DDS design status Task 9.2-Sub-task 2 Alessandro D’Elia on behalf of Roger M. Jones 1
DDS design status Task 9.2-Sub-task 2
Feb 24, 2016
DDS design status Task 9.2-Sub-task 2 . Alessandro D’Elia on behalf of Roger M. Jones. CLIC_DDS_A. PRELIMINARY. CLIC_DDS_B. Analysis of structures with different phase advances: 5 /9 and 5 /6 in comparison with the standard 2 /3 - PowerPoint PPT Presentation
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1
DDS design statusTask 9.2-Sub-task 2
Alessandro D’Elia on behalf of Roger M. Jones
2
CLIC_DDS_A
PREL
IMIN
ARY
3
CLIC_DDS_B• Analysis of structures with different phase advances: 5/9 and
5/6 in comparison with the standard 2/3• The basic idea is to explore if we can find a compromise between a
possible larger bandwidth (5/9) to the detriment of higher kicks or lower kicks (5/6) to the detriment of a smaller bandwidth
New Design: better but still not in the limits
4
Comparative tablesParameters 5/9 2/3 5/6
a (mm) in/out 3.8/1.8 3.95/1.94 4.3/2.4
<a >/ 0.112 0.118 0.134
a/<a> 0.357 0.341 0.284
t (mm) in/out 3.3/0.7 4/1 4/2.5
eps 1.5/2 1.5/2 2/2
nb x 109 4.59 4.69 5.05
bX (m-2) 1.506 1.518 1.562
Hs/Ea (mA/V) (first cell) 5.027 4.993 4.951
Es/Ea (last cell) 1.666 1.721 1.619
/2 (GHz) 2.537 2.508 2.237
Ksyn (V/pC/mm/m) in/out 15.142/111.136 41.905/84.182 32.48/54.594
Av. Cross (MHz) in/out 755/811 679/759 609/761
Vg (%c) in/out 2.282/0.505 2.041/0.473 1.933/0.281
R/Q (k/m) in/out 10.779/23.342 9.975/20.522 9.202/14.857
Pin (MW) 75 75 75
Eacc (MV/m) (first cell) 94.4 96 94.7
5
0 0.5 1 1.5 2 2.5 3 3.5 4 4.5 510
-2
10-1
100
101
102
s (m)
Wak
e (V
/[pC
mm
m])
GdfidL wakeWake limitFirst Dipole Wake <Q>=205First Dipole Wake <Q>=14
2/3
0 0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8 0.9 110
-2
10-1
100
101
102
s (m)
Wak
e (V
/[pC
mm
m])
GdfidL wakeWake limitFirst Dipole Wake <Q>=205First Dipole Wake <Q>=14
To efficiently damp the first trailing bunch staying this detuning (~2.5GHz), we would need a <Q>~14
Linear tapering
610 15 20 25 30 35 40 45 500
1
2
3
4
5
6x 10
4
freq (GHz)
Abs
(Zx) (
/[m
m m
])
10 20 30 40 50-2
0
2
4
6x 10
4
freq (GHz)
Real
(Zx) (
/[m
m m
])
10 20 30 40 50-4
-2
0
2
4
6x 10
4
freq (GHz)
Imag
(Zx) (
/[m
m m
])
0 2 4 6 8 1010
0
101
102
s (m)
Wak
e (V
/[pC
mm
m])
Quite high kicks and a very high-Q resonance in the 5th-7th bands
5/9
Linear tapering
7
0 50 100 150
15
20
25
(deg)
Freq
uenc
y (G
Hz)
0 50 100 15010
15
20
25
30
(deg)
Freq
uenc
y (G
Hz)
0 50 100 150 20012
14
16
18
20
22
24
26
28
(deg)
Freq
uenc
y (G
Hz)
Parameters First Cell Mid Cell Last Cell
a (mm) 4.3 3.35 2.4
L (mm) 10.4145 10.4145 10.4145
t (mm) 4 3.25 2.5
eps 2 2 2
b (mm) 12.696 12.086 11.641
Delta (mm) - 0.61 1.055
Elip 0.1 0.1 0.1
Rounding (mm) 1 1 1
WGW (mm) 6 6 6
WGH (mm) 5 5 5
SlotW (mm) 2.81 2.81 2.81
SlotH (mm) 1 1.61 2.055
InSlot (mm) 2 2 2
Htot (mm) 16.696 16.696 16.696
Hs/Ea (mA/V) 4.951 4.082 -
Es/Ea - 1.681 1.619
fsyn (GHz) [email protected]
Ksyn (V/pC/mm/m) 32.48 36.926 54.594
Av. Cross (MHz) 609 673 761
Vg (%c) 1.933 0.877 0.281
R/Q (k/m) 9.202 11.776 14.857
Mid Cell
Last Cell
First Cell
5pi/6
815 20 25 30 35 40 45
0
5
10
x 104
freq (GHz)
Abs
(Zx) (
/[
mm
m])
10 20 30 40 50-5
0
5
10
15x 10
4
freq (GHz)
Rea
l(Z x) (
/[
mm
m])
10 20 30 40 50-1
-0.5
0
0.5
1x 10
5
freq (GHz)
Imag
(Zx) (
/[
mm
m])
0 2 4 6 8 1010
0
101
102
s (m)
Wak
e (V
/[pC
mm
m])
<Qdip>=184
<Qdip>=495
Q=1438 (not yet saturated)
80 100 120 140 160 18014
15
16
17
18
19
(deg)
Freq
uenc
y (G
Hz)
Last Cell
5pi/6
Linear tapering
9
First Dipole Wake
0 2 4 6 8 1010
0
101
102
s (m)
Wak
e (V
/[pC
mm
m])
GdfidL WakeWake limitFirst Dipole Wake
0 0.2 0.4 0.6 0.8 110
0
101
102
s (m)
Wak
e (V
/[pC
mm
m])
GdfidL WakeWake limitFirst Dipole Wake
<Qdip>=382
dipole kick=61 V/pc mm m
Even if we get rid of the “higher” higher order modes, we are not able to efficiently damp first trailing bunches staying this detuning (~2.2GHz) and this damping (<Q>~382)
Linear tapering
10
Change Manifold WidthIf I change WGW: Dipole distribution stays the same but Manifold mode distribution will become higher and will “squash” against dipoles. This will move back the avoided crossing region. Drawback is a reduction of avoided crossing and a slight reduction of the fsyn of the cell.
fsyn (GHz) [email protected]
Av. Cross (MHz) 576
0 50 100 15015
16
17
18
19
20
(deg)
Freq
uenc
y (G
Hz)
Light Line
Manifold
Dipole
WGW=5mm
80 100 120 140 160 18014
15
16
17
18
19
(deg)
Freq
uenc
y (G
Hz)
WGW=6mm
0 50 100 15015
16
17
18
19
20
(deg)
Freq
uenc
y (G
Hz)
But…
First Cell, WGW=5mm
11
0 50 100 150
15
20
25
(deg)
Freq
uenc
y (G
Hz)
0 50 100 150
16
18
20
22
24
26
28
(deg)
Freq
uenc
y (G
Hz)
Parameters First Cell Mid Cell Last Cell
a (mm) 4.3 3.35 2.4
L (mm) 10.4145 10.4145 10.4145
t (mm) 4 3.25 2.5
eps 2 2 2
b (mm) 12.696 12.088 11.643
Delta (mm) - 0.608 1.053
Elip 0.1 0.1 0.1
Rounding (mm) 1 1 1
WGW (mm) 6 5.5 5
WGH (mm) 5 5 5
SlotW (mm) 2.81 2.81 2.81
SlotH (mm) 1 1.608 2.053
InSlot (mm) 2 2 2
Htot (mm) 16.696 16.696 16.696
Last Cell
First Cell
Tapered Manifold Width
1215 20 25 30 35 400
5
10
x 104
freq (GHz)
Abs
(Zx) (
/[m
m m
])
10 20 30 40 50-5
0
5
10
15x 10
4
freq (GHz)
Real
(Zx) (
/[m
m m
])
10 20 30 40 50-1
-0.5
0
0.5
1x 10
5
freq (GHz)
Imag
(Zx) (
/[m
m m
])
16 17 18 19 20 21 22
0
1
2
3x 10
4
freq (GHz)
Abs
(Zx) (
/[m
m m
])
10 20 30 40 50-5
0
5
10
15x 10
4
freq (GHz)
Real
(Zx) (
/[m
m m
])
10 20 30 40 50-1
-0.5
0
0.5
1x 10
5
freq (GHz)
Imag
(Zx) (
/[m
m m
])24.7 24.8 24.9 25 25.1 25.2 25.3 25.4 25.5
0
2
4
6
8
10
x 104
freq (GHz)
Abs
(Zx) (
/[
mm
m])
10 20 30 40 50-5
0
5
10
15x 10
4
freq (GHz)
Rea
l(Z x) (
/[
mm
m])
10 20 30 40 50-1
-0.5
0
0.5
1x 10
5
freq (GHz)
Imag
(Zx) (
/[
mm
m])
0 2 4 6 8 1010
0
101
102
s (m)
Wak
e (V
/[pC
mm
m])
Linear tapering
13
0 2 4 6 8 1010
0
101
102
s (m)
Wak
e (V
/[pC
mm
m])
GdfidLWake LimitOnly 1st band
0 2 4 6 8 1010
0
101
102
s (m)
Wak
e (V
/[pC
mm
m])
GdfidL WakeWake limitFirst Dipole Wake
Previous wake
Linear tapering
14
10 15 20 25 30 35 40 45 500
1
2
3x 10
4
freq (GHz)
Abs
(Zx) (
/[m
m m
])
0 20 40 60-1
0
1
2
3x 10
4
freq (GHz)
Rea
l(Z x) (
/[
mm
m])
0 20 40 60-2
-1
0
1
2x 10
4
freq (GHz)
Imag
(Zx) (
/[m
m m
])
0 0.2 0.4 0.6 0.8 110
0
101
102
s (m)
Wak
e (V
/[pC
mm
m])
1 1.2 1.4 1.6 1.8 210
0
101
102
s (m)
Wak
e (V
/[pC
mm
m])
2 2.2 2.4 2.6 2.8 310
0
101
102
s (m)
Wak
e (V
/[pC
mm
m])
3 3.5 4 4.5 510
0
101
102
s (m)
Wak
e (V
/[pC
mm
m])
10 15 20 25 30 35 40 45 500
2000
4000
6000
8000
10000
freq (GHz)
Abs
(Zx) (
/[m
m m
])
10 20 30 40 50-1
-0.5
0
0.5
1x 10
4
freq (GHz)
Rea
l(Z x) (
/[
mm
m])
10 20 30 40 50-10000
-5000
0
5000
freq (GHz)
Imag
(Zx) (
/[m
m m
])
10 20 30 40 500
2000
4000
freq (GHz)
Abs
(Zx) (
/[
mm
m])
0 20 40 60-4000
-2000
0
2000
4000
freq (GHz)
Real
(Zx) (
/[m
m m
])
0 20 40 60-4000
-2000
0
2000
4000
freq (GHz)
Imag
(Zx) (
/[m
m m
])
10 15 20 25 30 35 40 45 500
1
2
3
4x 10
4
freq (GHz)A
bs(Z
x) (
/[mm
m])
10 20 30 40 50-4
-2
0
2
4x 10
4
freq (GHz)
Rea
l(Z x) (
/[
mm
m])
10 20 30 40 50-2
0
2
4x 10
4
freq (GHz)Im
ag(Z
x) (
/[m
m m
])
1524 24.5 25 25.5 26 26.5 27 27.5 28
0
5
10
x 104
freq (GHz)
Abs
(Zx) (
/[
mm
m])
24 26 280
2
4
6
8
10x 10
4
freq (GHz)
Rea
l(Z x) (
/[
mm
m])
25 26 27
-5
0
5
x 104
freq (GHz)
Imag
(Zx) (
/[
mm
m])
1st Cell
E-Field@27GHz-7th Band
15 20 25 30 35 40 45 500
5
10x 10
5
freq (GHz)
Abs
(Zx) (
/[
mm
m])
20 30 40 50-5
0
5
10x 10
5
freq (GHz)
Rea
l(Z x) (
/[
mm
m])
20 30 40 50-1
-0.5
0
0.5
1x 10
6
freq (GHz)
Imag
(Zx) (
/[
mm
m])
0 50 100 150
15
20
25
(deg)
Freq
uenc
y (G
Hz)
1624 24.5 25 25.5 26 26.5 27 27.5
0.5
1
1.5
2
2.5x 10
5
freq (GHz)
Abs
(Zx) (
/[m
m m
])
20 30 40 50-5
0
5
10
15x 10
5
freq (GHz)
Rea
l(Z x) (
/[
mm
m])
20 30 40 50-1
-0.5
0
0.5
1x 10
6
freq (GHz)
Imag
(Zx) (
/[
mm
m])
0 50 100 15014
16
18
20
22
24
26
28
(deg)
Freq
uenc
y (G
Hz)
Mid Cell
[email protected] Band
15 20 25 30 35 40 45 500
5
10
15x 10
5
freq (GHz)
Abs
(Zx) (
/[
mm
m])
20 30 40 50-5
0
5
10
15x 10
5
freq (GHz)
Rea
l(Z x) (
/[
mm
m])
20 30 40 50-1
-0.5
0
0.5
1x 10
6
freq (GHz)
Imag
(Zx) (
/[
mm
m])
17
Last Cell
15 20 25 30 35 40 45 500
5
10
15x 10
5
freq (GHz)
Abs
(Zx) (
/[
mm
m])
20 30 40 50-5
0
5
10
15x 10
5
freq (GHz)
Rea
l(Z x) (
/[
mm
m])
20 30 40 50-1
-0.5
0
0.5
1x 10
6
freq (GHz)
Imag
(Zx) (
/[
mm
m])
18 20 22 24 260
5
10
x 105
freq (GHz)
Abs
(Zx) (
/[
mm
m])
20 30 40 50-5
0
5
10
15x 10
5
freq (GHz)
Rea
l(Z x) (
/[
mm
m])
20 30 40 50-1
-0.5
0
0.5
1x 10
6
freq (GHz)
Imag
(Zx) (
/[
mm
m])
0 50 100 150
16
18
20
22
24
26
28
(deg)
Freq
uenc
y (G
Hz)
[email protected] Band
18
Brillouin Diagram–EField
1st Band 5th Band
fsyn (GHz) [email protected] [email protected]
Ksyn (V/pC) (r=1mm) 0.05005 0.038333
Dangerous 5th BandLast Cell
0 50 100 15021
22
23
24
25
26
27
28
(deg)
Freq
uenc
y (G
Hz)
1st CellCoupling
5th Band
6th Band
7th Band
0 50 100 15021
22
23
24
25
26
27
28
(deg)
Freq
uenc
y (G
Hz)
Mid Cell
Hybrid
5th Band
6th Band
7th Band
Last Cell
0 50 100 15021
22
23
24
25
26
27
28
(deg)
Freq
uenc
y (G
Hz)
No Coupling
5th Band
6th Band
7th Band
19
Different cell geometries
18 19 20 21 22 23 24 250
5
10
15
x 105
freq (GHz)
Abs
(Zx) (
/[
mm
m])
10 20 30 40 50-5
0
5
10
15
20x 10
5
freq (GHz)
Rea
l(Z x) (
/[
mm
m])
10 20 30 40 50-2
-1
0
1
2x 10
6
freq (GHz)Im
ag(Z
x) (
/[m
m m
])
With SlotOriginal w/o Slot
17 18 19 20 21 22 23 24 250
5
10
15
x 105
freq (GHz)
Abs
(Zx) (
/[m
m m
])
10 20 30 40 50-5
0
5
10
15
20x 10
5
freq (GHz)
Real
(Zx) (
/[m
m m
])
10 20 30 40 50-2
-1
0
1
2x 10
6
freq (GHz)
Imag
(Zx) (
/[m
m m
])
data1data2
SlotOriginal w/o Slot
17 18 19 20 21 22 23 24 250
5
10
x 105
freq (GHz)
Abs
(Zx) (
/[
mm
m])
10 20 30 40 50-5
0
5
10
15x 10
5
freq (GHz)
Rea
l(Z x) (
/[
mm
m])
10 20 30 40 50-1
-0.5
0
0.5
1x 10
6
freq (GHz)
Imag
(Zx) (
/[
mm
m])
Slot WiderOriginal Slot
3.2mm
20
Conclusions• 5/9 (100 phase advance) structure exhibits, as expected, higher kicks
than 2/3 without any improvement in bandwidth (only 30MHz!)• 5/6:
– Pulse temperature rise limits the aperture of first iris to be lower than 4.3mm– This implies that in order to have a reasonable bandwidth last iris aperture must
be well below 3mm– Iris aperture lower than 3mm exhibits enhancement in the kicks of 5th-7th band– This enhancement is difficult to cure– From this analysis it comes out that:
1. With <Eacc>=100MV/m it looks very difficult to meet at the same time both CLIC beam dynamics (long range wake) and RF constraints
2. For CLIC_Zero with <Eacc>=80MV/m there could be some margin
• Nevertheless, CLIC_DDS_A prototype is (almost) ready to be tested: breakdown measurements will be crucial for DDS
• Started to apply DDS design to other facilities (ELI) and the results are very promising
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