svd mechanics markus friedl (hephy vienna) bpac, 26 october 2015

SVD MechanicsMarkus Friedl (HEPHY Vienna)

BPAC, 26 October 2015

IntroductionSliderWhat’s New?Summary

26 October 2015M.Friedl: SVD Mechanics 2

Overview


Layer

Radius [mm]

Ladders

Sensors /

Ladder

Slanted?

Windmill angle

[°]

Overlap [%]

6 135 16 5 9 9.0

5 104 12 4 5 3.8

4 80 10 3 6 15.4

3 38 7 2 x 6 7.1

Rect (122.8 x 38.4 mm , 160 / 50 um pitch)2

Rect (122.8 x 57.6 mm , 240 / 75 um pitch)2

W edge (122.8 x 57 .6-3 8.4 m m , 240 / 75..50 um pitch)2

0

0

10

3

45

6[cm] layers

[cm]

20

-10-20-30 10 20 30 40

6

z APVs

z APVs

z APVs

64

4

4 4

46

6

6

rphi APVs

rphi APVs

rphi APVs

6

64

4

4 4

4

4

46

6

66 6

6 6 6

6

Components

Not shown: Outer shell (CF)26 October 2015M.Friedl: SVD Mechanics 5

Ladders

End rings(SUS)

Carbon fiber(CF) cone

End flange(Aluminum)

Current Status: Rev. 2.4

Including all cooling pipes and connections to outside

Ladders are final – production has started Now working on service routing outside

of SVD volume


Exploded Ladder (Layer 5)


Origami flexes APV25 chips

Airex spacer

Silicon Sensors

PCB Hybrid

Pitch adaptersRibs

FWD End Mount

BWD End Mount

Mounting a Ladder

Ladders are positioned by two precision pins Fixed on backward side (origin) Sliding on forward side to allow thermal

movement


Simple Lock Mechanism (SLM)

SLM is used in layers 4,5,6 No screw driver access from

top Pin fits into precision hole in

end ring Locked by set screw Also provides cooling contact


BWD FWD

APV25 cover

End mountKokeshi pin

= origin of ladder

Swallow tail

Precision hole

Set screw hole

Accident With L5.001

2 issues came together: Sliding (FWD) mechanism was not correctly

adjusted (too much friction) Too little glue between ribs and sensors

Ladder was thermally cycled (100 cycles, -30…+60°C) Sensors detached from ribs


Same location after repair

Thermal Cycling After Repair (1/2)

A few cycles between 0...40°C Watched by camera (to confirm sliding action) Same setup as

already done onfirst class C ladderin January 2015

Motion due to CTE of aluminum support (ribs~0)


Thermal Cycling After Repair (2/2)

Video: https://youtu.be/QATnL9gPCdY

Sliding works well! Horizontal | vertical motion range: 370 µm | 180 µm

Comparable to L5.902 (class C) cycling in January: Horizontal | vertical motion range: 310 µm | 130 µm

Conclusion: repair of slider successful!


https://youtu.be/QATnL9gPCdY

What’s New Since November 2014?

Rev. 2.4 released Isolators and pipe routing finalized Ladder collision analysis Vibration test Cooling pipe bending Set screw tool Ladder mount tool next presentation Ladder transport container Packaging and shipping Ladder assembly status

talk


Cooling Pipes and Isolators


Collision Analysis

2 weaknesses revealed L6 rib to L5 FW clip: 0.16mm

Solution: make local dent in L6 ribs

Does not reduce stiffness Result: 1.2mm clearance

Adjacent CO2 clamps in L4: 0.63mm Slightly reduce clamp

thickness at end

26 October 2015 17M.Friedl: SVD Mechanics

L6 Rib Solution

Add local dent (similar to L5) Done in HEPHY machine shop

Does it weaken the structure?


Finite Element Analysis

Rev 2.4

Deformation: 1.793mm(under unrealistic pressure)

• Rev 2.4 + local dent

• Deformation: 1.794mm(same conditions)

Basically no difference


Vibration Test (1/2)

Performed at INFN Pisa on a class C (non-functional, but mechanically precise dummy) L5 ladder


Heavy support structure (resonance at 920 Hz)

Vibration Test (2/2)

0.2 g (left) and 0.6 g (bottom) sweeps from 20 to 1000 Hz show no resonances below 100 Hz


L6 Cooling Pipe Bending (1/3)

Part 1: flat meander – easier than anticipated


Stoppers

Tape for pipes fixation


Part 2: 3D shaping – did not work well


Linear guides

Moveable Parts

Origami pipe


Possible solutions: Option 1: use flat

pipe, as it is quite soft and easily follows 3D shape


Option 2: do 3D bending in one step

L6 Cooling Pipe Pressure Test @ MPI

We attached one end to the water high pressure system and closed the other side

Increased pressure gradually from 0 to 300 bar No movement of pipe could be seen

We waited 15 minutes and nothing happened Finally pressure was taken away

SUCCESS!26 October 2015 25M.Friedl: SVD Mechanics

Set Screw Tool


Torque screw driver

Flexible part

L5 Ladder Transport Container


2 base plates – inner one has slits for source test

Openings for source test(green lines show the way of the source test)

Source Test in Transport Container


@ HEPHY we use our test box with an X/Z stage

Source particles

Summary

SVD design Rev. 2.4 Including isolators and pipe routing

New since February 2014: Ladder collision analysis Vibration test Cooling pipe bending Set screw tool Ladder mount tool Ladder transport container Packaging and shipping


BACKUP


Packaging And Shipping

Different routes and approaches:

L3 ladders from Melbourne to KEK Accompanied transport by aircraft

L4 and L6 ladders from IPMU to KEK Transport by car

L5 ladders from Vienna to KEK Transport by shipping company (aircraft cargo) Recent test shipment with 2 class C ladders using

same packaging and procedure as intended for class A ladders


L5 Ladder Packaging


Ladder transport container,Sealed in dry air volume

svd mechanics markus friedl (hephy vienna) bpac, 26 october 2015

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