Operating modes of the SSC sector station cryogenic system

Conference · Sat May 01 04:00:00 EDT 1993

OSTI ID:10170145

Ganni, V; Abramovich, S; Apparao, T V.V.R.

The magnets in the Collider rings and in the HEB (High Energy Booster) ring are refrigerated by single phase helium flow controlled at a temperature of 4 K to maintain the magnet windings in the superconductive state. To minimize the heat load into the 4 K loop, the magnet cryostats are designed to provide high quality thermal insulation achieved by a high vacuum with multilayer insulation and by two thermal shields at a nominal temperatures of 84 K and 20 K, respectively. An extensive cryogenic system capable of normal operation of the superconducting magnets and handling transient conditions such as quenches, beam activation, ring filling, and beam ramping is required. The cryogenic system must also have the capability to perform other services such as cleanup, cooldown, and warmup, to allow for maintenance and repair of the superconductive components throughout the ring. The refrigeration system is designed with a specific capacity to meet each of the various loads viz. 4 K refrigeration, 4 K liquefaction and 20 K shield cooling, to meet all the loads during normal and upset conditions and possess some extra capacity. The static heat leak and dynamic load to the 4 K components are the 4 K refrigeration load. It is handled by the latent heat of vaporization in the helium recoolers. The 4 K helium used for cooling the electrical leads returned at 300 K to the refrigerator, is the liquefaction load. The 20 K shield that absorbs part of the radiation and the static heat leak above 20 K is the 20 K refrigeration load. This load is handled by supplying 200 g/s, 3.0 bar helium at 14 K and returns the helium to the refrigerator at a temperature depending on the load. The refrigeration system has one spare compressor. It is capable of delivering 4 K and 20 K refrigeration and part of the liquefaction load in the nominal mode of operation even when any one of the expanders fail. This paper summarizes the operating modes of the SCS, the various states and processes.

• Research Organization: Superconducting Super Collider Lab., Dallas, TX (United States)
• Sponsoring Organization: USDOE, Washington, DC (United States)
• DOE Contract Number: AC35-89ER40486
• OSTI ID: 10170145
• Report Number(s): SSCL-Preprint--297; CONF-930537--83; ON: DE93016895
• Country of Publication: United States
• Language: English

Related Subjects

43 PARTICLE ACCELERATORS
430303
CRYOGENICS
EXPERIMENTAL FACILITIES AND EQUIPMENT
OPERATION
QUENCHING
SPECIFICATIONS
SUPERCONDUCTING MAGNETS
SUPERCONDUCTING SUPER COLLIDER