Transcript CDC Structure

CDC Structure
S. Uno
KEK
2009.3.18
Endplate Design
sBelle
350mm
250mm
300mm
Wire stringing
• Vertical stringing with outer cylinder.
– Human can stand inside the chamber and can
touch the wire.
• Inner diameter without the small cell part : ~500mm
• N. Taniguchi confirmed it with a hand-made mockup.
– Stringing with tension can be done from outer
layer.
• Two-way method ( Belle-CDC ) is not necessary.
Barrel PID
Backup
CDC structure
Shoji Uno (KEK)
Dec-3rd, 2008
Baseline Design
sBelle
Belle
Main parameters
Radius of inner boundary (mm)
Radius of outer boundary (mm)
Radius of inner most sense wire (mm)
Radius of outer most sense wire (mm)
Number of layers
Number of total sense wires
Effective radius of dE/dx measurement (mm)
Gas
Diameter of sense wire (mm)
Present
77
Future
160
880
88
863
1140
172
1120
50
8400
752
58
15104
978
He-C2H6 He-C2H6
30
30
Wire Configuration
250 mm
Present CDC
New CDC
250 mm
1200 mm
Small Cell Drift Chamber
Photo of small cell chamber
Just after wire stringing
Installation in 2003 summer
Curved Endplate
• Deformation of endplate due to wire
tension was calculated at design stage of
present Belle CDC (Total tension: 3.5 Ton).
Deformation(mm)
35.2
2.03
1.31
Present
New
Weight
• Endplate
– Al, Thickness : 10mm (12mm)
– 110kgx2 = 220kg (264kg)
• Outer Cylinder
– CRRP, Thickness : 5mm
– 210kg
• Electronics Board
– G10, 48ch/board
– 0.3kgx315 = 95kg
Present support
Calculation of deformation and etc
• Deformation of Aluminum endplate
– Thickness of endplate 10mm  12mm
• Deformation 1/t3
– Tension of field wire
1  0.58
120g  80g
• Gravitational sag, Sense : 120mm(80g), Field:300mm(80g)
• Total tension 4.8ton
• Stress calculation
– Thickness of outer cylinder CFRP：mm
– Transition structure between endplate and outer
cylinder
• Support structure
• Structure for wiring jig
– Simpler one as compared with Belle-CDC
• Etc.
Wire stringing
• Now, I am thinking a vertical stringing, not
horizontal.
– Once, I thought the horizontal stringing
• Vertical stringing with outer cylinder.
– Human can stand inside the chamber and can
touch the wire.
• Inner diameter without the small cell part : ~500mm
• Inner diameter of present transition cylinder :
580mm
– Stringing with tension can be done from outer
layer.
• Two-way method ( Belle-CDC ) is not necessary.
Installation
• Removing and installation
can be done using similar
small bar in horizontal
direction.
Cathode installation
in vertical direction
CDC installation in horizontal direction
My Personal Plan for
Construction