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XFELThe EuropeanX-Ray Laser Project X-Ray Free-Electron Laser
Lutz Lilje, DESY, TILC08
Tests with the Fast Frequency Tuners in the Saclay-I design
Lutz Lilje
DESY
Lutz Lilje, DESY, TILC08يح
XFELThe EuropeanX-Ray Laser Project X-Ray Free-Electron Laser
Acknowledgements
– Thanks for– … the participation and support in the
experiments• R. Paparella, K. Przygoda
– … to many people supporting these experiments
• C. Albrecht, O. Keller, C. Müller, T. Fröhlich, R. Lange, T. Bruns, W. Koprek, W. Jalmuzna, A. Brandt, D. Kostin
Lutz Lilje, DESY, TILC08يح
XFELThe EuropeanX-Ray Laser Project X-Ray Free-Electron Laser
Motivation
– It is clear that the current version of this tuner does not fit mechanically.
– Nonetheless, the tuner tests ILC concepts• Standard TESLA cavity design (and short ILC design)
– Stiffening concept
• Motor– Cold location
• Piezo– Cold location
Lutz Lilje, DESY, TILC08يح
XFELThe EuropeanX-Ray Laser Project X-Ray Free-Electron Laser
Overview
– Tuner system• Saclay design with added piezo tuner
– Measurements on Modules• Classical Pretuning of the cavity
– Cavity pushes back on the tuner» Difficult to adjust pre-load on the cavity
• Double-Piezo fixture– M6, (M8)
• Single-Piezo fixture– M5, M7
– CHECHIA Measurements• Reversed Pretuning of the cavities
– Cavity pulls on tuner
Lutz Lilje, DESY, TILC08يح
XFELThe EuropeanX-Ray Laser Project X-Ray Free-Electron Laser
Tuner Setup
– Current design in use at FLASH• Design by CEA
• Fast piezo detuning introduced not from beginning
• Is the solution for XFEL so far
Design by M. Maurier and P. Leconte based of the MACSE tuner design (CEA
Saclay)
Lscrew
LarmsLcavity
Lutz Lilje, DESY, TILC08يح
XFELThe EuropeanX-Ray Laser Project X-Ray Free-Electron Laser
Tuner System Features
– Well-known– Piezo integration not straight-forward
• Piezo fixture stiff enough for pre-detuning of roughly +300 KHz
– Beyond this piezo operation cannot be guaranteed
– Therefore reverse pre-tuning (-200 kHz) of cavities has ben tried in CHECHIA tests
• Successful
– M8 is fully equipped with this type of piezos• Test this year
Lutz Lilje, DESY, TILC08يح
XFELThe EuropeanX-Ray Laser Project X-Ray Free-Electron Laser
Module 6 Double-Piezo Tests
– Initial demonstration for each cavity• Measure detuning• Compensate detuning individually, one after the other
– Classical compensation
– ´Second oscillation´ compensation
– No RF feedback
• In addition– Work on piezo diagnostics: Impedance measurement
– Measure transfer functions from one piezo to another
– Demonstrate compensation on full module for all cavities simultaneously
• With RF feedback
Lutz Lilje, DESY, TILC08يح
XFELThe EuropeanX-Ray Laser Project X-Ray Free-Electron Laser
Lorentz Force Detunings in Module 6
0
100
200
300
400
500
600
700
800
0 5 10 15 20 25 30 35 40
Eacc[MV/m]
Det
un
ing
ove
r F
lat-
To
p [
Hz]
C1C2C3C4C5C6C7C8
Lutz Lilje, DESY, TILC08يح
XFELThe EuropeanX-Ray Laser Project X-Ray Free-Electron Laser
Example: Cavity 3
Lorentz Force Detuning
0
100
200
300
400
500
600
700
800
0 5 10 15 20 25 30 35 40
Cavity Gradient [MV/m]
Lore
ntz
Forc
e de
tuni
ng [H
z]
Lutz Lilje, DESY, TILC08يح
XFELThe EuropeanX-Ray Laser Project X-Ray Free-Electron Laser
Cavity 3: Gradient
35 MV/m
Lutz Lilje, DESY, TILC08يح
XFELThe EuropeanX-Ray Laser Project X-Ray Free-Electron Laser
Cavity 3: Phase
Lutz Lilje, DESY, TILC08يح
XFELThe EuropeanX-Ray Laser Project X-Ray Free-Electron Laser
Cavity 3: Detuning
Lutz Lilje, DESY, TILC08يح
XFELThe EuropeanX-Ray Laser Project X-Ray Free-Electron Laser
Compensated Detuning per Cavity
Maximum Lorentz Force detuning compensation results
0
100
200
300
400
500
600
700
cav 1 - 35 MV/m cav 2 - 31 MV/m cav 3 - 35 MV/m cav 4 - 33 MV/m cav 6 - 20 MV/m cav 7 - 30 MV/m cav 8 - 23 MV/m
Det
unin
g ov
er th
e fla
t-top
[Hz]
Piezo OFF
Piezo ON
Lutz Lilje, DESY, TILC08يح
XFELThe EuropeanX-Ray Laser Project X-Ray Free-Electron Laser
Voltage on Piezo Needed for CompensationCompensated Detuning vs. Applied Piezo Voltage
half-sine pulse, 2.5 ms width and 0.6 to 0.64 ms advance from RF pulse
y = 7,594x
R2 = 0,98
0
100
200
300
400
500
600
700
0 10 20 30 40 50 60 70 80 90 100
Piezo Voltage [V]
Com
pens
ated
det
unin
g [H
z]
CAV 3
Linear (CAV 3)
– Piezo Voltages within margin• maximum PI piezo voltage of 120 V at room temperature• Could also use bipolar operation, but not needed
Lutz Lilje, DESY, TILC08يح
XFELThe EuropeanX-Ray Laser Project X-Ray Free-Electron Laser
Compensated Detuning vs. Delay to RF@25 MV/m
Normalized detuning over the flat-top for vs. piezo pulse delay
0,0
0,2
0,4
0,6
0,8
1,0
1,2
1,4
1,6
1,8
2,0
-7 -6 -5 -4 -3 -2 -1 0 1 2Piezo pulse start time [ms]
No
rma
lize
d a
mp
litu
de
Delay analysison cavity 1
Delay analysison cavity 2
Delay analysison cavity 6
Delay analysison cavity 7
2nd osc.compensationresults1st osc.compensationresults
RF pulse
Lutz Lilje, DESY, TILC08يح
XFELThe EuropeanX-Ray Laser Project X-Ray Free-Electron Laser
Pre-Detuning Change Due to Piezo Pulse Delay when using the ‚second oscillation‘
– Can change the cavity pre-detuning of the cavity by changing the Piezo delay to use the ‘second oscillation‘ in the order of 200Hz
• Less motor usage, increase lifetime• Correponds to He drifts of a few mbar
Cavity 4
Lutz Lilje, DESY, TILC08يح
XFELThe EuropeanX-Ray Laser Project X-Ray Free-Electron Laser
Full Module Tests
– Three modules tested with piezos• M5, M6, M7
– At least one module will be done this year• M8• M3 repair (after crash test) to be decided
– Simultaneous operation of several piezos with the same drive signal possible
• Only 2 function generators (FG) available• E.g. 4 cavities on one FG with amplifier and 2 cavities on the other FG
with second amplifier for M6
Lutz Lilje, DESY, TILC08يح
XFELThe EuropeanX-Ray Laser Project X-Ray Free-Electron Laser
0 200 400 600 800 1000 1200 14005
5.1
5.2
5.3
5.4
5.5
5.6
5.7
5.8
5.9
6
Time [us]
Am
plitu
de [A
.U.]
Vector Sum of Module 6 with and without piezo active compensationRF feedback ON, same control-loop-gain setting
0 200 400 600 800 1000 1200 140018
18.5
19
19.5
20
20.5
21
21.5
22
Time [us]
Pha
se [d
eg]
Piezo compensation OFFPiezo compensation ON
Operation of Full module – Vector-Sum
Lutz Lilje, DESY, TILC08يح
XFELThe EuropeanX-Ray Laser Project X-Ray Free-Electron Laser
Operation of Full Module – Forward Power
0 500 1000 1500 20000
50
100
150
200
250
300
350
Time [us]
For
war
d po
wer
am
p. [
kW]
0 500 1000 1500 20000
50
100
150
200
250
300
350
Time [us]
For
war
d po
wer
am
p. [
kW]
0 500 1000 1500 20000
50
100
150
200
250
300
350
Time [us]
For
war
d po
wer
am
p. [
kW]
RF feedback switched ON on module 6 in CMTB. Collection of all amplitude of forward power signals with and without piezo active compensation
0 500 1000 1500 20000
50
100
150
200
250
300
350
Time [us]
For
war
d po
wer
am
p. [
kW]
0 500 1000 1500 20000
20
40
60
80
100
120
140
Time [us]
For
war
d po
wer
am
p. [
kW]
0 500 1000 1500 20000
50
100
150
Time [us]
For
war
d po
wer
am
p. [
kW]
0 500 1000 1500 20000
50
100
150
200
250
Time [us]
For
war
d po
wer
am
p. [
kW]
0 500 1000 1500 20000
50
100
150
200
Time [us]
For
war
d po
wer
am
p. [
kW]
Piezo compensation OFF
Piezo compensation ON
Lutz Lilje, DESY, TILC08يح
XFELThe EuropeanX-Ray Laser Project X-Ray Free-Electron Laser
500 1000 1500 2000-400
-300
-200
-100
0
100
200
300
400
Time [us]
Det
unin
g [H
z]
500 1000 1500 2000-400
-300
-200
-100
0
100
200
300
400
Time [us]
Det
unin
g [H
z]
500 1000 1500 2000-400
-300
-200
-100
0
100
200
300
400
Time [us]
Det
unin
g [H
z]
Detuning of all cavities of Module 6 with and without piezo active compensation
500 1000 1500 2000-400
-300
-200
-100
0
100
200
300
400
Time [us]
Det
unin
g [H
z]
Cavity 1,2,3,4 : signal 1 - half sin 2.5 ms width, 60 V, 640 us advance
500 1000 1500 2000-400
-300
-200
-100
0
100
200
300
400
Time [us]
Det
unin
g [H
z]
500 1000 1500 2000-400
-300
-200
-100
0
100
200
300
400
Time [us]
Det
unin
g [H
z]
Cavity 5,6 : no signal - no active compensation
500 1000 1500 2000-400
-300
-200
-100
0
100
200
300
400
Time [us]
Det
unin
g [H
z]
500 1000 1500 2000-400
-300
-200
-100
0
100
200
300
400
Time [us]
Det
unin
g [H
z]
Cavity 7,8 : signal 2 - half sin 2.5 ms width, 64 V, 640 us advance
Lutz Lilje, DESY, TILC08يح
XFELThe EuropeanX-Ray Laser Project X-Ray Free-Electron Laser
M5: Piezos off
Lutz Lilje, DESY, TILC08يح
XFELThe EuropeanX-Ray Laser Project X-Ray Free-Electron Laser
M5: Piezos on
Lutz Lilje, DESY, TILC08يح
XFELThe EuropeanX-Ray Laser Project X-Ray Free-Electron Laser
Tests with New Pre-tuning
– E.g. Z107 at 35 MV/m
– Piezo settings• Simple pulse• Frequency: 400
Hz• Voltage: 2.4 V
(roughly 100 V)• Offset: -0.4• Advance to RF
signal:0.8511 ms
Lutz Lilje, DESY, TILC08يح
XFELThe EuropeanX-Ray Laser Project X-Ray Free-Electron Laser
Next for this type of tuner
– Industrialisation for XFEL• Drive units
– Full-drive units from Industry– This year
• Mechanics– Involvement of Mass-production companies– This year
– Series production in 2009
Lutz Lilje, DESY, TILC08يح
XFELThe EuropeanX-Ray Laser Project X-Ray Free-Electron Laser
Conclusion and Outlook
– Several aspects of relevance for ILC• Concept• Choice of active elements• Industrialization
– Piezo as actuators• Endurance operation in TTF will start this year
– Endurance tests in test stands have been done already– Successful compensation of detuning on full modules simultaneously
• TESLA cavities are stiff enough
– ´Second oscillation´ compensation could reduce number of steps on the motors as delay of Piezo could be used to compensate for small frequency drifts
• Relaxes reliability requirements on motors
– Industrialization of the full tuner system is on the way for XFEL