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The geometrical tolerances of the SSS At the cold mass construction ( ACCEL) and after cold test of the cryo magnets (CERN WP18) M. Bajko AT MAS 28th of March. 2006. Summary: ECR on the length Angular defect of V line flanges. Tolerance table.
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The geometrical tolerances of the SSS At the cold mass construction ( ACCEL) and after cold test of the cryo magnets (CERN WP18) M. Bajko AT MAS 28th of March. 2006 Summary: ECR on the length Angular defect of V line flanges
Tolerance table All tolerances at ACCEL are given in the 12 plug co-ordinate system, while at WP18 at CERN is given in the GA co-ordinate system 1461.25 4124.25 5585.5 1. The Radial tolerance of V1&V2 on the Connection at WP18 are relaxed values as offered by VAC, thank to experiment gained with BPM/beam-screen/drift tube installation. A ‘grey area’ (up to 0.8mm) can be accepted with some caution, see minutes WGA72. 2. If the tolerance is exceeded, the angle w.r.t. the local axes of the cold bore tube shall be measured and checked with the same tolerance. 8 8 Nominal length to be changed with +2 mm. ECR by MM 1.5 Aperture tolerances at WP18 : race-track area, see figure below Connection side : g = 0.5 mm, r = 0.6 mm Lyra side : g = 0.5 mm, r = 0.65 mm A) In case of non-conformity for aperture, a shift or rotation is applied to the whole assembly at installation in order to close it.
V lines Downstream side ACCEL= 0.6 mm ( 8 mrad) CERN= 0.6 mm ( 8 mrad) LACCEL= ±0.5 mm LCERN= ±0.5 mm RACCEL= 0.6 mm RCERN= 0.87 mm ACCELmax=CERNmax = 73.25 mm ACCELmin=73.45 mm CERNmin = 73.4999 mm
ACTIONS IN AT-MAS and ACCEL • There is one repair finished on SSS133: procedure as in dipoles: see doc. Edms 677407 • Good co-orrelation is found between ACCEL and CERN . On 154 cold masses: correlation co-efficent is 0.93. therefore the defect can be identified before the cold mass is cryostated and plane the necessary repairs. The list of cold masses to be repaired is done and given to SSS co-ordination. • After OCT. 2005 no Nc were detected on magnet coming from from ACCEL . It was requested to do, if necessary ,repairs in Accel (1 case was reported of such repair by. K. Schirm).