Title :
Geometric and magnetic axes of the LHC dipole
Author :
Bajko, M. ; Billan, J. ; Buzio, M. ; Deferne, G. ; Ferracin, P. ; Garcia-Perez, J. ; Scandale, W. ; Todesco, E.
Author_Institution :
CERN, Geneva, Switzerland
Abstract :
The 15-m long superconducting dipoles of the Large Hadron Collider (LHC) with two-in-one design are curved by about 5 mrad to follow the beam trajectory. They are supported on three cold feet to minimise the vertical sagitta induced by their 35 tonnes weight. The cold masses contain at both ends local multipolar correctors to compensate for the detrimental effect of persistent current during injection. We discuss how we measure and control the geometrical shape of the cold mass and the alignment of the associated correctors and how we identify the magnetic axis of the field-shape harmonics with respect to the expected beam reference orbit. We present results relative to prototype dipoles obtained both at room temperature and in operational conditions at 1.9 K
Keywords :
accelerator magnets; colliding beam accelerators; proton accelerators; storage rings; superconducting magnets; 1.9 K; LHC; Large Hadron Collider; beam reference orbit; cold mass; field-shape harmonics; local multipolar correctors; persistent current; superconducting dipoles; Colliding beam devices; Extraterrestrial measurements; Large Hadron Collider; Magnetic field measurement; Persistent currents; Prototypes; Shape control; Shape measurement; Superconducting magnets; Weight control;
Conference_Titel :
Particle Accelerator Conference, 2001. PAC 2001. Proceedings of the 2001
Conference_Location :
Chicago, IL
Print_ISBN :
0-7803-7191-7
DOI :
10.1109/PAC.2001.988121
