CDC structure

Shoji Uno (KEK) 　　　

July-8, 2009

Baseline Design

Belle

sBelle

Tentative drawing by Kohriki-san

Connection regions 1

Endplate and Outer cylinder Main and Conical (Backward)

Main and Conical (Forward)

Connection regions 2

ForwardBackward

Conical and Small cell

Small cell and Inner cylinder

Connection regions 3

Main parameters

Present FutureRadius of inner boundary (mm) 77 160Radius of outer boundary (mm) 880 1096Radius of inner most sense wire (mm) 88 168Radius of outer most sense wire (mm) 863 1082Number of layers 50 58Number of total sense wires 8400 15104Effective radius of dE/dx measurement (mm) 752 928Gas He-C2H6 He-C2H6

Diameter of sense wire (m) 30 30

Calculation of deformation and etc

• Deformation of Aluminum endplate– Thickness of endplate 　 10mm

• Tension of field wire 　 120g 80g• Gravitational sag, Sense : 190m(50g), Field:300m(80g)

– Unequal sag Nane-san’s talk

• Total tension ~4ton • Deformation Yamaoka-san’s talk 　 　　　

• Stress calculation – Thickness of outer cylinder 　 CFRP ： mm 　– Transition structure between endplate and outer cylinder– Bucking calculation for inner cylinder

• Larger tension for many wires ( ~400kg)

– Yamaoka-san’s talk

Weight

• Endplate 　– Al, Thickness : 10mm

– 110kgx2 = 220kg

• Outer Cylinder – CRRP, Thickness : 5mm

– 210kg

• Electronics Board– G10, 48ch/board

– 0.3kgx315 = 95kg

Wire configuration• So far, – 8(A),6(U),6(A),6(V),6(A),6(U),6(A),6(V),8(A), – 58 layers in total

• But,– Readout board 64ch/board 16x4 No good assignment

• 48ch/board 16X3– 8(A) 2(A)+6(A) inner most super layer

• 2(A) special treatment 160x2=320 : 48x7=336

– 8(A) 6(A) outer most super layer

– 56 layers in total Good assignment

• Other good idea is highly welcome.

Readout board space

Test board 16ch 48ch(~300boards in total)

20cm

17.5

cm

Should be fit in volume

My Personal Plan for Construction