single cell standing wave tests data analysis jiaru shi sep 27, 2011 lcws11, granada, spain
TRANSCRIPT
LCWS11, Granada, Spain
Single cell standing wave testsdata analysis
Jiaru ShiSep 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
Pin Stored energy Max E surface
Eacc
Esurface, max
Eacc
Esurface, max
X Eacc
pi-mode
LCWS11, Granada, Spain
LCWS11, Granada, Spain
Equivalent pulse width
Equivalent square pulse: same max (Iα)
LCWS11, Granada, Spain
600nsflat
200nsflat
400nsflat 150ns
flat
LCWS11, Granada, Spain
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-#2One-C-SW-A5.65-T4.6-Cu-KEK-#2
LCWS11, Granada, Spain
LCWS11, Granada, Spain
LCWS11, Granada, Spain
LCWS11, Granada, Spain
Summary plot
0.3 0.4 0.5 0.6 0.7 0.80.1
0.2
0.3
0.4
0.5
0.6
0.7
0.8
0.9
alpha
corr
2
One-C-SW-A2.75-T2.0-Cu-SLAC-#1, 19 ptsOne-C-SW-A3.75-T2.6-Cu-SLAC-#1, 28 ptsOne-C-SW-A5.65-T4.6-Cu-KEK-#2, 22 ptsone-c-SW-A5.65-T4.6-Cu-Frascati-#2, 14 ptsE acc
LCWS11, Granada, Spain
Scaling
t flat + 80ns Equiv. t pulse
Eacc (MV/m)
Std Sqrt(Sc6) Eacc (MV/m)
Std Sqrt(Sc6)
A2.75T2.0 SLAC#1 142 4.8% 2.42 139 4.8% 2.36
A3.75T2.6 SLAC#1 111 7.0% 2.3 108 6.8% 2.26
A5.65T4.6 Frascati#2 85.7 3.5% 2.06 84.7 3.8% 2.03
A5.65T4.6 KEK#2 99.1 8.3% 2.38 94.7 5.3% 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?