Technical Review on Beam Line Alignment at KEKB Facility
Detailed overview of the alignment strategies, measurements, and completion status of girder alignment using laser straight techniques at KEKB facility. The process involves laser trackers, micrometer measurements, and monitoring floor movement to ensure precise alignment for optimal equipment performance.
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Presentation Transcript
Beam line alignment status 2014. March. 4 Takuya Kamitani
initial alignment strategy laser straight of girders in sector-A, B component alignment by laser tracker laser straight of girders in sector-C to 5 component alignment by laser tracker J-arc alignment by laser tracker 2
at KEKB Review 2013 girder straightness before laser straight alignment A,B-sector 1.0mm 0.0mm 3
aligned in laser straight but time variation A,B-sector 0.1mm Junction /V Ver. ~0.65 200 microns - 0.1mm position variation in (9/10 120 m 9/16, 2013) #2=A1D #2=PD-R001D Sensor position The movement over a week amounted to 200 microns or more. 2013/11/11 T. Higo SuperKEKB WS 4
Micrometer measurement setup between an expansion joint Base plate on the wall Junction Wall Vertical Arm Horizontal Arm Micrometer Floor
Relative floor movement between both sides of expansion joint 1 day Summary at 3 junctions Typical example of vertical movement: between C3 and C4 @C3, @12, @18 Item Hor. daily Hor. drift Ver. daily Ver. drift 2 10 [ m] Vertical [mm] Electricity cut 1 week 50 m 2 5 [ m/day] 15 30 [ m] [day] 1 5 [ m/day] Daily 20 m(full), Drift 3.5 m/day Junction: The daily movement amounts to 20-30 microns, while weekly to several tens of microns. 6
girder alignment completed ( <0.3mm) in laser straight in sector-A, B only pre-alignment in laser straight in sector-C to 2 (still in construction stage) to be aligned in April 2014 & detail alignment in 2014 summer shutdown only pre-alignment by laser tracker in sector-3 to 5 (in operation for PF & PFAR) detail alignment in laser straight in 2014 summer shutdown 7
at KEKB Review 2013 short-distance (local) alignment Hard ware alignment on a 10m girder B2-V B2-H 0.228 0.266 0.136 B4-H B4-V Reference bars (blue) are set typically within 0.1mm. Ver < 0.2mm Hor. up to 0.5mm slope Systematic error may exists in H by 0.5mm, while V stays 0.2mm from reference bar. 8 K. Kakihara, 22 Nov. 2012
Accelerator structure alignment on a girder, measured w.r.t. PD arms Examples showing the present status: Statistics of three units (C1, C2, C3) Horizontal Average = 2 microns Stand. Dev. = 16 microns Easy adjustment by shimming Vertical Average = 5 microns Stand. Dev. = 51 microns A little tedious but can be adjusted by screw bolts 9
component alignment completed ( <0.1mm) for acc. structures in sector-A, B for magnets, add-on reflector base for laser tracker to be installed, to be aligned in 2014 summer shutdown completed ( <0.1mm) for acc. structures in sector-C, 1 before target for magnets, add-on reflector base for laser tracker to be installed, to be aligned in 2014 summer shutdown only rough alignment in 1-3 to 2-6 (still in construction) to be aligned in 2014 summer shutdown only pre-alignment by laser tracker in sector-3 to 5 (in operation for PF & PFAR) detail alignment in 2014 summer shutdown 10
J-arc reference lines were re-defined from 180 degree wrt A-B line to symmetric wrt A-B, C-5 lines from geoid surface to the linac common plane B - A 90 ? ? ? ???? 15000 mm + d mm C - 1 90 ? Arc B - A C - 1 ? Vertical Horizontal Inclination set along A-B Close to C-5 line ~ 0.049 mrad Both lines /2 from parallel lines = 0.114 mrad data from M. Tanaka 11
j-arc components position adjustment horizontal vertical [1 mm] 2013/11/11 12
J-arc alignment once completed ( <0.05mm), however systematic error by laser tracker found in horizontal plane, (seems to be OK for vertical) after the magnet position adjustment the error in position can amount to 1mm need re-adjustment, to be performed in 2014 summer shutdown 13
