimatter in the Universe.

Contributions of ASGC:

1. The fully automated production workflow is implemented by DiCOS at ASGC

   – Job acquiring, submission, monitoring, validation, transferring, and (optional) scratching

2. Parallelization of reconstruction and simulation over distributed cloud environment

3. Memory optimization for Geant4

4. Performance Gain

  – 30-50% increase of reconstruction productivity

  – 50x shorter reconstruction time per run and calibration job execution time

  – 5x reduction to the total memory consumption per core of simulation job