The morning of 27 November was exciting for the ATLAS team at DESY. They reached a major milestone in the construction of an endcap for the new silicon strip detector for the ATLAS experiment at CERN in Geneva. The basic mechanical structure of the endcap (the “skeleton”), which is made of carbon fibre and was built in Amsterdam at the Dutch national particle physics facility NIKHEF, was delivered to the Detector Assembly Facility (DAF) at DESY in Hamburg.

The company Hasenkamp was hired for this important transport. In addition to transporting art worldwide, the company also specialises in the transport and handling of highly sensitive technical equipment and experimental set-ups from the technology areas of research and development. For the transport of the ATLAS endcap, they developed a special box (3 m x 3 m x 3.5 m) that is insulated on the inside with 8.5-cm thick material developed for space travel. The box, which had a total weight of 1800 kg, can hold the same temperature and humidity level for up to 72 hours, so that no active cooling would be required for the transport. The box was surrounded by 12 dampeners that would absorb all possible shocks along the way. A “superframe” that was developed at DESY held the skeleton. This superframe will accompany the endcap until it is installed in the ALTAS experiment at CERN, and is equally complex as it can turn the entire endcap as well as slide it into the experiment itself.

But why is there so much effort in transporting what amounts to only a skeleton? For one, it is extremely sensitive, in that it is composed of only carbon fibres and cannot handle even the smallest of deformations. The transport was also a trial for an even more sensitive cargo: the finished endcap, which in about three years will need to be moved from DESY in Hamburg to CERN on the Swiss–French border. In order to simulate the conditions of this transport as accurately as possible, the skeleton was specially equipped with imitations of the sensors and other components for its current journey, which are similar in weight to the later real components. Sensors recording temperature, humidity, and vibration were installed on the skeleton as well as the palette supporting it. Their values will give the team important information as to whether or not the current setup will suffice for bringing the finished endcap to CERN. The endcap will need to be stored at a constant temperature of 20°C and a low humidity of less than 40%.

“This was an exciting part of the project – we learned a great deal. Ninety-nine percent of the task went perfectly, but we’ve taken note of a manoeuvring critique made the following morning that we will improve on next time,” says DESY engineer Volker Prahl. Prahl and other DESY colleagues were also at NIKHEF for the packing of the skeleton in order to double-check all details of the package design.

Now, a few days later, the skeleton has been moved into the huge cleanroom of the DAF itself. There, it will be transformed over three years from a completely mechanical structure to a completed detector with around 35 m² of silicon and many other components. Then Hasenkamp will return and both the DESY endcap as well as its sister to be built at NIKHEF will be brought to CERN.