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Electrical Cables from the SVT Racks to the SVT Readout Electronics or passed through the Readout Electonics to the SVT Carriers or Carrier Interfaces

Requirement:

The required CABLES to each of the 24 READOUT ELECTRONICS locations are listed in Table I. The total number of CABLES required is 24 times the numbers in Table I. The cross sectional area of the bundle of CABLES that runs from the RACKS to each of the 24 READOUT ELECTRONICS LOCATIONS (11 CABLES) is 3.0 .

  
Table: CABLES required from SVT RACKS to each READOUT ELECTRONICS locations or passed through READOUT ELECTRONICS to CARRIERS OR CARRIER INTERFACES. There are 24 READOUT ELECTRONICS locations on the TPC end caps. 12 are on right side and 12 are on the left side. The HIGH VOLTAGE CABLES pass through the READOUT ELECTRONICS locations, through the SVT SUPPORT STRUCTURE, to HIGH VOLTAGE DIVIDER BOARDS near the ends of the SVT LADDERS. The CALIBRATION CABLES pass through the READOUT ELECTRONICS locations, through the SVT SUPPORT STRUCTURE, to the CARRIER INTERFACES. All CABLES are plenum rated.

Justification:

THE SVT LOW VOLTAGE power supplies, HIGH VOLTAGE power supplies, TRIGGER/CLOCK distribution point, SDD CALIBRATION-source electronics, and the SLOW CONTROLS system are located in the RACKS. Electrical CABLES must connect these systems to the SVT READOUT ELECTRONICS, the CARRIERS, and the CARRIER INTERFACES.

The SVT contains 36 ladders. Near the water manifolds close to both ends of each ladder are voltage DIVIDER BOARDS. A separate HIGH VOLTAGE line connects to each DIVIDER BOARD, so that a total of 72 HIGH VOLTAGE lines is needed. Since there are 24 READOUT ELECTRONICS locations at each TPC endcap, 3 HIGH VOLTAGE lines from the RACKS through each of the 24 READOUT ELECTRONICS locations are required. The HIGH VOLTAGE lines pass through the READOUT ELECTRONICS locations, through the SVT SUPPORT STRUCTURE, to DIVIDER BOARDS located near the ends of the SVT LADDERS.

[From each DIVIDER BOARD a flex cable with 50 voltage levels runs to the first detector on its side of the ladder. Each detector has about 500 cathodes, and each 10th cathode is supported externally. The voltage lines are then daisy chained to the other detectors on the ladder. The actual number of Silicon Drift Detectors associated with each of the 72 HIGH VOLTAGE lines is 2, 3, or 4. The number of 50-line HIGH VOLTAGE distribution cables from the water manifolds to the ladder is 72.]

Each SDD requires 6 CALIBRATION signals. A total of 72 -- (6 shielded pair) CABLES are required. Each cable goes to one end of each ladder and the 6 CALIBRATION signals are daisy chained to either 2, 3, or 4 SDDs on that end of the ladder. Since there are 24 READOUT ELECTRONICS locations (12 on each TPC endcap), 3 CALIBRATION signal lines are routed from the RACKS through each of the 24 READOUT ELECTRONICS locations, through the SVT SUPPORT STRUCTURE, to the CARRIER INTERFACES.

Each READOUT ELECTRONICS location requires LOW VOLTAGE power for POWER CONDITIONERS that generate -1,+4, +5A, +5D, +12, -12 VDC for use by the READOUT ELECTRONICS and the HYBRIDS. These 6 voltages will be provided to each READOUT ELECTRONICS location using 2 -- (4-conductor) cables from power supplies in the RACKS. [The additional 2 conductors are for 2 grounds (A&D).]

Each READOUT ELECTRONICS location requires 1-(4 shielded pair) from the CLOCK/TRIGGER distribution tree.

Each READOUT ELECTRONICS location requires 1-(4 shielded pair) to interface the READOUT ELECTRONICS to the SLOW CONTROLS (HDLC).

In addition 1--(8 shielded pair) should be provided to each READOUT ELECTRONICS location for SPARE, SAFETY, INTERLOCK, ETC., purposes.

NOTE: A multi-conductor (number of conductors to be determined) must connect one of the RACKS to the Capacitive Displacement Measuring System (CDMS) located on the SVT ladders.



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Next: Electrical Cables from Up: Space Previous: Executive Summary



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