update on the kicker impedance model and measurements of material properties
DESCRIPTION
Update on the kicker impedance model and measurements of material properties. C. Zannini, G. Rumolo, V.G. Vaccaro Thanks to: N. Biancacci, A . Danisi, H. Day, G . De Michele , E. Metral, B. Salvant. Penetration depth in ferrite. Overview. Kicker impedance model Wire measurements - PowerPoint PPT PresentationTRANSCRIPT
Update on the kicker impedance model and measurements of material properties
C. Zannini, G. Rumolo, V.G. Vaccaro
Thanks to: N. Biancacci, A. Danisi, H. Day, G. De Michele, E. Metral, B. Salvant
Penetration depth in ferrite
Overview
• Kicker impedance model
• Wire measurements
• Measurements of material properties
4
Simplified kicker model Courtesy T. Kroyer
5
Simulation models
C-magnet model
x
y
6
Comparing the two models
Using the C-magnet model in the transverse horizontal impedance a high peak at 40MHz appears. At low frequency the Tsutsui model is not able to estimate correctly the kicker impedance. The two models are in good agreement at high frequency (>400MHz).
Real horizontal quadrupolar impedance calculated at x=1 cm
7
Comparing the two modelsIm
peda
nce
[Ohm
]
Real vertical detuning impedance calculated at y=0.5cm
Real longitudinal impedance
We can see the peak also in the longitudinal and vertical impedance
C-magnet and Frame magnet
C-magnet model
x
y
Frame Magnet model
C-magnet and Frame magnet
Penetration depth in ferrite
Calculation of the impedance for the C-Magnet model
TSUNSCMagnet ZZZ
Where is the low frequency impedance in a C-Magnet kicker model calculated using the Sacherer Nassibian formalism and is the impedance calculated using the Tsutsui formalism. The Tsutsui impedance is calculated in H. Tsutsui. Transverse Coupling Impedance of a Simplified Ferrite Kicker Magnet Model. LHC Project Note 234, 2000. Instead we have to spend some word about the Sacherer Nassibian impedance.This impedance is defined as:
NSZTSUZ
gk
kx||NS
k||NS
ZLjZZblc|Z
acZ
Zbl)ax(Z
2
220
02
2
220
20
2
4
4
0
Where l is the length of the magnet, x0 the beam position, L the inductance of the magnet and Zg is the impedance seen by the kicker
12
Comparing with theoretical results
The simulations of the C-magnet model are in agreement with a theoretical prediction based on Sacherer-Nassibian and Tsutsui formalism
Horizontal driving impedance calculated at x=1cm: MKP
Frame Magnet modelHorizontal dipolar impedance
External circuits EK PSB
The green curve depends from the cable properties (propagation and attenuation constants)
14
MKP: horizontal transverse impedance
The segmentation seems to affect strongly the low frequency peak
Overview
• Kicker impedance model
• Wire measurements
• Measurements of material properties
16
Measurements of the coupling impedance using the coaxial wire method
The measured quantity is the transmission S21
proptruem QQQ111
For resonant structures:
cut-off frequency ≠0cut-off frequency =0
TEM Propagation losses
Measured Losses = True Losses + Propagation losses
17
seg
MKP: Comparing measured and simulated longitudinal impedance
11628
50760076
steelPEC
steelPEC
mrad
mradtrue
radPEC
msteel
QQQQ
QQQQQ
.QQ.QQ
Measurements of the coupling impedance using the coaxial wire method
radtruem QQQ111
cut-off frequency =5.74 GHz
Superfish 11463trueQ
Measurements of the coupling impedance using the coaxial wire method
Overview
• Kicker impedance model
• Wire measurements
• Measurements of material properties
21
Coaxial line method
We characterize the material at high frequency using the waveguide method
Electromagnetic characterization of materials
)'','(GS 21
),(G
),(
),(
Status of the measurements
We (me and G. De Michele) did measurements for some SiC in the ranges 10 MHz-2GHz and 8 - 40 GHz and for the ferrite 8C11 in the range 10MHz-10GHz
The elaboration of the results will take at least one month (simulation time of the measurement setups)
23
Ferrite Model
The ferrite has an hysteresis loop
The hysteresis effect in this measurements
μ
H
rB
m/A.H 80 TB r610
In this measurements for the coaxial ferrite sample we have:
11
hysteresis
truemeasured