1 Heinz-Dieter Nuhn [email protected] 1 Undulator Plans June 2009 FAC Undulator Commissioning...
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Transcript of 1 Heinz-Dieter Nuhn [email protected] 1 Undulator Plans June 2009 FAC Undulator Commissioning...
1 Heinz-Dieter [email protected]
1Undulator PlansJune 2009 FAC
Undulator Commissioning
Heinz-Dieter Nuhn – LCLS Undulator Group LeaderJune 8, 2009
3 Heinz-Dieter [email protected]
3Undulator PlansJune 2009 FAC
Segment Installation Schedule
Undulator Segments are being installed in the tunnel as they finish tuning
1/25/2009 – 3/2/2009 (U25 (SN16) Test installation)
3/3-24/2009 U13 – U33
4/22/2009 U09 – U12
5/13/2009 U06 – U08
6/3/2009 U04 and U05
6/3/2009 Removed U33 for damage check.
6/17/2009 U02, U03, and U33 installation planned.
Three plus one more undulators are to be installed
Regular Undulator Rotation Program will start after temperature calibration procedure
Undulator Segments are being installed in the tunnel as they finish tuning
1/25/2009 – 3/2/2009 (U25 (SN16) Test installation)
3/3-24/2009 U13 – U33
4/22/2009 U09 – U12
5/13/2009 U06 – U08
6/3/2009 U04 and U05
6/3/2009 Removed U33 for damage check.
6/17/2009 U02, U03, and U33 installation planned.
Three plus one more undulators are to be installed
Regular Undulator Rotation Program will start after temperature calibration procedure
4 Heinz-Dieter [email protected]
4Undulator PlansJune 2009 FAC
Undulator Beam Operation Highlights
December 13, 2008 First electron beam through undulator vacuum chamber.
No extra steering corrections necessary to get 100% transmission to main dump.
Pre-beam girder alignment was sufficient.
April 10, 2009 First electron beam through undulator segments.
Detected FEL beam after 105 minutes, CCD saturation 20 minutes later.
December 13, 2008 First electron beam through undulator vacuum chamber.
No extra steering corrections necessary to get 100% transmission to main dump.
Pre-beam girder alignment was sufficient.
April 10, 2009 First electron beam through undulator segments.
Detected FEL beam after 105 minutes, CCD saturation 20 minutes later.
5 Heinz-Dieter [email protected]
5Undulator PlansJune 2009 FAC
Preset Girder Positions for First Beam
• The girders were moved in x and y direction before the first beam was sent through the undulator, mostly to align the beam pipes and the quadrupoles as close to a straight line as possible but also to use the off-axis quadrupole fields to compensate for the earth magnetic field. Both corrections were based on measurements provided by the Metrology group.
• The first beam shot did not need any alignment correction to pass through the undulator beam pipe (remember a 130-m-long soda straw) to the main dump. The maximum orbit error was only about 1 mm. The plot is from J. Welch's girderPositionPlotGui and shows schematically the position by which each of the girders was displaced.
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6Undulator PlansJune 2009 FAC
Checking Undulator K Using YAG Luminescence*
10 or 11 undulators IN, Ipk = 500 A, LH = 200 uJFirst and third harmonic of spontaneous radiation as background
3rd hamrmonic ofSpontaneous
UndulatorRadiation on YAG
Crystal
Ee = 11.1 GeV
Ee = 11.3 GeV
Ee = 11.5 GeV
Ee = 11.7 GeV
Ee = 11.9 GeV
SpontaneousRadiation from
Dump Bend
Yttrium K Edge at 17.038 keVequals 3rd harmonic of undulator
radiation at 11.286 GeV
*by J. Welch and J. Frisch
Kmax =3.4256
Kmin =3.3532
Kavg =3.4616
Expected Kund = 3.4926±0.0005
More precise bracketing gave Kavg =3.4932±0.0045 (1.7 ×10-4 from expected value)
7 Heinz-Dieter [email protected]
7Undulator PlansJune 2009 FAC
YAG Screen Image of First Lasing
10 or 11 undulators IN, Ipk = 500 A, LH = 200 uJFirst and third harmonic of spontaneous radiation as background
FIRST LCLS FEL
LIGHT
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8Undulator PlansJune 2009 FAC
Undulator Characterization: 1st Field Integral U09
Beam Based Measurements
Horizontal (I1X) and vertical (I1Y) first field integrals measured by fitting a kick to the difference trajectory as function of undulator displacement
Reference Point
MMF Measurement
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9Undulator PlansJune 2009 FAC
Measurement of 1st Field Integral U11
Beam Based Measurements
Reference Point
MMF Measurement
The beam-based measurement relies on the RF cavity BPMS to achieve a 20 nrad measurement resolution of the kick angle inside the undulator
10 Heinz-Dieter [email protected]
10Undulator PlansJune 2009 FAC
Alignment Tolerance Verification
Random misalignment with flat distribution of widh ±a => rms distribution a/sqrt(3)
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11Undulator PlansJune 2009 FAC
Simulated: Horizontal Module Offset
Horizontal Model Offset (Gauss Fit)
Location Fit rms Unit
090 m 0782 µm
130 m 1121 µm
Average 0952 µm
Simulation and fit results of Horizontal Module Offset analysis. The larger amplitude data occur at the 130-m-point, the smaller amplitude data at the 90-m-point.
S. Reiche Simulations 2006S. Reiche Simulations 2006
BudgetTolerance
90 m
130 m
Simulated Saturation occurred at 90 m
Actual Simulation occurred at 68 m
Correction factor sqrt (90/68) = 1.15
This brings average to 1.10 mm
Simulated Saturation occurred at 90 m
Actual Simulation occurred at 68 m
Correction factor sqrt (90/68) = 1.15
This brings average to 1.10 mm
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12Undulator PlansJune 2009 FAC
LCLS Tolerance Budget
Error Source i fi i fi Units
@ 130 m (24.2% red.)
Hor/Ver Optics Mismatch (-1)0.5 0.71 0.452 0.32
Hor/Ver Transverse Beam Offset 30 0.176 3.7 µm
Module Detuning K/K 0.060 0.400 0.024 %
Module Offset in x 1121 0.125 140 µm
Module Offset in y 268 0.298 80 µm
Quadrupole Gradient Error 8.8 0.029 0.25 %
Transverse Quadrupole Offset 4.7 0.214 1.0 µm
Break Length Error 20.3 0.049 1.0 mm
< 1.10.64</0<1.56
< 1.10.64</0<1.56
21
2
0
ifPe
P
21
2
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Tolerance Budget ComponentsTolerance Budget Components
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13Undulator PlansJune 2009 FAC
Girder Stability : Position / Temperature
Temperature fluctuations, girder deformation, and ground motion cause changes in
Undulator strength, which depends on Temperature
Beam trajectory
Quadrupole position instability, which causes Changes to the electron beam trajectory (phase errors)
Good News: Observed stability of girder positions and temperatures is better than expected.
Temperature fluctuations, girder deformation, and ground motion cause changes in
Undulator strength, which depends on Temperature
Beam trajectory
Quadrupole position instability, which causes Changes to the electron beam trajectory (phase errors)
Good News: Observed stability of girder positions and temperatures is better than expected.
14 Heinz-Dieter [email protected]
14Undulator PlansJune 2009 FAC
Girder Stability During 2008 Winter Break
RMS Position Change < 1 µm
Alignment Diagnostics System (ADS)Alignment Diagnostics System (ADS)
Measurements show how much the girderposiiton deviatation from a straight line changed over the period of one week duringlab closure.
Measurements show how much the girderposiiton deviatation from a straight line changed over the period of one week duringlab closure.
15 Heinz-Dieter [email protected]
15Undulator PlansJune 2009 FAC
Girder 13 Stability During 19h Operation
200 nm
Alignment Diagnostics System (ADS)Alignment Diagnostics System (ADS)
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16Undulator PlansJune 2009 FAC
Girder 15 Movement (18 h) During ROD (11 h)
>1 µm
Mechanical Hysteresis
Alignment Diagnostics System (ADS)Alignment Diagnostics System (ADS)
17 Heinz-Dieter [email protected]
17Undulator PlansJune 2009 FAC
Temperature Recording of Girder 16
REPAIR OPPORTUNITY DAY (ROD)SHUT DOWN (UND INSTALLATION)
HVAC SETPOINT ADJUSTMENT
50 mK
18 Heinz-Dieter [email protected]
18Undulator PlansJune 2009 FAC
Temperature at all Girders
Mounted to UndulatorOn Girder
Downstream U23
Center U23
Upstream U23
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19Undulator PlansJune 2009 FAC
K is Adjusted for Temperature Deviations
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20Undulator PlansJune 2009 FAC
Use of (T-)Corrected K Values
K ADJUSTMENT RANGETEMPERATURE CORRECTED K
TAPER REQUIREMENT
21 Heinz-Dieter [email protected]
21Undulator PlansJune 2009 FAC
Radiation Control and Monitoring
Undulator radiation damage is greatly reduced through Machine Protection System (MPS) hardware interlocks that inhibit beam to the undulator hall when
PEP/ANL type BLM signals are above threshold Beam loss fiber signals are above threshold Horizontal and/or vertical trajectory is outside ±1mm Comparator toroids indicate beam loss. Any of the upstream profile monitors is inserted More than 1 BFW is inserted or a BFW is moving
A regular TLD monitoring program is in place(s. below)A regular undulator circulation program will start soon (s. below)
Undulator radiation damage is greatly reduced through Machine Protection System (MPS) hardware interlocks that inhibit beam to the undulator hall when
PEP/ANL type BLM signals are above threshold Beam loss fiber signals are above threshold Horizontal and/or vertical trajectory is outside ±1mm Comparator toroids indicate beam loss. Any of the upstream profile monitors is inserted More than 1 BFW is inserted or a BFW is moving
A regular TLD monitoring program is in place(s. below)A regular undulator circulation program will start soon (s. below)
22 Heinz-Dieter [email protected]
22Undulator PlansJune 2009 FAC
TLD Replacement Program
Thermo Luminescent Dosimeters (TLDs) are mounted inside the Undulator Hall and are regularly replaced and evaluated
Baseline 10/3/2008 – 12/9/2008 (10 TLDs) Startup 12/12/2008 – 12/17/2008 (12 TLDs) 1st Undulator 1/28/2009 – 2/4/2009 (15 TLDs) 1st Undulator 2/4/2009 – 2/11/2009 (14 TLDs) 1st Undulator 2/11/2009 – 2/18/2009 (18 TLDs) 1st Undulator 2/18/2009 – 3/2/2009 (48 TLDs) FEL Operation 3/24/2009 – 4/22/2009 (68 TLDs) FEL Operation 4/22/2009 – 5/6/2009 (125 TLDs) FEL Operation 5/6/2009 – 5/27/2009 (128 TLDs) FEL Operation 5/27/2009 – … (128 TLDs) FEL Operation …
Latest TLD placements include detection of neutrons and high energy gamma through use of moderators and W and Pb absorbers.TLD volume is expected to taper down after initial observation period.
Thermo Luminescent Dosimeters (TLDs) are mounted inside the Undulator Hall and are regularly replaced and evaluated
Baseline 10/3/2008 – 12/9/2008 (10 TLDs) Startup 12/12/2008 – 12/17/2008 (12 TLDs) 1st Undulator 1/28/2009 – 2/4/2009 (15 TLDs) 1st Undulator 2/4/2009 – 2/11/2009 (14 TLDs) 1st Undulator 2/11/2009 – 2/18/2009 (18 TLDs) 1st Undulator 2/18/2009 – 3/2/2009 (48 TLDs) FEL Operation 3/24/2009 – 4/22/2009 (68 TLDs) FEL Operation 4/22/2009 – 5/6/2009 (125 TLDs) FEL Operation 5/6/2009 – 5/27/2009 (128 TLDs) FEL Operation 5/27/2009 – … (128 TLDs) FEL Operation …
Latest TLD placements include detection of neutrons and high energy gamma through use of moderators and W and Pb absorbers.TLD volume is expected to taper down after initial observation period.
23 Heinz-Dieter [email protected]
23Undulator PlansJune 2009 FAC
TLD Readings at First Undulator
LOCATION WEEK 1 PHOTON [rad] WEEK 2 PHOTON [rad] WEEK 3 PHOTON [rad]
U25:ANL-BLM 0.081 0.106 0.051
U25: PEP-BLM 0.042 0.048 0.030
U25: Back +X 0.065 0.008 0.033
U25: Back +Y 0.012 0.071 0.064
U25: Back -X 0.039 0.026 0.029
U25: Back +Y 0.013 0.042 0.014
U25: Front +X 0.112 0.093 0.072
U25: Front +Y 0.217 0.105 0.110
U25: Front -X 0.046 0.055 0.025
U25: Front -Y 0.141 0.123 0.093
Recorder Photon Doses about 0.1 rad per weekRecorder Photon Doses about 0.1 rad per week
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24Undulator PlansJune 2009 FAC
SN16 Radiation Damage Test
HAS BEEN INSTALLED ON GIRDER 25 DURING BEAM OPERATION
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25Undulator PlansJune 2009 FAC
Dose During Initial X-Ray Operation
e-folding length 8.7 me-folding length 8.7 m
Increased TLD Readings are expected to be predominantly low energy synchrotron radiation, not to cause significant magnet damageIncreased TLD Readings are expected to be predominantly low energy synchrotron radiation, not to cause significant magnet damage
[rad
]
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26Undulator PlansJune 2009 FAC
Dose During Recent X-Ray Operation
e-folding length 8.7 me-folding length 8.7 m
Increased TLD Readings are expected to be predominantly low energy synchrotron radiation, not to cause significant magnet damageIncreased TLD Readings are expected to be predominantly low energy synchrotron radiation, not to cause significant magnet damage
neutron dose at end of undulator line about 100 mrad/week or lessneutron dose at end of undulator line about 100 mrad/week or less
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27Undulator PlansJune 2009 FAC
TLD Readings at End of Undulator Line
LOCATION Photon Dose over 3 weeks [rad]
Downstream U32 without / with 1.6 mm Pb wrap 0.52 / 1.84
Downstream U33 without / with 1.6 mm Pb wrap 1.38 / 6.37
Downstream (about 2.5 m) U33 without / with W 0.62 / 0.05
Downstream (about 2.5 m) U33 without / with Al 0.59 / 0.31
U33 Cam Motors CM2 / CM5 0.00 / 0.02
U33 Horizontal Slide Motor SL1 0.08
On top of RFBPM Chassis U31 / U32 0.04 / 0.31
Girder Motion Electronics Racks U25 / U29 / U33 0.03 / 0.01 / 0.01
WPM Electronics Racks U25 / U31 2.08 / .08
North Side of Tunnel opposite of U33 0.08
Sh
ield
ed
Sh
ield
ed
Ele
ctr
on
ics
Ele
ctr
on
ics
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28Undulator PlansJune 2009 FAC
SN20 Radiation Damage Test
HAS BEEN INSTALLED ON GIRDER 33 DURING FEL OPERATION
29 Heinz-Dieter [email protected]
29Undulator PlansJune 2009 FAC
Undulator Circulation Program
Undulators will be periodically removed from the Undulator Hall to be re-measured at the MMF to check for radiation damageA “test”-undulator was re-measured after several weeks of beam operation. No damage was found.First undulator that participated in FEL run was removed on June 3 and MMF testing has found it to be undamaged Depending on MMF availability, up to 2 undulators per month will be removed from the Undulator Hall for checkingAfter the undulators have been found undamaged they will be reinstalled onto the original girder
Undulators will be periodically removed from the Undulator Hall to be re-measured at the MMF to check for radiation damageA “test”-undulator was re-measured after several weeks of beam operation. No damage was found.First undulator that participated in FEL run was removed on June 3 and MMF testing has found it to be undamaged Depending on MMF availability, up to 2 undulators per month will be removed from the Undulator Hall for checkingAfter the undulators have been found undamaged they will be reinstalled onto the original girder
30 Heinz-Dieter [email protected]
30Undulator PlansJune 2009 FAC
Undulator tuning and installation close to completionInitial beam operation went extremely smoothly: no tweaking requiredTemperature and girder stability are well within toleranceBeam loss control and radiation monitoring is in placeHigh radiation levels at initial FEL operation are expected to be predominantly low energy photons that should not generate demagnetizationVery low dose levels measured at electronics componentsUndulator circulation program has started
Undulator tuning and installation close to completionInitial beam operation went extremely smoothly: no tweaking requiredTemperature and girder stability are well within toleranceBeam loss control and radiation monitoring is in placeHigh radiation levels at initial FEL operation are expected to be predominantly low energy photons that should not generate demagnetizationVery low dose levels measured at electronics componentsUndulator circulation program has started
Summary