Gain Monitoring System

1
Gain Monitoring System

• 2008 13th Jun. Fri.
• Kobe Univ.
• Hiroko Ikeda

2
Ideas

• Fiber (connected to the acrylic plate with
  optical cement) distribution.

• Side-emitting fibers
• Optical fibers with notches

I have tested above 3 methods to decide which one
we will adopt for the FNAL beam test.
3
Setup

• ?. Fiber distribution (with acrylic plate)

Acrylic plate(27cm long)
Acrylic plates (0.8mm thick)
Hole(1.1mmf)
4
Fiber distribution
?1 fiber (on bundle1) ?1 fiber (on bundle2) ?2
fibers (on bundle2)

• 0.02

Dark noise level (0.02p.e.)
5
?.ESKA (side-emitting fiber f0.8 mm)
28mm
?. Optical fiber (with notches)
Notch made with a file
6
Comparison
?acrylic plate ?ESKA1 ?ESKA2 ?optical fiber
with notches
Dark noise level (0.02 p.e.)
7
Proposed setup for the FNAL BT

• ? ESKA Only

ESKA
? ESKA and optical fiber
Optical fiber
ESKA
8
Summary Plans

• Either ESKA or notched optical fiber are likely
  candidates for the gain monitoring system.
• To do (within a few days)
• Check connection between fiber and hole for
  fiber.
• Examine position dependence of ESKAs light
  decrease.
• Then we will decide the light distribution method
  and whole design of the system.

9
Try covering first half of acrylic bar
?w/o light shield ?w/ light shield