CMS Phase I ODU Upgrade
CMS
Compact Muon Solenoid (CMS) is a detector attached to the Large Hadron Collider (LHC) at CERN. CMS studies the products for proton proton collisions, that simulate the very early universe by colliding two beams of protons, moving a high enough speeds to have the same amount of energy as an aircraft carrier moving at about five miles an hour.
The detector is made with many layers of detection, starting with a silicon tracker. The next layer is called the ECAL (Crystal Electromagnetic Calorimeter), followed by the HCAL (Hadron Calorimeter).
The solenoid is made from superconducting wire, is 7 m in diameter and 13m long. The solenoid produces a magnetic field that is 100,000 times stronger than the earths field.
Optical Decoder Units
The HCAL is made up of layers of scintillator in a brass support structure. The brass not only supports the scintillator it slows the particles down. Due to the size of the detector the scintillator is a large sheet of plastic. As these sheets would be to big to yield useful data each sheet (Megatile) is scored almost all the way through to turn it into a grouping of tiles. Wave shifting fibers are imbedded near the perimeter of each tile, and a cable comes off each megatile on it's way to be digitized. In order to make the signal
Production
To make the ODUs we start with a the patch plate (Figure 1). Calibration fibers are added to the patch plate
(Figure 2), then each channel of calibration fibers is separated and placed in a holder (Figure 3) to prepare for the weaving process.
Figure 1
Figure 2
Figure 3