Why field Quality is important?
Sources of Field Errors
Impact of Cable Thickness on Field Quality
Results from Present Day Magnets (Real Magnets) What has a major impact on random field errors? Is it cable thickness or some thing else?
Conventional Wisdom: Increasing Aperture Reduces Standard Deviation at 2/3 of the Coil Radius.
Influence of magnet components on field errors (From: R. Gupta, LHC Collective Effects Workshop, Montreux, 1995. Published in Particle Accelerators)
Field Quality in SSC Magnets (Lab built prototype dipoles)
Field Errors in SSC dipoles How off we were from reality?
Why were we so wrong in estimating field errors in SSC dipoles?
Measured Current Dependence in Sextupole in SSC Magnets
Influence of Lorentz Forces
Feedback in design from HERA experience: The Real Magnet Vs. Paper Design
Feedback in design from HERA experience A Method to Adjust Integral Field and Skew Quad
Three magnets with similar apertures Tevatron, HERA and RHIC
Comparison of Field Quality in three similar aperture magnets
Comparison of Field Quality in Tevatron, HERA and RHIC dipoles
Relaxation of Tolerances
Errors in Modern Measurement System
Different Size Cable (within spec) from Two Different Vendors
Flexible Design (Adjustment in b5 During Production in Q1)
Saturation in RHIC Arc Dipoles
Saturation Control in RHIC Dipoles Variation in |B| in Iron Yoke
Average Field Errors on X-axis
Lessons Learnt from the RHIC Dipole Production
RHIC 100 mm Aperture Insertion Dipole: The first magnet gets the body harmonics right
Average Field errors ~10-4 up to 80% of the coil radius
Tuning Shims for 10-5 Field Quality at 2/3 of coil radius
Field Quality Improvements with Tuning Shims (Skew Harmonics)
Ultimate Field Quality in SC Magnets
Field Quality in Common Coil Design
Common Coil Design
Field Quality Optimization in Common Coil Design (Magnet Body- Geometric)
Field Quality Optimization in Common Coil Design (Magnet Body- Yoke Saturation)
Field Quality Optimization in the Common Coil Design (Magnet Ends)
Persistent Current-induced Harmonics (may be a problem in Nb3Sn magnets, if nothing is done)
Persistent Current-induced Harmonics Traditional solution: work on the superconductor
PPT Slide
Summary and Conclusions
Email: gupta@bnl.gov
Home Page: http://www.bnl.gov/magnets/Staff/Gupta/
Other information: Presented at the Annual VLHC Meeting at Monterey, CA, June 28-30, 1999.
View or Download PDF version (1.6 MB)