CERN Accelerating science

Article
Report number	CERN-SL-96-036
Title	A newly observed Effect affects the LEP Beam Energy
Author(s)	Brun, G ; Dehning, Bernd (CERN) ; Galbraith, Peter ; Henrichsen, K N ; Koratzinos, M ; Placidi, Massimo ; Puzo, P ; Drees, A ; Geitz, M A
Affiliation	(BUGH, Wuppertal, Germany) ; (RWTH, Aachen, Germany) ; (CERN)
Publication	1996
Imprint	1996
Series	(Report)
In:	5th European Particle Accelerator Conference, Sitges, Barcelona, Spain, 10 - 14 Jun 1996, pp.421-423
Subject category	Accelerators and Storage Rings
Accelerator/Facility, Experiment	CERN LEP
Abstract	The LEP magnetic bending field and therefore the beam energy is changed by a current flow over the vacuum chamber. The current is created by trains travelling between the Geneva main station and destinations in France. Some of the rail current leaks into earth and returns to the power station via the LEP tunnel, where the vacuum chamber is one of the conductors. Train leakage currents penetrate LEP at the injection lines from the SPS close to IP1 and between IP5 and IP7, thereby interacting with the magnetic dipole field. The observed changes in B field cause beam energy increases of several MeV.

Corresponding record in: Inspire