Longitudinal Impedance Studies of VMTSA

Slides:



Advertisements
Similar presentations
Effect of RFQ Modulations on Frequency and Field Flatness
Advertisements

RF Modeling efforts on Ion Source at SNS Sung-Woo Lee.
TDI longitudinal impedance simulation with CST PS A.Grudiev 20/03/2012.
Mathematical Models and Numerical Investigation for the Eigenmodes of the Modern Gyrotron Resonators Oleksiy KONONENKO RF Structure Development Meeting,
Update on the kicker impedance model and measurements of material properties V.G. Vaccaro, C. Zannini and G. Rumolo Thanks to: M. Barnes, N. Biancacci,
History and motivation for a high harmonic RF system in LHC E. Shaposhnikova With input from T. Argyropoulos, J.E. Muller and all participants.
Acknowledgements F. Caspers, H. Damerau, M. Hourican, S.Gilardoni, M. Giovannozzi, E. Métral, M. Migliorati, B. Salvant Dummy septum impedance measurements.
RF Cavity Design with Superfish
Agenda: General kickers analysis Wang-Tsutsui method for computing impedances Benchmarks Conclusions Bibliography Acknowledgments: E.Métral, M.Migliorati,
Update of the SPS transverse impedance model Benoit for the impedance team.
Higher-Order Modes and Beam-Loading Compensation in CLIC Main Linac Oleksiy Kononenko BE/RF, CERN CLIC RF Structure Development Meeting, March 14, 2012.
Update on BGV impedance studies Alexej Grudiev, Berengere Luthi, Benoit Salvant for the impedance team Many thanks to Bernd Dehning, Massimiliano Ferro-Luzzi,
Update on wire scanner impedance studies
Simulation of trapped modes in LHC collimator A.Grudiev.
RF Tutorial G Burt. TM 010 Monopole Mode E H Beam Z 0 =377 Ohms.
2 nd harmonic RF perpendicular biased cavity update C.Y. Tan, W. Pellico, G. Romanov, R. Madrak, and D. Wildman 02 Apr 2014.
Trapped Modes in LHC Collimator (II) Liling Xiao Advanced Computations Department SLAC National Accelerator Laboratory.
1 EuroTeV High Bandwidth Wall Current Monitor Alessandro D’Elia AB-BI-PI.
Longitudinal Impedance Characterization of the SPS MBA-QF Unshielded Pumping Ports Simulations, bead-pull and wire measurements Fritz Caspers, Jonas Ghini.
Update on TCTP heating H. Day, B. Salvant Acknowledgments: L. Gentini and the EN-MME team.
1 Update on the impedance of the SPS kickers E. Métral, G. Rumolo, B. Salvant, C. Zannini SPS impedance meeting - Oct. 16 th 2009 Acknowledgments: F. Caspers,
Update on new triplet beam screen impedance B. Salvant, N. Wang, C. Zannini 7 th December 2015 Acknowledgments: N. Biancacci, R. de Maria, E. Métral, N.
TESLA DAMPING RING RF DEFLECTORS DESIGN F.Marcellini & D. Alesini.
August 21st 2013 BE-ABP Bérengère Lüthi – Summer Student 2013
Longitudinal impedance of new RF fingers O. Berrig, C. Garion, B. Salvant.
Update on the TDI impedance simulations and RF heating for HL- LHC beams Alexej Grudiev on behalf of the impedance team TDI re-design meeting 30/10/2012.
Midterm Review 28-29/05/2015 Progress on wire-based accelerating structure alignment Natalia Galindo Munoz RF-structure development meeting 13/04/2016.
New Contributions to the SPS Longitudinal Impedance Model
F. Caspers, A. Grudiev, E. Métral, B. Salvant
The Cockcroft Institute and The University of Manchester
RF Dipole HOM Electromagnetic Design
Experience with CST Eigenmode Solver for the LHCb Velo Upgrade Project
Interpretation of resonant wire measurements on the TCSPM
Finemet cavity impedance studies
Simulation of 200 MHz RF cavities. 11 cells preliminary results
CLIC Main Linac Cavity BPM Snapshot of the work in progress
Update on HL-LHC triplet fingers
Benoit Salvant, Kyrre Sjobak, Christine Vollinger, Na Wang
Follow up on SPS transverse impedance
10 MHz amplifier status G. Favia
Update on the impedance studies of the SPS wirescanners
Development of a novel measurement technique for the Amorphous Carbon EM Characterization in the Sub-THz frequency range. A.Passarelli, A. Andreone,
Update on PS Longitudinal Impedance Model
News on the TMCI and SPS transverse impedance
CST simulations of VMTSA
Dummy septum impedance measurements
E. Métral, N. Mounet and B. Salvant
TCTP the CST side F. Caspers, H. Day, A. Grudiev, E. Metral, B. Salvant Acknowledgments: R. Assmann, A. Dallocchio, L. Gentini, C. Zannini Impedance Meeting.
News Request to install SLAC collimator in SPS
Beam impedance of 63mm VM with unshielded Bellows
ATF Fast Kicker R&D at LBNL ILCDR06, Cornell University
¼ meshed models for Omega3P calculations
Small step towards understanding bench measurements’ curves
Simulation of trapped modes in LHC collimator
Beam impedance of 63mm VM with unshielded Bellows
Impedance working group update 21st August 2013
Simulations and RF Measurements of SPS Beam Position Monitors (BPV and BPH) G. Arduini, C. Boccard, R. Calaga, F. Caspers, A. Grudiev, E. Metral, F. Roncarolo,
Origin of TCLIA/TCTV transverse BB impedance
Marco Panniello, Vittorio Giorgio Vaccaro, Naples.
HBP impedance calculations
Collimator design with BPMs (TCTP)
Status of the EM simulations and modeling of ferrite loaded kickers
Multiphysics simulations of impedance effects in accelerators
Impedance working group update 07th August 2013
EM Simulation of wakes in BSRT beampipe with extraction mirror
Update of the heating of ALFA detector in 2011
Origin of TCLIA/TCTV transverse BB impedance
Two beam coupling impedance simulations
Results on RF-Measurements on 3-Convolution HL-LHC fingers
PS KFA45_17 Wire Measurements and Simulation
Presentation transcript:

Longitudinal Impedance Studies of VMTSA O. Kononenko, B. Salvant, E. Métral LRFF Meeting, CERN, May 29, 2012

Introduction RF Fingers deformations => need simulations to study impedance problems HFSS – one of the best frequency domain solvers => accurate eigenvalue and s-parameters results (IF the convergence is controlled carefully) It is possible to take into account frequency dependent properties of ferrites We can cross-check the results with CST and measurements to see if we really understand the problem

RF Fingers Deformation in VMTSA

Setups to Be Simulated Conforming old fingers Conforming new fingers Wire, no fingers Bad contact 1st type Deformations, ferrites, etc Bad contact 2nd type Ferrites in, Philips 8C11

Conforming new RF Fingers HFSS Simulation Setup: Eigensolver Model: 180 deg of the structure copper outer wall Perfect H Copper Simulation profile: - second order basis functions curvilinear elements enabled 1% frequency accuracy leads to ~150K tet10 mesh, problems with mesh/convergence

Conforming New RF Fingers: CmplxMag(E) 0.1 V/m 0.12 V/m 0.012 V/m 0.014 V/m Mode 1 Mode 2 Mode 3 Mode 4 Mode 5 Looks like a numerical noise

Power Spectrum Measurements

Conforming New RF Fingers: Results Eigen Frequency, MHz Q-factor Shunt Impedance, Ω Power Loss,W HFSS CST Mode 1 549 550.3 6011 6770 0.008 0.03 0.001 Mode 2 550.4 6016 6790 0.014 0.002 Mode 3 886 829 6695 5930 515 ~0 X Mode 4 888 1085 7821 10310 242 0.15 0.0003 Mode 5 915 - 5127 20 HFSS convergence still to be checked, but conforming RF fingers look ok Longitudinal Shunt Impedance Voltage along beam path, including transit time factor Energy stored in the volume

New RF Fingers, 2nd Type Bad Contact HFSS Simulation Setup: Eigensolver Model: 180 deg of the structure copper outer walls 10mm gap Perfect H Copper 10 mm gap Simulation profile: - second order basis functions curvilinear elements enabled 1% frequency accuracy leads to ~300K tet10 mesh

New RF Fingers, 2nd Type Bad Contact CmplxMag(E) 0.113 V/m 0.037 V/m 0.030 V/m 0.005 V/m 0.028 V/m Mode 1 Mode 2 Mode 3 Mode 4 Mode 5 Eigenmodes of the Bellows

New RF Fingers, 2nd Type Bad Contact Results Eigen Frequency, MHz Q-factor Shunt Impedance, Ω Power Loss,W HFSS CST Mode 1 335 339 2372 32 49764 676 6449 87 Mode 2 519 531 1654 322 7343 1438 951 186 Mode 3 549 550 6324 6837 0.63 0.03 0.081 0.004 Mode 4 576 583 2823 155 762 7 99 0.907 Mode 5 657 - 1202 408 53 CST results (Q, R) look suspicious

VMTSA with Wire and No Fingers Model: 180 deg of the structure copper outer walls Perfect H Port 2 Copper Wire Port 1 Simulation profile: - second order basis functions curvilinear elements enabled 0.01 s-parameters accuracy => ~170K tet10 mesh discrete sweep from 20MHz to 2GHz, 10MHz step

Transmission: s21 Good agreement of the CST/HFSS/Measurements results Jean-Luc Nougaret, VMTSA measurements, December 2011-January 2012 Good agreement of the CST/HFSS/Measurements results

Conclusions Good experience simulating RF Fingers in HFSS Convergence still to be checked for some simulations It looks like CST gives incorrect Q-factors and shunt impedances. Convergence problem? Ferrites simulations must be accomplished Overall simulation strategy should be clearly understand We can move forward quickly