The cartridge is a cilindrical device designed to support one complete FPD detector and photomultipliers and to insert the detector inside the Roman Pot.
Basicaly it has three major parts:
1) One small (3" x 1 1/2" x 2 3/4") aluminun opened box. It will hold and protect the plastic detector;
2) One aluminum long tube (3 1/2" O.D. x 9 1/2" long). It will hold the box and it will protect and guide the optical fibers to the photomultipliers.It will fit inside the castle piston;
3) One big cilindrical split case (8 1/2" O.D. x 11" long). It's a light tight case that will hold and position the fiber optics terminations ("cookies") and all photomultipliers (7 small multianode PMTs around a larger central PMT).
The cartridge is a light tight, two diameter tube that will hold the detector at one end and will enclosure the photomultipliers at the other end.
The small diameter tube is about 9" long and it holds the detec- tor box by a flexible silicon rubber interface. This tube slides and fits inside the piston plunger assembly of the roman pot. It guides and protects the bundles of fibers from the detector to the MAPMT too. There is enough clearance between the tube end and MAPMT's socktes in order to minimize stress on fibers and cookies due to bend radius.
The larger diameter tube is a split tube with two parts. The part connected to the small diameter tube can slide along this tube in order to make an easy assembly. In normal use it is fixed to the end of the tube. That part holds a round plate between two rings. The first (left) ring is permanentely fixed to the tube wall, and the second ring is a spacer and can be removed for the assembly process. The round plate has six thru square holes and one thru round center hole.These holes fit the Photomultipliers sockets. The tube ends on a rmovable lid which sup- ports the cable connectors.
The other large diameter part holds all Photomultipliers and provides the housing for the inboard electronics. The PMT's are suppor- ted by a molded silicon rubber cushion between two spaced compress round plates. This cushion is intended to guarantee an easy alignment of PMT's with sockets and to avoid excessive load pressure to the PMT's window.
The detector is fixed to the bottom of the window assembly by a long end thread rod and a compress tube around this rod. One end of the rod is screwed to the alignment pin on the window assembly and the other end is screwed to a cilindrical nut which pushes the compress tu- be against the detector. The cilindrical nut and the tube lie in a hole inside the round center socket and they can slide freely but the nut doesn't touch the PMT glass window.