ciemat activities on stripline kickers i. rodríguez
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CIEMAT ACTIVITIES ON STRIPLINE KICKERS
I. Rodríguez
22
Outline
CTF3 Combiner Ring Kicker
CTF3 TL2 Tail Clippers
Stripline kickers in ILC
Conclusions
33
CTF3 Combiner Ring Kicker (1)
Kicker location in CTF3 Combiner Ring (CR)
Extraction of beam after 4-turns combination in the CR
Substitution of an old magnetic kicker to improve beam impedance
KICKER
44
CTF3 Combiner Ring Kicker (2)
Specifications to meet
±1% homogeneity is the most challenging specification
MAGNITUDE VALUE UNITS
Energy 300 MeV
Deflection Angle 8 mrad
Transverse voltage (V ) 2.4 MV
Rise/Fall-times (0-100%) ≤70 ns
Pulse length (max.) 200 ns
Flat-top reproducibility ±0.1 %
Flat-top stability (including droop) ±0.25 %
Repetition rate (Initial-Nominal) 5-50 Hz
Available length (flange to flange) 2000 mm
Vertical aperture ≥40 mm
Horizontal aperture ≥40 mm
Field homogeneity (±1%) 30 mm
55
CTF3 Combiner Ring Kicker (3)
Design and calculations Several cross sections considered. Planar electrodes
chosen
3D model in HFSS: 1.7 m electrodes. Good transmission of pulse frequency content
Wakefields studied using CST Particle Studio at CIEMAT and GDFidl at CERN
Aperture: 41 mmElectrode height: 44 mmTube radius: 54 mmBorder angle : 42ºBorder length : 8.2 mmElectrode width : 2 mmZ0 = 49.99 Ω
Homogeneity: ±0.74 %
|S11|2=<0.03% (0 to 50 MHz)
66
CTF3 Combiner Ring Kicker (4)
Manufacturing: Fully in stainless-steel Many high vacuum welds required
Challenging stand-off support Special beam pipe transitions
77
CTF3 Combiner Ring Kicker (5)
Testing Vacuum test and leak rate successful. Mild bake out
required High voltage pulser test: 16 kV, 5 ns, 50 Ohm load
DC high voltage test: 18 kV successfully tested (14 kV nominal)
RF tests
0 0.5 1 1.5 2 2.5 3 3.5
x 107
0
0.1
0.2
0.3
0.4
0.5
0.6
0.7
0.8
0.9
1S11 at low frequency: 0.3 to 35 MHz
Almost no reflection < 0.2% in power up to 35 MHz
0 1 2 3 4 5 6 7 8 9 10
x 108
0
0.1
0.2
0.3
0.4
0.5
0.6
0.7
0.8
0.9
1S11 low range: 0 to 1 GHz
0 5 10 15 20 25 30 35 40 45 50
0
0.2
0.4
0.6
0.8
Pulse directly to the load
Time (ns)
0 100 200 300 400 500 600 700 800 900 10000
0.02
0.04
0.06
0.08
Pulse frequency content
Frequency (MHz)
0 5 10 15 20 25 30 35 40 45 50
0
0.2
0.4
0.6
0.8
Pulse over first strip-line
Time (ns)
0 100 200 300 400 500 600 700 800 900 10000
0.02
0.04
0.06
0.08
Pulse frequency content
Frequency (MHz)
88
CTF3 TL2 Tail Clippers (1)
Tail Clippers location in CTF3
Shorten the bunch trains for conditioning before PETS
Extremely fast response required to precisely cut the beam between bunches
TAIL CLIPPERS
99
CTF3 TL2 Tail Clippers (2)
Specifications to meet
High frequency transmission is the most challenging specification
Beam energy 200 MeV
Total kick deflection angle 1.2 mrad
Deflection plane vertical
Stripline plate separation 40 mm
Field homogeneity ±20 %
Characteristic impedance 50 ±1 Ohms
Pulse duration (maximum) 200 ns
Maximum field rise-time (0.25 to 99.75%) 3 ns
Maximum timing jitter 1 ns
Pulse repetition rate – nominal/maximum 5 / 50 Hz
Number of stripline sections 4
Stripline section length (between centre's of feedthroughs) 300 mm
Total available straight section length 1625 mm
Pumping ports none
Supports and Alignment system as per CR kicker
1010
CTF3 TL2 Tail Clippers (3) Design and calculations
Several cross sections considered
Smooth coax to stripline transitions for enhanced RF transmission
Excellent high frequency transmission up to 2 GHz Homog:±19%
Ø 66 mmHomog:±15%Ø 71 mm
Homog:±10%Ø 78 mm
1111
CTF3 TL2 Tail Clippers (4) Manufacturing
Stainless steel tube and aluminium electrodes
Electrodes fully manufactured using CNC High voltage 50 Ohm feedthroughs Challenging coax to stripline connections
1212
CTF3 TL2 Tail Clippers (5)
Testing Excellent leak test. Good vacuum. Mild bake-out
required High voltage pulser test. Excellent behaviour at high
freqs
DC high voltage test: 3 kV successfully tested (2 kV nominal)
RF tests
0 100 200 300 400 500 600 700 800 900 10000
0.1
0.2
0.3
0.4
0.5
0.6
0.7
0.8
0.9
1S parameters at medium frequency: 2 to 1000 MHz
Freq.(MHz)
S p
aram
eter
S11
S21
-1 0 1 2 3 4 5
x 10-7
-4000
-3000
-2000
-1000
0
1000
2000
3000
4000Pulse response of Tail Clipper 2 using 130 ns pulse
Time (s)
Vol
tage
-50 0 50 100 150 200 250 300 350 400 4500
1000
2000
3000
400020 ns pulse directly to the load
Time (ns)
0 20 40 60 80 100 120 140 160 180 2000
100
200
300Pulse frequency content
Frequency (MHz)
-50 0 50 100 150 200 250 300 350 400 4500
1000
2000
3000
400020 ns pulse passing through Strip2 of TailClipper 2
Time (ns)
0 20 40 60 80 100 120 140 160 180 2000
100
200
300Pulse frequency content
Frequency (MHz)
1313
ILC stripline kickers
Many stripline kickers in different zones: DRs, RTML, etc
Most challenging ones: Damping Ring injection and extraction kickers. DRs 6.7 km, 5 GeV.
The electrical pulser requirements are extremely challenging.
MAGNITUDE VALUE*
Number of modules in DRs
21 (injection)11 (extraction)
Length 0.3 m
Voltage ±11 kV
Bunch spacing 3 ns
Pulse width < 4 ns
Pulse repetition rate 150 ns (6.6 MHz)
* ILC Reference Design Report (August, 2007)
-1
0
1
2
3
4
5
6
-5 10-9 0 5 10-9 1 10-8
FID(FPG-3000M) Waveform
Volt
age(
kV
)
Time(s)
1414
Conclusions
Two stripline kickers have been fully designed, manufactured and tested. Tail Clipper power supplies were designed at CERN.
ILC kickers are very similar except from the pulsed power supply.
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