various approaches to electromagnetic field simulations for rf cavities
DESCRIPTION
Various approaches to electromagnetic field simulations for RF cavities. Cong Liu, Wolfgang F.O. Müller, Wolfgang Ackermann, Thomas Weiland Institut für Theorie Elektromagnetischer Felder ( TEMF), TU Darmstadt. - PowerPoint PPT PresentationTRANSCRIPT
22.04.2023 | TU Darmstadt | Fachbereich 18 | Institut Theorie Elektromagnetischer Felder | Dip.-Ing. Cong Liu | 1
Various approaches to electromagnetic field simulations for RF cavitiesCong Liu, Wolfgang F.O. Müller, Wolfgang Ackermann, Thomas WeilandInstitut für Theorie Elektromagnetischer Felder (TEMF), TU Darmstadt
First Open Collaboration Meeting on Superconducting Linacs for High Power Proton Beams (SLHiPP-1)
22.04.2023 | TU Darmstadt | Fachbereich 18 | Institut Theorie Elektromagnetischer Felder | Dip -Ing. Cong Liu | 2
Outline
▪ Field simulation with hexahedron mesh in time domain
▪ Field simulation with hexahedron mesh in frequency domain
▪ Field simulation with tetrahedral mesh and higher order curvilinear elements
▪ Conclusion and Outlook
22.04.2023 | TU Darmstadt | Fachbereich 18 | Institut Theorie Elektromagnetischer Felder | Dip.-Ing. Cong Liu | 3
Field Simulation with Hexahedron Mesh in Time Domain
SPL Cavity 704.4MHz
Calculation of eigenmodes frequencies and shunt impedances with Transient Solver in CST MICROWAVE STUDIO®
22.04.2023 | TU Darmstadt | Fachbereich 18 | Institut Theorie Elektromagnetischer Felder | Dip.-Ing. Cong Liu | 4
Field Simulation with Hexahedron Mesh in Time Domain
Detect and record the electromagnetic field in time domain
22.04.2023 | TU Darmstadt | Fachbereich 18 | Institut Theorie Elektromagnetischer Felder | Dip.-Ing. Cong Liu | 5
Field Simulation with Hexahedron Mesh in Time Domain Eigenmode Spectrum TM110 Passband
f = 703.755 MHzTM010, 5/5π
Field Simulation with Hexahedron Mesh in Time Domain
Field Monitor in Transient Solver can be definedThe field data of eigenmodes can be achieved after the second simulation
22.04.2023 | TU Darmstadt | Fachbereich 18 | Institut Theorie Elektromagnetischer Felder | Dip.-Ing. Cong Liu | 6
E
Meshcells = 50 Million
TM010, 5/5π f = 703.755 MHz
22.04.2023 | TU Darmstadt | Fachbereich 18 | Institut Theorie Elektromagnetischer Felder | Dip.-Ing. Cong Liu | 7
Field Simulation with Hexahedron Mesh in frequency Domain
Hex Mesh 12 Million
Hex Mesh 6 Million
Hex Mesh 4.5 Million
Hex Mesh 2 Million
Hex Mesh 0.5 Million
Hex Mesh 0.1 Million
Eigenmodes frequencies convergence in TM010 Passband
Frequency / MHz
TM010, 1/5π TM010, 2/5π TM010, 3/5π TM010, 4/5π TM010, 5/5π
688 690 692 694 696 698 700 702 704 706
704.33
Calculation of eigenmodes frequencies and shunt impedances with Eigenmode Solver in CST MICROWAVE STUDIO®
22.04.2023 | TU Darmstadt | Fachbereich 18 | Institut Theorie Elektromagnetischer Felder | Dip.-Ing. Cong Liu | 8
Field Simulation with Hexahedron Mesh in frequency Domain
Slow convergence of frequency and shunt impedance (R/Q) !
Hex Mesh 12 Million
Hex Mesh 6 Million
Hex Mesh 4.5 Million
Hex Mesh 2 Million
Hex Mesh 0.5 Million
Shunt Impedance (R/Q) / Ω
Shunt Impedance (R/Q) convergence for TM010, 5/5π
561 562 563 564 565 566
565.089
22.04.2023 | TU Darmstadt | Fachbereich 18 | Institut Theorie Elektromagnetischer Felder | Dip.-Ing. Cong Liu | 9
Field Simulation with Tetrahedral Mesh and Higher Order Curvilinear ElementsSymmetric tetrahedral mesh grids
22.04.2023 | TU Darmstadt | Fachbereich 18 | Institut Theorie Elektromagnetischer Felder | Dip.-Ing. Cong Liu | 10
Field Simulation with Tetrahedral Mesh and Higher Order Curvilinear ElementsFast convergence of frequency
Tet Mesh 6 Million
Tet Mesh 4.5 Million
Tet Mesh 2 Million
Tet Mesh 1 Million
Tet Mesh 0.5 Million
Tet Mesh 0.1 Million
Frequency / MHz
TM010, 1/5π TM010, 2/5π TM010, 3/5π TM010, 4/5π TM010, 5/5π
688 690 692 694 696 698 700 702 704 706
704.39764
Eigenmodes frequencies convergence in TM010 Passband
22.04.2023 | TU Darmstadt | Fachbereich 18 | Institut Theorie Elektromagnetischer Felder | Dip.-Ing. Cong Liu | 11
Field Simulation with Tetrahedral Mesh and Higher Order Curvilinear ElementsFast convergence of shunt impedance (R/Q)
Tet Mesh 6 Million
Tet Mesh 4.5 Million
Tet Mesh 2 Million
Tet Mesh 1 Million
Tet Mesh 0.5 Million
Tet Mesh 0.1 Million
Shunt Impedance (R/Q) / Ω564 565 566 567
565.452
Shunt Impedance (R/Q) convergence for TM010, 5/5π
22.04.2023 | TU Darmstadt | Fachbereich 18 | Institut Theorie Elektromagnetischer Felder | Dip.-Ing. Cong Liu | 12
Field Simulation with Tetrahedral Mesh and Higher Order Curvilinear ElementsFast convergence of HOM’s frequencies
Tet Mesh 6 Million
Tet Mesh 4.5 Million
Tet Mesh 2 Million
Tet Mesh 1 Million
Tet Mesh 0.5 Million
Tet Mesh 0.1 Million
Frequency / GHz
TM110, 3/5π TM110, 4/5π TM110, 5/5π
1.012 1.014 1.016 1.018 1.022 1.024 1.025
Eigenmodes frequencies convergence in TM110 Passband
22.04.2023 | TU Darmstadt | Fachbereich 18 | Institut Theorie Elektromagnetischer Felder | Dip.-Ing. Cong Liu | 13
Field Simulation with Tetrahedral Mesh and Higher Order Curvilinear ElementsHOM’s mode with higher R/Q values (β = 1)
Monopole modes (Longitudinal R/Q) Mode f [MHz] R/Q [Ω]
TM011, 1/5π 1335.696481 104.388TM011, 2/5π 1329.385480 57.364200TM011, 3/5π 1317.323444 10.835400
Dipole modes (Transversal R/Q) Mode f [MHz] R/Q [Ω/m]
TE111, 3/5π 917.86077673 40.9000TE111, 4/5π 943.04379569 67.6544TE111, 5/5π 968.86849368 19.2868TM110, 2/5π 1004.05346947 20.3753TM110, 3/5π 1015.05261715 37.7503
22.04.2023 | TU Darmstadt | Fachbereich 18 | Institut Theorie Elektromagnetischer Felder | Dip.-Ing. Cong Liu | 14
Field Simulation with Tetrahedral Mesh and Higher Order Curvilinear ElementsComparison with the Hexahedron Mesh method in frequency domain
Hex Mesh 0.1MHex Mesh 0.5 MillionHex Mesh 2 MillionHex Mesh 4.5 MillionHex Mesh 6 MillionHex Mesh 12 MillionTet Mesh 6 MillionTet Mesh 4.5 MillionTet Mesh 2 MillionTet Mesh 1 MillionTet Mesh 0.5 MillionTet Mesh 0.1 Million
689 691 693 695 697 699 701 703 705
TM010, 1/5π TM010, 2/5π TM010, 3/5π TM010, 4/5π TM010, 5/5π
Frequencies convergences of eigenmodes in TM010 Passband
Frequency / MHz
22.04.2023 | TU Darmstadt | Fachbereich 18 | Institut Theorie Elektromagnetischer Felder | Dip.-Ing. Cong Liu | 15
Field Simulation with Tetrahedral Mesh and Higher Order Curvilinear Elements
Time needed to calculate the eigenmodes in TM010 Passband
Frequency of TM010, 5/5π / MHz704.15 704.20 704.25 704.30 704.35 704.40
103
102
101
100
Tim
e ne
eded
for s
imul
atio
n / M
in
22.04.2023 | TU Darmstadt | Fachbereich 18 | Institut Theorie Elektromagnetischer Felder | Dip -Ing. Cong Liu | 16
Conclusion and Outlook
• The eigenmode analysis with hexahedral mesh grids in frequency domain and time domain are not ideal approaches to electromagnetic field simulations for elliptical SPL cavity.
• The eigenmode analysis with tetrahedral mesh grids and higher order curvilinear elements is highly efficient and accurate.
22.04.2023 | TU Darmstadt | Fachbereich 18 | Institut Theorie Elektromagnetischer Felder | Dip -Ing. Cong Liu | 17
Conclusion and Outlook
• The frequencies and the shunt impedances of higher order modes up to 3GHz will be calculated accurately.
• The HOM coupler will be considered for the effective damping of higher order modes in the SPL cavity.
Thank you for your attention!