Technical Design Report Super Fragment Separator

DRAFT
The first refrigerator, Cryo1, will have a nominal refrigerating capacity of 4.2 kW. During normal
operation of the new facility this plant will supply the Super-FRS and all equipment installed in the
southern part of the FAIR facility. Cryo2 will supply the synchrotrons (SIS 100 and SIS 300) and
parts of the HEBT. The series and string test facility will be supplied by CryoST (Cryo Series
Testing). For the high number of small experiments or single small consumers liquid helium will
be provided in the central helium supply depot by a separate liquefier CryoHeSu (Cryo Helium
Supply).
The two refrigerators Cryo1 and Cryo2 will be interconnected by a cold connection to support one
another as required. One plant will be sufficient to keep all the cold masses below 80 K during
shutdowns.
Cryo1 and Cryo2 will share a common compressor station to increase reliability and to avoid two
buildings with the very specially demands for a compressor building as noise and vibration protection,
maintenance tolls (cranes, etc.), oil-resistant floor covering and groundwater protection.
2.4.A4.2.2 Heat Load for the Refrigerators
For the design of the refrigerators the heat loads with the corresponding temperature levels are
required. The nominal working temperature for both plants will be 4.4 K at 1.2 bar. The refrigerators
will distribute high pressure liquid helium (3.0 bar, 4.6 K) to every user. Each user can
operate the local cooling circuit with bath (Super-FRS) or forced flow cooling (two-phase for the
SIS 100, one-phase for the SIS 300). The refrigerator supplies only liquid helium and receives low
pressure gaseous helium in return. The return gas flow will be:
• at 4.4 K in case of the magnet cooling return line,
• at ambient temperature in case of current lead cooling.
Conventional current leads require that the refrigerator provides liquid helium and gets back
gaseous helium at ambient temperature. This refrigeration service is called liquefaction.
The refrigerators will also supply a helium cooling stream from about 50 K for the cooling of
thermal shields and for the cooling of high temperature superconductor (HTS) current leads. The
return flow will have a temperature of 80 K.
Table 2.4.34 gives the sum of head loads for different consumers [105,106] splitted into the different
refrigerators.
Table 2.4.34: Heat loads for FAIR (including safety factor).
Plant Consumer Heat load [kW]
Cryo1 Further Consumers 0.23
Super-FRS 1.40
Experiments 0.17
SIS 100 1.0
4.19
Cryo2
Further Consumers 1.91
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