April 18th, 2010

Last Friday, the results of the EMC and TV test of AMS were discussed during the Technical Interchange Meeting. All detector subsystem performed well during the various phases of the TVT. During the TV test the Superconducting Magnet endurance has been determined to be about 20 months. Since ISS operations will be extended from 2015 to 2020, it appears that the Superconducting Magnet could only operate for a small fraction of an extended 10 years data taking of AMS-02 on the ISS.

The Permanent Magnet option has also been extensively reviewed: in particular it has been shown that by relocating part of the existing silicon tracker the detector performances at high energy are unchanged at a cost of a small loss in acceptance, loss which is quickly recovered by running the experiment for a longer period of time. The gain in physics sensitivity has been estimated to range between a factor of 3.5 below 500 GeV to a factor of 2 in the interval from 500 GeV to 1 TeV, in favor of the Permanent Magnet solution operating for 10 years.

By the end of the meeting, the common consensus has been towards supporting the Permanent Magnet configuration. The implementation and integration of the Permanent Magnet solution will be done at CERN in time for a shipment to KSC by the beginning of September 2010.