Ryan Badman Jim Crittenden July 20, 2011 Electron Cloud Meeting

Slides:

Advertisements

Similar presentations

45 th ICFA Beam Dynamic Workshop June 8–12, 2009, Cornell University, Ithaca New York Jim Crittenden Cornell Laboratory for Accelerator-Based Sciences.

Advertisements

RedOffice.com Presentation templates Slide No. 1 RFA Detector Data of Electron Cloud Build-up and Simulations Eric Wilkinson Mentor: Jim Crittenden Cornell.

Using Tune Shifts to Evaluate Electron Cloud Effects on Beam Dynamics at CesrTA Jennifer Chu Mentors: Dr. David Kreinick and Dr. Gerry Dugan 8/11/2011REU.

E-Cloud Effects in the Proposed CERN PS2 Synchrotron M. Venturini, M. Furman, and J-L Vay (LBNL) ECLOUD10 Workshshop, Oct Cornell University Work.

45 th ICFA Beam Dynamic Workshop June 8–12, 2009, Cornell University, Ithaca New York Jim Crittenden & John Sikora Cornell Laboratory for Accelerator-Based.

ECLOUD Calculations of Field Gradients During Bunch Passage Jim Crittenden Cornell Laboratory for Accelerator-Based Sciences and Education Electron Cloud.

Early Results on a Search for Cyclotron Resonances in ECLOUD -- Collaboration with Eric Wilkinson -- These slides includes corrections arising from the.

45 th ICFA Beam Dynamic Workshop June 8–12, 2009, Cornell University, Ithaca New York Resolution of ECLOUD Tune Shift Calculation Instability Jim Crittenden.

45 th ICFA Beam Dynamic Workshop June 8–12, 2009, Cornell University, Ithaca New York Modelling Cyclotron Resonances in ECLOUD 1) Comparison with CesrTA.

45 th ICFA Beam Dynamic Workshop June 8–12, 2009, Cornell University, Ithaca New York ECLOUD Simulations for the Tune Shift Measurements of December.

ECLOUD Calculations of Coherent Tune Shifts for the April 2007 Measurements - Study of SEY Model Effects - Jim Crittenden Cornell Laboratory for Accelerator-Based.

ECLOUD Calculations of Coherent Tune Shifts for the April 2007 Measurements - Study of SEY Model Effects - Jim Crittenden Cornell Laboratory for Accelerator-Based.

ECLOUD Calculations of Coherent Tune Shifts for the April 2007 and January 2009 Measurements - Preparation for PAC2009 FR5RF Paper and Poster - “Effects.

LEPP, the Cornell University Laboratory for Elementary-Particle Physics, has joined with CHESS to become the Cornell Laboratory for Accelerator-based Sciences.

Electron Cloud in ilcDR: Update T. Demma, INFN-LNF.

ECLOUD Calculations of Coherent Tune Shifts for the April 2007 Measurements - This presentation limited to resolving drift/dipole weighting question -

45 th ICFA Beam Dynamic Workshop June 8–12, 2009, Cornell University, Ithaca New York Jim Crittenden Cornell Laboratory for Accelerator-Based Sciences.

45 th ICFA Beam Dynamic Workshop June 8–12, 2009, Cornell University, Ithaca New York Recent Studies with ECLOUD Jim Crittenden Cornell Laboratory for.

Space Charge Electric-Field Calculations for Coherent Tune Shift Estimations using the Electron-cloud Modelling Algorithm ECLOUD Jim Crittenden Cornell.

ECLOUD Calculations of Coherent Tune Shifts for the April 2007 Measurements - Thanks to Marco for clarifying the drift/dipole weighting - - Thanks to Gerry.

Title Date Author for the C ESR TA Collaboration.

45 th ICFA Beam Dynamic Workshop June 8–12, 2009, Cornell University, Ithaca New York ECLOUD Simulations for the Tune Shift Measurements of December.

ECLOUD Simulations for CESR Witness Bunch Tune Shift Measurements Jim Crittenden Cornell Laboratory for Accelerator-Based Sciences and Education.

45 th ICFA Beam Dynamic Workshop June 8–12, 2009, Cornell University, Ithaca New York First Results on the Introduction of the Rediffused SEY Component.

45 th ICFA Beam Dynamic Workshop June 8–12, 2009, Cornell University, Ithaca New York Jim Crittenden Cornell Laboratory for Accelerator-Based Sciences.

49th ICFA Advanced Beam Dynamics Workshop October 8 –12, 2010 LEPP, the Cornell University Laboratory for Elementary-Particle Physics, has joined with.

45 th ICFA Beam Dynamic Workshop June 8–12, 2009, Cornell University, Ithaca New York Jim Crittenden Cornell Laboratory for Accelerator-Based Sciences.

45 th ICFA Beam Dynamic Workshop June 8–12, 2009, Cornell University, Ithaca New York ECLOUD News 1) Bug in SEY model fixed 2) List of present activities.

45 th ICFA Beam Dynamic Workshop June 8–12, 2009, Cornell University, Ithaca New York Jim Crittenden Cornell Laboratory for Accelerator-Based Sciences.

The Secondary Electron Yield Model in ECLOUD and Comparison to CLOUDLAND Jim Crittenden Cornell Laboratory for Accelerator-Based Sciences and Education.

March 23, 2010 CMAD a tracking and e-cloud beam instability parallel code (M.Pivi SLAC) Taking MAD(X) optics file at input, thus tracking the beam in a.

November 18, 2011David L. Rubin1 CESR Test Accelerator – Investigation of the physics of charged particle beams Circumference = 768m - Beam energy

Shielded-Pickup Measurements in June and Update on Modeling Results / J.A. Crittenden 23 August / 4 Shielded-Pickup Measurements in June and Update.

FCC-hh: First simulations of electron cloud build-up L. Mether, G. Iadarola, G. Rumolo FCC Design meeting.

2nd International Particle Accelerator Conference September 4–9, 2011, San Sebastián, Spain LEPP, the Cornell University Laboratory for Elementary-Particle.

Electron Cloud Studies at DAFNE Theo Demma INFN-LNF Frascati.

45 th ICFA Beam Dynamic Workshop June 8–12, 2009, Cornell University, Ithaca New York Jim Crittenden Cornell Laboratory for Accelerator-Based Sciences.

45 th ICFA Beam Dynamic Workshop June 8–12, 2009, Cornell University, Ithaca New York Jim Crittenden Cornell Laboratory for Accelerator-Based Sciences.

45 th ICFA Beam Dynamic Workshop June 8–12, 2009, Cornell University, Ithaca New York Jim Crittenden & John Sikora Cornell Laboratory for Accelerator-Based.

45 th ICFA Beam Dynamic Workshop June 8–12, 2009, Cornell University, Ithaca New York Jim Crittenden Cornell Laboratory for Accelerator-Based Sciences.

45 th ICFA Beam Dynamic Workshop June 8–12, 2009, Cornell University, Ithaca New York Jim Crittenden Cornell Laboratory for Accelerator-Based Sciences.

LEPP, the Cornell University Laboratory for Elementary-Particle Physics, has joined with CHESS to become the Cornell Laboratory for Accelerator-based Sciences.

45 th ICFA Beam Dynamic Workshop June 8–12, 2009, Cornell University, Ithaca New York Jared Ginsberg Cornell Laboratory for Accelerator-Based Sciences.

Status of ECLOUD Simulations for the Shielded Button Measurements

Electron Cloud Measurement Summary for the April 2014 Run

Using Time-Resolved Retarding Field Analyzer Measurements to Determine the SEY Mitigation Effectiveness of Grooves -- Bonus: first look at last night's.

RECENT DEVELOPMENTS IN MODELING

Electron Cloud Meeting

Physics Scope and Work Plan for the Shielded-Pickup Measurements -- Synchrotron Radiation Photon Distributions Photoelectron Production Parameters.

First Look at the New SYNRAD3D Results

Detailed Characterization of Vacuum Chamber Surface Properties Using Measurements of the Time Dependence of Electron Cloud Development Jim Crittenden.

RECENT DEVELOPMENTS IN MODELING

Use of the Shielded-Pickup Measurements for Optimization of the Photoelectron Production Energy Distribution in ECLOUD -- This topic was included in the.

Physics Scope and Work Plan for the Shielded-Pickup Measurements -- Synchrotron Radiation Photon Distributions Photoelectron Production Parameters.

First Look at Modeling Photoelectron Energy Distribution for a 2

Shielded Button Measurement/ECLOUD Simulation Comparison for 5

Electron Cloud Meeting

Ecloud in quadrupole & Sextupole

Jim Crittenden Electron Cloud Meeting 4 December 2013

First Attempt to Simulate the Shielded Button Measurements with ECLOUD

J.A.Crittenden, Y.Li, X.Liu, M.A.Palmer, J.P.Sikora (Cornell)

Quadrupole Shielded-Pickup Data Comparison of Signals from 10- and 20-Bunch e+ Trains -- Trapping ! Updated after meeting to include suggested.

All material for this talk may be obtained at

Electron Cloud in ilcDR: Update

SuperB General Meeting June , Perugia (Italy)

Code Benchmarking and Preliminary RFA Modelling for CesrTA

Status of Ecloud Build-Up Simulations for the ILC DR’s

LCLS Commissioning Parameters

Electron Cloud Build-up in ilcDR

CesrTA Wiggler RFA Measurements

Presentation transcript:

Ryan Badman Jim Crittenden July 20, 2011 Electron Cloud Meeting Progress in ECLOUD Simulations for the 5.3 GeV e+ Witness Bunch Measurements with the Shielded Pickups Ryan Badman Jim Crittenden July 20, 2011 Electron Cloud Meeting

Improvements and End Result -As mentioned by Jim Crittenden at the 7/13 meeting, the witness bunch simulations have been improved by independently adjusting quantum efficiencies and photoelectron energy distributions for direct and reflected photons, and tuning other input parameters such as the secondary energy distribution. -The secondary energy distribution will be the focus of this talk, both the functional form and the input parameter SEMAX. Present status of optimization

Intro to Changes in Secondary Energy Distribution ECLOUD simulations up to now have used the distributions introduced by Noel Hilleret based on Phil.J.Res. 50 (1996), 375: f(Esec) ~ exp( -ln(Esec/SEMAX)2/2 ), with SEMAX=1.8 eV Use of a distribution attributed to Miguel Furman improved the comparison to data: f(Esec) ~ Esec exp (-Esec/SEMAX ), with SEMAX=0.8 eV As the next two slides will show, Noel's distribution has too many high energy e-, giving a broad late signal after the leading bunch which is not seen in the measurements. Original Optimized Optimized

f(Esec) ~ exp( -ln(Esec/SEMAX)2/2 ) f(Esec) ~ Esec exp (-Esec/SEMAX ) Original vs. Optimized f(Esec) ~ exp( -ln(Esec/SEMAX)2/2 ) SEMAX=1.8 eV f(Esec) ~ Esec exp (-Esec/SEMAX ) SEMAX=0.8 eV

Why Miguel's Distribution is Used When the same optimal value of 0.8 eV is used for both, the exponential functional form eliminates the nonphysical late broad peak observed with the original ECLOUD parabolic log function. Parabolic log (Noel) Exponential (Miguel) eV

Sensitivity to SEMAX Parameter (Miguel's function) (Note the late simulation peak at SEMAX>0.8 eV that is not present in the data)

Where does late peak come from? Photoelectrons from the top of the beam pipe and from direct photons produce secondaries that cause this signal.

Lower bound on SEMAX obtained from 14-ns witness bunch signal shape

Summary 1) 5.3 GeV simulations have made great progress in describing the SPU witness bunch data. 2) The best SEMAX value is around 0.8 eV. Above 1.0 eV an unphysical, late, broad peak appears in the simulation. Below 0.8 eV, the 14-ns witness bunch signal shape simulation is poor. 3) The sensitivity to SEMAX appears to be about 0.2 eV. 4) Miguel's exponential distribution gives a better match than the Phil.J.Res. parabolic log function. 5) Future work: Will the 2.1 GeV analysis corroborate this result for the 5.3 GeV data?