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Cooling System

Requirement:

The temperature gradient on the wafer has to be held to less than 0.3 C.

Justification:

Physics simulations show position resolution degradation above 0.3 C

Status:

The wafer implants were chosen to not exceed the required gradient. An air cooling system was designed to carry away on detector heat due to ambient temperature, leakage current and electronics. A water cooling system was chosen to cool the electronics to a constant operating temperature.

Requirement:

The electronics have to operate at a constant temperature near room temperature

Justification:

Uncooled electronics heats up to 80 C in a short time interval. The performance becomes erratic at these temperatures. Very high temperatures on the EC also affect the wafer on the DC.

Status:

After thorough evaluation of three options (water, evaporative and air cooling), the group decided to design a water cooling system.

Requirement:

The cooling system has to meet the radiation length requirements

Justification:

physics simulations

Status:

The present design leads to an average radiation length of 3.2% for the completed SVT.

Requirement:

The water system has to allow a Be structure and it should be leakless.

Justification:

The Be structure is the most rigid structure with the least radiation length. The water has to be treated to avoid oxidation. An under pressure system is a standard configuration to prevent detector malfunction due to water leaks.

Status:

A leakless water system with special water purifiers and heat exchangers has been developed.

Requirement:

A water manifold system has to be integrated to the detector.

Justification:

Water manifolds ease the water supply to the distributed water cooling system.

Status:

The water is being supplied from one side of the detector and flows out to the other side. The two manifolds also host the HV divider boards for each ladder. The radiation length of the two manifolds was optimized to allow physics measurements at forward rapidities.



next up previous
Next: Assembly Up: Mechanical Previous: Support Structure



Claude Andre Pruneau
Thu Oct 12 17:29:54 EDT 1995