A final test for AMS at ESTEC

The Alpha Magnetic Spectrometer (AMS) left CERN on Friday 12th February on the first leg of its journey to the International Space Station (ISS). The special convoy carrying the experiment arrived at the European Space Agency’s research and technology centre (ESTEC) in the Netherlands at 4.30 pm on Tuesday 16th February. AMS will then fly to the Kennedy Space Center in Florida before lifting off aboard the space shuttle.

Arrival of the AMS detector at ESTEC in the Netherlands (Credit ESA/Jari Makinen)

The transportation of an 8.5-tonne load filled with superfluid helium across Europe is no ordinary shipment. The AMS detector was first inserted into a supporting structure, specially built by the collaboration’s mechanical engineers, then surrounded by protective plastic foil, placed in a box and finally carefully loaded onto the special lorry also carrying a diesel generator running a pump to keep the helium at the right temperature (about
2 K). Its initial destination is ESA’s Research and Technology Centre (ESTEC), about 600 kilometres from CERN. Some 20 members of the AMS collaboration followed the detector on its journey, five of them in a car right behind the truck at a speed of 45 km/h. AMS’ journey took four days and was carried out by a German company that had already transported the AMS magnet and parts of the CMS detector.

While waving goodbye to the truck, the collaboration members who were busy preparing the special shipment for the last three days hoped never to see the detector at CERN again. Indeed, this will mean that AMS has received the “go-ahead” for the next leg to KSC.

Arrival in the clean room at ESTEC
(Credit ESA/Anneke de Floc'h)

At ESTEC AMS will be placed in ESA’s thermo-vacuum room that simulates space vacuum to test the detector’s capacity to exchange heat and thus maintain its thermal balance, which is essential to the functioning of the detector’s electronics and especially its unique superconducting magnet,  the first of its kind to be launched into space. If all goes well, towards the end of May the detector will embark on a journey to NASA’s Kennedy Space Center in Florida aboard a C5 aircraft owned by the US Air Force. There, it will prepare to board space shuttle Discovery, on its last-but-one flight (mission STS-134) before the programme is terminated by NASA. Lift-off is scheduled for July.

Once docked to the ISS, AMS will examine fundamental issues about matter and the origin and structure of the Universe directly from space. Its main scientific target is the search for dark matter and antimatter, in a programme that is complementary to that of the Large Hadron Collider. AMS data from space will be transmitted from the ISS to Houston, USA, and on to CERN, where the detector control centre will be located, and to a number of regional physics analysis centres set up by the collaborating institutes.
(Credit ESA/Anneke de Floc'h)

The AMS detector components were constructed by an international team with significant contributions from CERN Member States France, Germany, Italy, Portugal, Spain and Switzerland, as well as China and the USA. Assembly and testing with beam was carried out at CERN with help from the Laboratory’s engineering services. In particular, protons from the SPS were used to check the detector’s momentum resolution, thus confirming the spectrometer’s ability to measure particle curvature and momentum. AMS’s ability to distinguish electrons from protons was also tested at CERN. This is very important for the measurement of cosmic rays, 90% of which are protons and constitute a natural background for other signals that AMS scientists are interested in.

For further information about AMS arrival at ESTEC, please click here.

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by Paola Catapano