All material for this talk may be obtained at

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.

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.

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

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 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.

Comparison of Primary Photoelectron Generation in ECLOUD, CLOUDLAND and POSINST Jim Crittenden Cornell Laboratory for Accelerator-Based Sciences and Education.

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.

45 th ICFA Beam Dynamic Workshop June 8–12, 2009, Cornell University, Ithaca New York Modeling Cyclotron Resonances in ECLOUD Jim Crittenden Cornell Laboratory.

45 th ICFA Beam Dynamic Workshop June 8–12, 2009, Cornell University, Ithaca New York Comparison of ECLOUD Calculations in Dipole and Quadrupole Fields.

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.

ElectronsdFud Simulation Work at Cornell Jim Crittenden Cornell Laboratory for Accelerator-Based Sciences and Education.

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.

45 th ICFA Beam Dynamic Workshop June 8–12, 2009, Cornell University, Ithaca New York Comparison of ECLOUD Calculations in Dipole and Quadrupole Fields.

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.

45 th ICFA Beam Dynamic Workshop June 8–12, 2009, Cornell University, Ithaca New York CesrTA Electron Cloud Measurements and Simulations Jim Crittenden.

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 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.

Electron Cloud Mitigation Studies at CesrTA Joseph Calvey 10/1/2009.

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.

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

RFA Simulations Joe Calvey LEPP, Cornell University 6/25/09.

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.

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 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

Update to ECLOUD Calculations for the

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

Jim Crittenden Electron Cloud Meeting 4 December 2013

Ryan Badman Jim Crittenden July 20, 2011 Electron Cloud Meeting

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.

SuperB General Meeting June , Perugia (Italy)

Code Benchmarking and Preliminary RFA Modelling for CesrTA

A Mapping Approach to the Electron Cloud for LHC

45 e+ bunches, 4-ns spacing, 0.9 mA/bunch

Recent Advances in Electron Cloud Buildup Measurements and Models at CESR (Part 2) Stephen Poprocki & Jim Crittenden Cornell University Accelerator Physics.

Presentation transcript:

Recent Progress in the ECLOUD Simulation for the Cloud Lifetime Study Using Witness Bunch Data All material for this talk may be obtained at www.lepp.cornell.edu/~critten/cesrta/ecloud/3nov10 See also previous talks on simulations for the shielded button data on 4/21, 4/28, 5/12, 7/7, 7/14, 8/4, 9/8, 9/22/2010 A primary purpose of the shielded pickup project (time-resolved measurements) is to measure the cloud lifetime. This lifetime is sensitive to the secondary yield for low-energy cloud particles hitting the vacuum chamber wall. First results on the sensitivity to the parameter d0 using witness bunch data was shown on 9/22/2010 and at ECLOUD10. Those results showed problems with the rising edge of the primary signal and normalization discrepancies at the level of a factor of 4. These have been resolved recently. Also, the modeling of secondaries generated in the SPU port holes has been added to ECLOUD. Jim Crittenden Cornell Laboratory for Accelerator-Based Sciences and Education Electron Cloud Meeting 3 November 2010

ECLOUD simulation for the cloud lifetime study using 5 mA/bunch e+ data at 15E (TiN) Secondary Yield Model True secondary yield: 0.9 True secondary peak energy: 400 eV Rediffused yield: 0.1 Elastic yield d0: 0.55 Two 5-mA bunch spaced by 14, 28, 42, 56, 70, 84 ns. ECLOUD statistical errors are shown. The measured button signals are shown as smooth dotted lines. The measured signals are scaled by an arbitrary factor of 7. Simulated cloud lifetime too long: reduce elastic yield?

ECLOUD cloud lifetime sensitivity to elastic yield d0 -- Status as of ECLOUD10 -- The optimal value for d0 (0.15) is lower than has been generally assumed (0.5-0.7). Note that not only the simulated peak signal value for witness bunch signals is better, but also the width. Could such a low elastic yield be a characteristic of TiN coating? Our tune shift simulations gave reasonable cloud decay times with a value of 0.5 for uncoated aluminum chambers.

New photoelectron energy distribution Green: ECLOUD original Red: ECLOUD10 Blue: better match to data

New SPU Acceptance Model I) Transparency for perpendicular incidence: Aq = 0 = 0.298 II) Angle acceptance: Aq= (1 – q / qmax) 2 III)Position Acceptance: Ax = sqrt(1-x2/r2) IV) Energy acceptance: E > 0.01 eV After the photoelectron energy distribution was corrected a very low energy tail of signal macroparticles inconsistent with the measured signal appeared. John pointed out that these will not traverse the holes if 1 Gauss stray field is present. q qmax

Secondaries generated in the SPU port holes Red: All signal macroparticles Blue: Hole secondaries 1) Direct signal: Qmp Aq=0 Aq Ax 2) Signal from secondaries: Qmp Aq=0 AxAq 2 The acceptance in the secondary angle Aq 2 depends on the average depth and hence on the incident angle q. 3) Normal secondaries generated with Qmp ( 1 - Aq=0 Ax) 4) Ignore hole secondaries which hit the hole wall 5) Ignore secondaries which re-enter the beampipe Time (ns)

ECLOUD cloud lifetime sensitivity to elastic yield d0 -- Present status -- After the SPU acceptance model was implemented, the normalization to the 4-ns 15w Al 5/17 data was within 10%. For this 14-ns 15e TiN 3/27 data, the normalization was high by a factor of 2, so the quantum efficiency has been halved in this simulation. The ratio of the first bunch signal to those of the witness bunches requires a reflectivity of 40% rather than 20%, consistent with SYNRAD3D. The model of the width of the witness bunch signals was improved by lowering the total secondary yield value from 1.0 to 0.8.