FCChh Coating and Impedance Patrick Krkoti Uwe Niedermayer

FCC-hh Coating and Impedance Patrick Krkotić, Uwe Niedermayer, Oliver Boine-Frankenheim 18. 09. 2020 | TU Darmstadt | TEMF | Patrick Krkotić |

Content Introduction Impedance High Temperature Superconductor Coating 18. 09. 2020 | TU Darmstadt | TEMF | Patrick Krkotić | 2

Introduction Beam screen design screen Temperature 50 K Material titanium pipe copper coating of 300 μm Carbon coating e-clouds – secondary emission yield High Temperature Superconductor coating sufficient small beam impedance C. Garion, FCC-hh beam screen studies and cooling scenario, FCC week 2016, Rome 18. 09. 2020 | TU Darmstadt | TEMF | Patrick Krkotić | 3

Impedance Calculation Beam Screen : 2 D impedance simulation (BI 2 D) BI 2 D: 2 D frequency domain solver Computational tool for longitudinal and transverse coupling impedance Finite-Element-Method (FEM) Input: mesh of the geometry Two methods: 1. Surface Impedance Boundary Condition (SIBC) 2. Meshing whole Structure range of skin frequency * ‘Space charge and resistive wall impedance computation in the frequency domain using the finite element method’ Niedermayer, Boine-Frankenheim and De Gersem PRSTAB 18, 032001 (2015) 18. 09. 2020 | TU Darmstadt | TEMF | Patrick Krkotić | 4

Copper Coating Resistive Wall Impedance - transversal preliminary results 18. 09. 2020 | TU Darmstadt | TEMF | Patrick Krkotić | 5

Copper Coating Resistive Wall Impedance - longitudinal preliminary results 18. 09. 2020 | TU Darmstadt | TEMF | Patrick Krkotić | 6

HTS Coating Surface Impedance Perfect electric conducting boundary 18. 09. 2020 | TU Darmstadt | TEMF | Patrick Krkotić | 7

HTS Coating Magnetic Field 18. 09. 2020 | TU Darmstadt | TEMF | Patrick Krkotić | 8

HTS Coating Magnetic Field 18. 09. 2020 | TU Darmstadt | TEMF | Patrick Krkotić | 9

HTS Coating Magnetic Field – Vortex 18. 09. 2020 | TU Darmstadt | TEMF | Patrick Krkotić | 10

HTS Coating Magnetic Field – Vortex Properties Parallel to c -axix Parallel to ab -plane ~0. 2 to 0. 3 ~1. 5 to 2. 0 150 750 104 106 150 30 0. 41 nm Ba Cu 0. 34 nm Y W. Buckel, Supraleitung Grundlagen und Anwendung, Wiley-VCH Verlag Gmb. H & Co. KGa. A a c 0. 41 nm b b O a 0. 38 nm 18. 09. 2020 | TU Darmstadt | TEMF | Patrick Krkotić | 11 b 0. 39 nm

HTS Coating Magnetic Field – Vortex 18. 09. 2020 | TU Darmstadt | TEMF | Patrick Krkotić | 12

HTS Coating Magnetic Field – Vortex distorsion of magnetic field Prof. Ruggero Vaglio - Naples University 18. 09. 2020 | TU Darmstadt | TEMF | Patrick Krkotić | 13 N. Plakida, High-Temperature Cuprate Superconductors, Spinger Heidelberg

HTS Coating Magnetic Field – Vortex-flow distortion of magn. field Prof. Ruggero Vaglio - Naples University 18. 09. 2020 | TU Darmstadt | TEMF | Patrick Krkotić | 14 flux-flow surface impedance Y. B. KIM, C. F. HEMPSTEAD AND A. R. STRNAD, Flux-Flow Resistance in Type-II Superconductors Bell Telephone Laboratories, Murray Hill, New Jersey

HTS Coating Conclusion Question: What value has the distortion of the magnetic field? Assumption: not applicable for HTS coating § magnetic field lines strongly bent Pancake Vortex § thin stripes and small width § stronger magnetic filed more vortex less distortion § Pinning is important random vortices can be ordered laser deposition or ion irradiation § no impact on beam - ‚magnetic field distortion‘ § lower surface impedance 18. 09. 2020 | TU Darmstadt | TEMF | Patrick Krkotić | 15 § Current Bean model – critical current just vortex currents

Outlook Surface Resistance HTS Coating § Magnetic distortion and pinning effects § Including the impedance in BI 2 D § Persistent current in YBCO FCC Library Part I - surface impedance Part II - beam impedance 18. 09. 2020 | TU Darmstadt | TEMF | Patrick Krkotić | 16

Thank you for your attention! Any questions? 18. 09. 2020 | TU Darmstadt | TEMF | Patrick Krkotić | 17

HTS Coating normal dc-conductivity 77 K Buckel, Werner: Supraleitung, Grundlagen und Anwendungen, 7. Auflage, Wiley-VHC Verlag Gmb. H & Co. KGa. A, 2013 18. 09. 2020 | TU Darmstadt | TEMF | Patrick Krkotić | 18 Hein, Matthias: High-Temperature-Superconductor Thin Films at Microwave Frequencies, Springer-Verlag Berlin Heidelberg (1999)