marcel vreeswijk (nikhef) agenda xray tomograph -bol0 results (martin) bol0 and bol2 features...

Marcel Vreeswijk (NIKHEF)

AGENDAAGENDA• Xray tomograph -BOL0 results (Martin)• BOL0 and BOL2 Features (Graziano)• Discussion (All)

Features and Mysteries of BOL chambers

Features and Mysteries of BOL chambers

Marcel Vreeswijk (NIKHEF) s

BOL0 - Hypothesis

OBSERVATIONS BOL0OBSERVATIONS BOL0•Y-pitch between inner wire-layers: 20um too large•Y-Pitch between outer wire-layers: only slightly too large

•Y-Pitch between multilayers: 75um too small

HypothesisHypothesis•Glue shrimp between tubes and spacer? (2x500um glue gap)--> measured: <5um effect for 1mm gap

•Xplate deforms during gluing. In particular the flange--> presented today

Additionally:Additionally:•Re-analysis of BOL0 construction RASNIK readings: ‘cumulative effects’ lead to better agreement!


Floppy Xplate wrt tubes

s

@longbeam

Away from longbeam

=Rotation of unknown relative size

Tube direction bends flanges

Longbeam constraints body Xplate locally

‘Tube-length’ bends body


Sag Adjustment

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‘Tube-length’ constraints flanges

Tube direction bends flanges


Away from longbeam flange bends differently!

BOL0 is scanned with sag-adjustment (partially) on!BOL0 is scanned with sag-adjustment (partially) on! (Longbeam sag is assymetric in BOL0)(Longbeam sag is assymetric in BOL0)

When we are optimistic: deformation is symmetric for up/down ML.


Sag Compensation

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‘Tube-length’ constraints flanges

Tube direction bends flanges (temporary)



XP deformation

For now, BOL2 is still equipped with gauges, located on the inner side of the HV-xplate

During BOL2 construction, the flange of the HV xplate was measured with micro-gauges:LBF: Longbeam- FlangeBF: Body- Flange


Gluing BOL-0• Stability Xplates during gluing

Start glue

Start glue

Layer 2

Layer 3

Yrasnik=2 x Sag

Start glue

Layer 1

Layer 1: dSag=7um

Layer 2: dSag=10um

•The sag of the xplates in layer 1 and 2 change in time. •Layer 3,4,5,6: Sag stable

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Sag Compensation

End: -38/2 um

Start: -15/2 um

Start: 30/2 umEnd: 50/2 um

During gluing of layer 1 and 2, significant changes in xplate sag were observed:•In-stable reduction valves?•Effect of glue viscosity?

Layer 1

Layer 2

1 deg

BOL2BOL2


Conclusions

OBSERVATIONS BOL0OBSERVATIONS BOL0Y-pitch between inner wire-layers: 20um to largeY-Pitch between outer wire-layers: only slightly to large:•Effects largely explained by RASNIK measurements during construction. • Flange deformation of order 10um could be ‘baked’ in.

Y-Pitch between multilayers: 75um to small:•Flange deformations of this order are certainly observed. However these deformations appear symmetric and elastic.•Needs more study -> effects of kinematic mounts•direct -in situ- measurement dY of Frascati comb and towers


Test @CERN inTomograph (BOL0)

Wire positionsRMS 16m

Analysis of Martin Woudstra


Parallelogram-ness

Checks distance wrtComb @ RO side

For stability bare spacer

“BOL

rail

RO


Landing-Tool•Problems with lowering gluing tube layers on tube layers due to glue viscosity

•Landing tool pre-aligns chamber and ensures flat landing in glue.

BOL

Tower

Effective + EasyEffective + Easy


Cosmic Ray Stand

marcel vreeswijk (nikhef) agenda xray tomograph -bol0 results (martin) bol0 and bol2 features...

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