Design, manufacture, inspection, transport, installation, and test of the XFEL Main-, Shaft-, and Bypass Transfer-line
In the coming years a new project called European X-ray Free Electron Laser (XFEL) will be constructed at DESY, Hamburg. The purpose of the project is to produce high intensity coherent X rays with true laser properties. The wavelength of these rays is comparable to the atomic dimension. This opens new possibilities in basic science and medical diagnostics, as well as in industrial research and development.
The X-rays will be produced by free electrons accelerated to energies of around 17 GeV by means of 1.3 GHz superconducting cavities cooled down to the temperature of 2 K. Each cavity consists of 9 niobium RF-resonators or cells. Eight cavities, each of 1.038 m length, together with one superconducting magnets assembly are placed inside a cryostat with double thermal shields at 5-8 K and 40-80 K creating one accelerator-module of 12 m length. In total, about 100 such modules are required for the XFEL and will be installed in a tunnel starting from the injector building on the DESY site and running towards the town Schenefeld. Two cold boxes of the existing HERA refrigeration plant are used, after a major conversion to the XFEL refrigeration plant, for the cryogenic supply of this chain of modules. The 2K helium bath in the cavities is achieved by reducing the vapour pressure to 30 mbar in this circuit by means of cold compressors placed in a 2K cold box in the second underground floor of the entrance shaft (XSE) of the injector building. The 2K cold box is connected to the XFEL refrigeration plant via a 7 fold transfer line called XFEL Main Transfer Line (XRTL) of approximately 180 m length. This line contain the pipes for the two shield circuits as well as the supply for the 2K bath, the pumped flow from the cold compressor and the return line of a 4K subcooler bath. The process pipes of the XRTL are enclosed by an 80 K thermal shield. From the 2K cold box the cryogenic supply is distributed to the injector and the cold linac by means of a distribution box XLVB.
The accelerator modules in the XFEL tunnel XTL are connected to the XLVB via a Feedcap, and a 6 fold transfer line called XFEL Shaft Transfer Line (XLTL1). The transfer line XLTL1 contains the process pipes for the two shield circuits as well as the supply for the 2K bath and the pumped flow to the cold compressor. The process pipes of the XLTL1 are enclosed in an 80 K thermal shield and additionally in an 8K thermal shield to further reduce the heat load of the 2K lines. It has a length of approximately 76 m.
The accelerator modules in the XFEL tunnel XTL are arranged in three groups called “L1”, “L2” and “L3”. In the space between these groups of superconducting accelerator modules special components which are operated at room temperature like bunch compressors are installed. To supply the subsequent chains of modules “L2” and “L3” with cold helium transfer lines bypassing the warm components on the beam axis are connecting the endcap of the preceeding chain of modules with the feedcap of the following (XLTL2 with a length of app. 60m and XLTL3 with a length of 88m).
The Bypass transfer lines XLTL2 and XLTL3 are of the same construction as the Shaft transfer line XLTL1.
The above mentioned vacuum isolated, thermal shielded, multiple process pipe transfer lines XRTL, XLTL1, XLTL2 and XLTL3 are topic of this call for tenders
Deadline
Die Frist für den Eingang der Angebote war 2013-05-03.
Die Ausschreibung wurde veröffentlicht am 2013-03-13.
Anbieter
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Geschichte der Beschaffung
| Datum |
Dokument |
| 2013-03-13
|
Auftragsbekanntmachung
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| 2013-08-20
|
Bekanntmachung über vergebene Aufträge
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