BSC Mechanics
Alan Bell, Rob Knegjens & Mark Hashimoto
PMT Box Positions & Mounting
• Proposed position of PMT
boxes….
• Brackets need to allow
some movement for
alignment with magnetic
field
BSC Mechanics - Alan Bell. Mark
Hashimoto, Rob Knegjens
2
PMT Box brackets - proposal
Coordinates:
X = 1.3m-1.7m
Y = 1.4m-1.7m
Z = 11.3m-12.3m
Will place PMTs in a B
field of 100 – 170Gauss*
~ < 1° *
* based on simulations
BSC Mechanics - Alan Bell. Mark
Hashimoto, Rob Knegjens
3
PMT box volume magnetic field
BSC Mechanics - Alan Bell. Mark
Hashimoto, Rob Knegjens
4
PMT Box Modifications - proposal
•
‘Cables’ in per box…
–
–
–
•
Optical fibres
LED drive RG58 coax cable x 1
HV Cable
‘Cables’ out per box…
–
RG58 coaxial signal cables x 9
Radial HV connector
10 x BNC connectors on opposite
face for signal outs & LED drive in
Optical fiber bundles
BSC Mechanics - Alan Bell. Mark
Hashimoto, Rob Knegjens
5
HF Grooves – seeking approval
•
•
•
Minimum acceptable bending
radius of fibers = 60mm.
Dmitry’s drawings based on 80mm
radius.
Allows pairs of optical fiber groups
to exit HF face separated spatially.
–
•
•
Cherenkov radiation concerns
Is 10cm separation enough?
What particles/jets do we expect
in this region (z = ±10.9m)?
BSC Mechanics - Alan Bell. Mark
Hashimoto, Rob Knegjens
6
Other tasks
• Once PMT box positions have been approved by BRM group…
– Get clearance from HF Group
– Write up detailed work package & present to Martin Gastal
– Accurately measure optical fiber lengths required and prepare fibers for
installation
– Calculate Nitrogen pipe lengths & paths. Order pipe & fittings from Christoph
Schaefer
– Detailed path of cable (pipe) trays submitted to Martin Gastal
– Lay extra HV cable on nearside of HF via HF cable tray
– STILL going round in circles with Radiall connectors. CERN Stores and
Precimation (Suisse) are not communicating.
– Contacting Precimation France.
BSC Mechanics - Alan Bell. Mark
Hashimoto, Rob Knegjens
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