Title :
Effects of sextupole time dependence on the LHC dynamic aperture
Author :
Papaphilippou, Y. ; Schmidt, E. ; Zimmermann, E.
Author_Institution :
CERN, Geneva, Switzerland
Abstract :
A primary concern regarding the LHC dynamic aperture is the time dependence of persistent-current sextupole fields in the superconducting magnets. Decaying slowly during injection, these fields are reinduced rapidly at the start of the acceleration (“snap-back”). If uncompensated, this snap-back would cause a chromaticity change by some 130 units. We investigate how this time dependence and the ramp rate affect the stability of particle motion and we evaluate the efficiency of different correction schemes
Keywords :
accelerator magnets; colliding beam accelerators; particle beam dynamics; particle beam injection; particle beam stability; proton accelerators; superconducting magnets; synchrotrons; LHC dynamic aperture; chromaticity change; correction schemes; injection; particle motion stability; persistent-current sextupole fields; ramp rate; sextupole time dependence; superconducting magnets; time dependence; Acceleration; Apertures; Ear; Eddy currents; Large Hadron Collider; Magnetic fields; Particle tracking; Stability; Superconducting cables; Superconducting magnets;
Conference_Titel :
Particle Accelerator Conference, 1999. Proceedings of the 1999
Conference_Location :
New York, NY
Print_ISBN :
0-7803-5573-3
DOI :
10.1109/PAC.1999.794173
