Measurements of Tune Shifts with Amplitude at Lep
نویسندگان
چکیده
The beam orbit system of the LEP electron-positron collider is able to store the beam position over 1000 turns following a deflection by a horizontal kicker. A precise analysis of such 1000-turn data for many beam position monitors was used to study the dependence of the tune on the horizontal amplitude. The horizontal tune shift with amplitude was determined from the decay of the beam oscillation for various LEP optics. This parameter turned out to be an important issue for the LEP high energy optics.
منابع مشابه
Nonlinear Dynamics in Spear Wigglers
BL11, the most recently installed wiggler in the SPEAR storage ring at SSRL, produces a large nonlinear perturbation of the electron beam dynamics, which was not directly evident in the integrated magnetic field measurements. Measurements of tune shifts with betatron oscillation amplitude and with closed orbit shifts were used to characterise the nonlinear fields of the SPEAR insertion devices ...
متن کاملMeasurements of Impedance Distributions and Instability Thresholds in Lep
The distributionof reactive and resistive components of the transverse impedance around the circumference of LEP has been obtained by exciting the beam and measuring the variationsof phase advance and of closed orbit displacements with beam current. Tune shifts with current and instability thresholds were determined for two machine lattices with different beta functions and momentum compaction ...
متن کاملApplications of the 1000-turns Orbit Measurement System at LEP
The software of the LEP beam orbit measurement system [1] allows the acquisition of the beam position for over 1000 consecutive turns. The acquisition can be synchronized to a deflection by a kicker in order to observe coherent betatron oscillations. In this paper we describe the use of this technique to study the dependence of head-tail damping on beam parameters and the tune dependence on the...
متن کامل2003-2004 Nonlinear Optics Measurements and Modeling for the CERN SPS
In 2003 and 2004 nonlinear chromaticity, amplitude detuning, chromatic phase advance, resonance driving terms and off-energy orbits were measured in the CERN SPS at 14 GeV/c and 26 GeV/c, respectively. From the nonlinear chromaticity, the SPS optics model has been updated, by adjusting the strength of nonlinear field errors in dipoles and quadrupoles. Furthermore, we have added to the model the...
متن کاملMeasurements and Visualization of the Transverse Phase-space Topology at Lep
The LEP Beam Orbit Measurement system (BOM) allows for the acquisition of the beam position at each Beam Position Monitor (BPM) for over 1000 consecutive turns. By synchronizing the acquisition with a kick given to the beam, we can investigate the behavior of the beam under different conditions. In particular, starting from the data of one BPM, we can apply a simple mathematical manipulation to...
متن کامل