Collimators

Transverse Resistive Wall Impedance with Finite Length, New GSI RW-Impedance Result for the LHC Collimator, Comparison of CERN and GSI RW Impedance Results for SIS100  (E. Metral, RLC 12.09.2006)

list of primary collimators and secondary collimators, beta functions, half gaps at injection (excel file)

list of primary collimators and secondary collimators, beta functions, half gaps at top energy (excel file)

bench measurements by Fritz Caspers and Tom Kroyer (pdf file) 

Benchmarking of resistive impedance, comparison of different theories (E. Metral, RLC 07.07.2006)

Updated GSI Impedance Results

Latest Estimates of Collimator Impedance Effects (EM, CWG 17.07.2006)

Simulation of trapped modes in LHC collimator (Alexej Grudiev, RLC 28.01.2005)

Tune Shift due to the Trapped Modes of the SPS (Horizontal) Prototype of the LHC Collimator (Elias Metral, RLC 05.02.2005)

Trapped Modes for SPS and LHC Collimator (Elias Metral, RLC 11.02.2005)

Transverse Impedance of Trapped Modes in LHC Collimator (Alexej Grudiev, RLC 11.02.2005)

Resistive-Wall Impedance with Inductive Bypass for the LHC Collimators (Elias Metral, RLC 06.02.2004)

Transverse Resistive-Wall Impedance: Comparison Zotter - Burov/Lebedev - Classical Thick-Wall (Elias Metral, RLC 28.01.2005)

Transverse Resistive-Wall Impedance for SIS100 and LHC Collimator (Elias Metral & Slava Zhabitsky, RLC 17.03.2006)

Comparing Theoretical Predictions and Measurements for 2004 SPS LHC-Collimator Test (Frank Zimmermann, RLC 20.01.2006)

Simulation of Longitudinal and Transverse Impedances of Trapped Modes in LHC Secondary Collimator, A. Grudiev, AB-Note-2005-042

Tensor Transformation for Impedance of Tilted Collimators (Francesco Ruggiero, RLC 03.10.2003)

33. LTC (27-Oct-2004): Scaling the SPS collimator RF trapped modes measurements to 7 TeV; Bernd Dehning comments on the measurement of the trapped RF modes that the results must be scaled to 7 TeV before one can conclude that these modes are not dangerous.  Ralph Assmann agrees that this still need to be done. (email Oliver Bruning to Francesco Ruggiero, March 2006). There have been a lot of analysis and follow-up of the LHC collimator test. Trapped modes have been simulated and compared to measurements (see in particular ABP-RLC meetings of 28-Jan-2005, 4-Feb-2005, and 11-Feb-2005): heat loads induced by the LHC beam and RF finger heating have been computed and the collimation team has been informed. The effect on the LHC beam at 7 TeV has been estimated: slow multi-bunch instability rise times between 20and 100 sec are expected, which can be damped by Landau octupoles or by the feedback system. (email Francesco Ruggiero to Oliver Bruning, 14.03.2006)