Work progress Nawin Juntong

Overall - Searching for the theory of RF coupler kick calculation. - Detailed of Dr. G. Burt method and others. - ABCI and ECHO 2D comparison.

1.Combine 2 SW fields to get TW fields 2.Integrate Lorentz force to get the change of momentum 3.Transverse kick factor is a ratio of the change of transverse momentum to the change of longitudinal momentum How to calculate kick factor (Dr. G.Burt method) PEC bc. PMC bc.

1.Combine 2 SW fields to get TW fields 2.Integrate Lorentz force to get the change of momentum 3.Transverse kick factor is a ratio of the change of transverse momentum to the change of longitudinal momentum How to calculate kick factor (B. Buckley and G.H. Hoffstaetter method) MWS from fields theis ˆ A PRST-AB 10,111002(2007),Cornell-ERL-06-02

Some Methods to Calculate Rf-Coupler Fields in Accelerating Cavities 1. Cavity Operation 2. Particle Dynamics 3. EM Field calculation a bit more recent: f.i. Darmstadt Feb not about solvers but about setups to be solved: SW solution TW solution (with and without beam) accelerating mode discrete resonator model steady state field EM fields (two solutions required) normalized kick tracking port

TTF-Style Coupler Mesh (lines/λ) Mesh (cells) cells run Mesh (lines/λ) Mesh (cells) cells run Non identical cells

ECHO 2D VS ABCI Simulation TESLA type cavity is simulated with 2 different Gaussian bunch sigmas; 0.7 mm and 1 mm. TESLA – CDR (σ z = 0.7mm) Longitudinal loss factor (  L ) 10.2 V/pC Transverse loss factor (  T )15.1 V/pC/m TTF – DR (σ z = 1mm) HOM loss factor (  L )9.24 V/pC (σ z = 0.7mm)ECHO 2DABCI ParametersDefault meshMore mesh 1 Mesh 3 Longitudinal loss factor (  L ) V/pC V/pC11.82 V/pC Transverse loss factor (  T ) V/pC/m V/pC/m15.61 V/pC/m (σ z = 1mm) ECHO 2DABCI Default meshMore mesh 2 Mesh 3 Longitudinal loss factor (  L ) V/pC9.905 V/pC10.04 V/pC Transverse loss factor (  T ) V/pC/m- V/pC/m18.52 V/pC/m

NEXT Re-calculate rf coupler kick using Buckley and Hoffstaetter method.