Mitglied der Helmholtz Gemeinschaft 7 th Georgian German

Mitglied der Helmholtz. Gemeinschaft 7 th Georgian – German School and Workshop in Basic Science - GGSWBS'16 Waveguide RF Wien Filter for EDM@COSY Helmut Soltner Central Institute of Engineering, Electronics and Analytics (ZEA-1) Tblissi, September 1 st, 2016

Outline • • • Introduction: principle of a static Wien filter Design of the Waveguide RF Wien Filter • Mechanical Design • Electromagnetic field simulations • External circuits • Control scheme at COSY Timeline for implementation 2

Principle of a static Wien filter Orthogonal fields Lorentz force vanishes for a specific particle velocity Source: Wikipedia 3

Introduction EDM experiment in the storage ring use an RF technique: • RF Wien filter operates on harmonics of the spin precession frequency • accumulate EDM signal with time 4

Principle of an rf Wien filter as described in 2014 5

Some features of the rf Wien filter support for geodetics inner support tube support structure for electrodes Ferrit cage RF feedthrough BPM (Rogowski coil) beam pipe (CF 100) copper electrodes ferrite cage Mechanical support vacuum vessel with small-angle rotation clamps for the ferrite cage The goal is to build the best possible device with respect to electromagnetic performance, mechanical tolerances, etc. 6

Internal structure of the rf Wien filter ceramic insulators copper electrodes with the trapezium shaping at the edges sliding connector to RF mechanical support for electrodes clamps supporting the ferrite cage inner support tube Design completed, manufacturing of parts finished September 2016, assembly in ZEA clean room starts in October 2016. 7

Internal structure of the rf Wien filter ceramic insulators copper electrodes mechanical support for electrodes Design completed, manufacturing of parts finished September 2016, assembly in ZEA clean room starts in October 2016. 8

Drawings for manufacture Cross section of rf Wien filter 9

Drawings for manufacture Shape of the electrode Elliptical shape of the electrode 10

Driving circuit Realization as a strip line with a load resistor and tuning elements (L & C). Example of a matching network Courtesy Barthel hf-Technik Gmb. H, Aachen Input power ≈ 10 k. W Design layout using four separate power amplifiers of circuit 11

The waveguide RF Wien filter Device will be installed in PAX low-β section 12

Electromagnetic field simulations Simulation results by RWTH Aachen 13

Lorentz force compensation Minimal integral Lorentz forces require careful shaping of electrodes and all the other components Z=Ex/Hy=173 W 14

Control loops imbedding the rf Wien filter in COSY Realization as a strip line with a load resistor and tuning elements (L/C). Feedback loops involve components of the whole COSY ring 15

Time line • Assembly: October 2016 – presumably without ferrite blocks • Integration with COSY: November 2016 • Commisioning: First tests at COSY in winter 2016/17. 16

Joint publication by contributors • Idea and specifications for rf Wien filter, Jülich, IKP • Electromagnetic design: RWTH Aachen, Institute of High-Frequency Technology • Mechanical and thermal design: Jülich, ZEA-1 17

Thank you for listening! 18