1. Marcel Vreeswijk (NIKHEF) AGENDA Xray tomograph -BOL0 results (Martin) BOL0 and BOL2 Features (Graziano) Discussion (All) Features and Mysteries of BOL chambers

2. Marcel Vreeswijk (NIKHEF) s BOL0 - Hypothesis OBSERVATIONS 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 Hypothesis Glue shrimp between tubes and spacer? (2x500um glue gap) --> measured: <5um effect for 1mm gap Xplate deforms during gluing. In particular the flange --> presented todayAdditionally: Re-analysis of BOL0 construction RASNIK readings: ‘cumulative effects’ lead to better agreement!

3. Marcel Vreeswijk (NIKHEF) 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

4. Marcel Vreeswijk (NIKHEF) Sag Adjustment s =Rotation of unknown relative size ‘Tube-length’ constraints flanges Tube direction bends flanges Longbeam constraints body Xplate locally Away from longbeam flange bends differently! 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.

5. Marcel Vreeswijk (NIKHEF) Sag Compensation s =Rotation of unknown relative size ‘Tube-length’ constraints flanges Tube direction bends flanges (temporary) Longbeam constraints body Xplate locally

6. Marcel Vreeswijk (NIKHEF) s 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- Flange BF: Body- Flange

7. Marcel Vreeswijk (NIKHEF) Gluing BOL-0 Stability Xplates during gluing 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 s

8. Marcel Vreeswijk (NIKHEF) s Sag Compensation End: -38/2 um Start: -15/2 um Start: 30/2 um End: 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 BOL2

9. Marcel Vreeswijk (NIKHEF) s Conclusions OBSERVATIONS BOL0 Y-pitch between inner wire-layers: 20um to large Y-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

10. Marcel Vreeswijk (NIKHEF) s Test @CERN in Tomograph (BOL0) Wire positions RMS 16  m Analysis of Martin Woudstra

11. Marcel Vreeswijk (NIKHEF) s Parallelogram-ness Checks distance wrt Comb @ RO side For stability bare spacer “BOL rail RO

12. Marcel Vreeswijk (NIKHEF) s 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 + Easy

13. Marcel Vreeswijk (NIKHEF) s Cosmic Ray Stand