Near Detector Racks Page

Rack Labels 270k, 97sec @ 28.8kbps
Side view of the detector and racks, with the racks labeled as to their content. FE = Front End; M = Master digital readout, interface to DAQ; HV obvious; Pulser boxes are in some M racks. The DAQ/DCS racks are upstream of the stairs.
Rack Locations 240k, 86sec @ 28.8kbps
Side view of detector and racks, with rack spatial locations shown. Locations are relative to the center of the 1st detector support post

The cabling model, on Stand 4
A plane on the cart fixture, view 1 and view 2. The platform allows access to the connectors on V planes, whose module snouts are along the top and upper corner
Rack work area
a Front-End rack prototype, with 2 shelves of Alner boxes and 2 FE electronics crates
a different Front-End rack prototype, used for water plumbing design, holding 2 water-cooled Alner box shelves and 2 models of heat exchangers
close up of water-cooled heat-sink shelf, with Alner boxes
a Master rack, with Master electronics crate and LI crate

A Front-End (FE) rack holds Alner boxes and the QIE-based electronics which digitizes the phototube signals. There are 26 FE racks. The Alner boxes are placed within a rack so that their fiber cable side is flush with the back of the rack; four Alner boxes fit across the rack back opening. Each FE racks holds two such shelves of 3 or 4 Alner boxes, at two different elevations. The metal shelves have cool water piped just below them, to keep the temperature of the Alner Boxes constant. The QIE-based electronics sit in a 6u VME crate. One crate serves up to 4 phototubes, so there are two of these crates per FE rack. Water cooling units are placed around the crates and their power supplies to cool the air warmed by the electronics; these racks do not dump their heat to the air of the Near Hall. A protoype FE rack was made in mid-2001, on which air flow studies were done. New prototyping is expected in winter '02 and spring '03.

Master Racks

A Master rack holds one 9u VME Master crate, which holds the Master boards. The Master Boards collect data words from FE crates and format them for the DAQ. There are 8 Master racks. Three of these racks will also hold LED Pulser system crates.

Other Racks

Other racks in the system are: 2 High Voltage racks, each holding one 1440 HV distribution system; 1 Clock Rack holding the central clock and the distribution system which fans the clock signals out to all FE and Master racks; DAQ racks, holding the main DAQ components; the DCS system rack, which may also hold the ACNET crate which receives timing signals from the Main Injector; an ethernet distribution rack. Of these, only the HV and Clock racks sit alongside the detector, all the others sit on the floor in front of the detector, along the west wall.

Near Detector Racks

Page update in progress

Rack Location Schematic Diagrams

Master Racks

Other Racks