Field quality of two 1-m model magnets for LHC low-βquadrupole magnets

摘要

Two 1-m model magnets for the LHC low-β quadrupoles were constructed and tested in KEK. They were energized to over 240 T/m. The field quality was measured by two harmonic coils. The multipole components were estimated along the straight section and the magnet ends. The results obtained show that the effect of the thermal cycle on the magnetic field is negligible. The time dependence of the multipole components were also measured at 420 A and it was found that b6 changed 0.8 units over 3 hours. This paper describes the magnetic field quality of the two magnets