CERN Accelerating science

Article
Title	Measurements of Field Decay and Snapback Effect on Tevatron Dipole and Quadrupole Magnets
Author(s)	Velev, Gueorgui ; Ambrosio, Giorgio ; Annala, Gerald ; Bauer, Pierre ; Carcagno, Ruben H ; Di Marco, Joseph ; Glass, Henry ; Hanft, Ray ; Kephart, Robert ; Lamm, Michael J ; Martens, Michael A ; Schlabach, Philip ; Sylvester, C D ; Tartaglia, M ; Tompkins, John
Affiliation	(Fermilab, Batavia, Illinois)
Publication	2005
In:	21st IEEE Particle Accelerator Conference, Knoxville, TN, USA, 16 - 20 May 2005, pp.2098
Subject category	Accelerators and Storage Rings
Abstract	Since the beginning of 2002 an intensive measurement program has been performed at the Fermilab Magnet Test Facility to understand dynamic effects in the Tevatron magnets. Based on the results of this program a new correction algorithm was proposed to compensate for the decay of the sextupole field during the dwell at injection and for the subsequent field "snapback" during the first few seconds of the energy ramp. Beam studies showed that the new correction algorithm works better than the original one, and improves the Tevatron efficiency by at least 3%. The beam studies also indicated insufficient correction during the first 20 s of the injection plateau where an unexpected discrepancy of 0.15 sextupole units of extra drift was observed. This paper reports on the most recent measurements of the Tevatron dipoles field at the beginning of the injection plateau. Results on the field decay and snapback in the Tevatron quadrupoles are also presented.