1. Theoretical and Experimental studies on energy transfer in Couplers for Superconducting RF Cavities Nawin Juntong 20-December-2007

2. National Synchrotron Research Center is a research institute operating the Siam Photon Source (SPS), a 1.2 GeV synchrotron light source. Where I come from? - Photoemission Spectroscopy - X-Ray Lithography - X-ray Absorption Spectroscopy

3. Pictures from - Peter McIntosh, ERLP and 4GLS at Daresbury, SRF2007,Beijing (15-19 Oct 2007) and XFEL website My Work ERLP Cryomodule @ Daresbury XFEL Coupler High peak power, pulsed operation 7-cell 1.3GHz TESLA type Cornell Coupler High average power CW

4. -Study of specifications and performances (Thermal and RF) on a different RF coupler designs. -Use RF codes, HFSS, GdfidL and ECHO 2D,to determine EM fields properties, wakefields, wake potential, loss factors and kick factors. -Experimental Tests of Coupler Kicks on ERLP. Scope of Work Work Schedule January – February 2008 - Understand cleanroom procedures and assist with the cleaning and assembly of XFEL Coupler and participate in RF testing. January – June 2008 - Assess the Antenna shape and coupling effects of different Antenna designs. June 2008 – December 2009 - Assessment of Coupler kicks, calculations and experiments October-December 2007 - Use HFSS code calculate mode frequencies on monopole and dipole modes of TESLA type cavity. - Apply circuit model theory on this simulation.

5. Simulation Results TypeBand # f 0/GHz f p/GHz PaperResultsDiff. /MHz PaperResultsDiff. /MHz M11.27551.276901.401.29961.301191.59 D11.61971.619410.291.79201.795493.49 D21.88771.891673.971.82611.825560.54 M22.45762.459892.292.37892.380561.66 D32.57822.581263.062.47132.472641.34 M32.67042.673192.792.77302.775812.81 D43.03333.035312.012.81342.818435.03 D53.12313.123320.223.08023.080730.53 D63.34193.346854.953.35953.364575.07 M43.66033.665294.993.38713.392255.15 0.16% HFSS 8.5 results comparison with Wanzenberg paper. Simulation on TESLA mid cell geometry. M=Monopole, D=Dipole

6. Circuit model theory Single chain Double chain Coupling between TE and TM field Only TE or TM field

7. HFSS 8.5Single Chain Circuit model 1stband2ndband3rdband1stband2ndband3rdband Phase diff.F(GHz) Diff(MHz)F(GHz)Diff(MHz)F(GHz)Diff(MHz) 01.276902.459892.673191.276900.002.459890.002.673190.00 301.278512.452852.681281.278480.032.454331.482.679711.57 601.282882.435772.701901.282840.042.439323.552.697774.13 901.288942.415342.727681.288870.072.419253.912.723054.63 1201.295052.397222.752071.294990.062.399672.452.749053.02 1501.299542.384902.769461.299520.022.385640.742.768560.90 1801.301192.380562.775811.301190.002.380560.002.775810.00 Max.Diff (%) 0.0054 0.1619 0.1697 HFSS 8.5Single Chain Circuit model 4thband5thband6thband4thband5thband6thband Phase diff.F(GHz) Diff(MHz)F(GHz)Diff(MHz)F(GHz)Diff(MHz) 03.665293.755463.921333.665290.003.755460.003.921330.00 303.619663.793033.934893.6449025.243.7621030.933.940395.50 603.550643.831833.983083.5909040.263.7804251.413.9939010.82 903.487193.848344.058693.5208533.663.8058842.464.0706511.96 1203.436653.854914.140323.4547618.113.8318623.054.1520011.68 1503.403693.857604.208933.408674.983.851226.384.214745.81 1803.392253.858384.238433.392250.003.858380.004.238430.00 Max.Diff (%) 1.1339 1.3417 0.2947 Apply Circuit model Theory Monopole mode - use single chain model

8. HFSS 8.5 Circuit model 1st band2nd band1st band2nd band PhaseF(GHz) Diff(MHz)F(GHz)Diff(MHz) 01.619411.891671.619410.001.891670.00 301.627271.890481.627580.311.890210.27 601.649561.886521.650971.411.885570.95 901.683961.879231.686282.321.877002.23 1201.725301.865501.728112.811.863302.20 1501.767641.844911.769471.831.843481.43 1801.795491.825561.795490.001.825560.00 Max.Diff (%) 0.1629 0.1187 TE TM TE Dipole mode – use double chain model

9. Dispersion Curves Red-Monopole Blue-Dipole

10. -END- Thank you