Single cell standing wave tests data analysis Jiaru Shi Sep 27, 2011 LCWS11, Granada, Spain

Introduction Many single cell structures were tested at SLAC – Valery Dolgashev – To study RF breakdown with different geometries and different materials Many thanks to Valery Dolgashev, Yasuo Higashi Analysis data of single cell SW LCWS11, Granada, Spain

Note: To calculate field from recorded input power LCWS11, Granada, Spain

Note: [SLAC-R-577]Pulsed surface heating, 1D solution New quantity: LCWS11, Granada, Spain

One-C-SW-A2.75-T2.0-Cu-SLAC-#1 Same surface electric field PinStored energy Max E surface E acc E surface, max E acc E surface, max X Eacc pi-mode LCWS11, Granada, Spain

Equivalent pulse width Equivalent square pulse: same max (Iα) LCWS11, Granada, Spain

600ns flat 200ns flat 400ns flat 150ns flat LCWS11, Granada, Spain

Plot corr^2 LCWS11, Granada, Spain

One-C-SW-A3.75-T2.6-Cu-SLAC-#1 one-c-SW-A5.65-T4.6-Cu-Frascati-#2 One-C-SW-A5.65-T4.6-Cu-KEK-#2 LCWS11, Granada, Spain

Summary plot LCWS11, Granada, Spain

Scaling t flat + 80nsEquiv. t pulse Eacc (MV/m) StdSqrt(Sc6)Eacc (MV/m) StdSqrt(Sc6) A2.75T2.0 SLAC# % %2.36 A3.75T2.6 SLAC# % %2.26 A5.65T4.6 Frascati# % %2.03 A5.65T4.6 KEK# % %2.27 Eacc scaled to tp=200ns, bdr=1e-6/pulse/m tp^(-1/6) BDR^(1/30) LCWS11, Granada, Spain

Summary BDR.v.s. (W --- stored energy) Best alpha between 0.5 ~ 0.7 for this four structure. (0.5 for pulsed surface heating) Equivalent pulse width calculated for standing wave structure with relatively long rising time More structures. New function? LCWS11, Granada, Spain