S Myers

The Large Hadron Collider (LHC) in the LEP tunnel

After the remarkable start-up of LEP, the installation of a Large Hadron Collider, LHC, in the LEP tunnel will open a new era for the High Energy Physics. This report summarizes the main LHC parameters and subsytems and describes the more recent studies and developments.

Accelerator physics at LEP

Accelerator physics issues and their influence on performance are presented for the Large Electron-Positron (LEP) storage ring at CERN in Geneva, Switzerland. After several years of operation on the Z boson resonance at beam energies around 45 GeV, the beam energy was increased in steps to over 100 GeV. The major power loss to synchrotron radiation and its consequences on the maximum beam energy are discussed. The subjects of luminosity optimization, beam-beam effect, instabilities, detector backgrounds and beam lifetime are addressed. The precise beam energy calibration, which is of particular importance for the determination of standard model parameters, is described.

The Energy calibration of LEP in the 1993 scan

This report summarizes the procedure for providing the absolute energy calibration of the LEP beams during the energy scan in 1993. The average beam energy around the LEP ring was measured in 25 calibrations with the resonant depolarization technique. The time variation of this average beam energy is well described by a model of the accelerator based on monitored quantities. The absolute calibration of the centre of mass energies of the off-peak points is determined with a precision of 2 parts in 105 resulting in a systematic error on the Z-mass of about 1.4 MeV and on the Z-width of about 1.5 MeV.

Francesco Ruggiero 1957-2007

Francesco Ruggiero (1957-2007) was a brilliant acceler- ator physicist, an inventive researcher, a great collaborator, an excellent mentor, and a true gentleman. We here take a look at Francescos scientific work, and highlight some of his contributions to accelerator physics. More details can be found in the slides presented by the speakers of the Francesco Ruggiero Memorial Symposium held at CERN on 3 October 2007 (2).