1 Heinz-Dieter Nuhn nuhn@slac.stanford.edu 1 Undulator Plans June 2009 FAC Undulator Commissioning Heinz-Dieter Nuhn – LCLS Undulator Group Leader June.

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  • Slide 1
  • 1 Heinz-Dieter Nuhn nuhn@slac.stanford.edu 1 Undulator Plans June 2009 FAC Undulator Commissioning Heinz-Dieter Nuhn LCLS Undulator Group Leader June 8, 2009
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  • 2 Heinz-Dieter Nuhn nuhn@slac.stanford.edu 2 Undulator Plans June 2009 FAC 29 Undulators Installed
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  • 3 Heinz-Dieter Nuhn nuhn@slac.stanford.edu 3 Undulator Plans June 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
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  • 4 Heinz-Dieter Nuhn nuhn@slac.stanford.edu 4 Undulator Plans June 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.
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  • 5 Heinz-Dieter Nuhn nuhn@slac.stanford.edu 5 Undulator Plans June 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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  • 6 Heinz-Dieter Nuhn nuhn@slac.stanford.edu 6 Undulator Plans June 2009 FAC Checking Undulator K Using YAG Luminescence* 10 or 11 undulators IN, Ipk = 500 A, LH = 200 uJ First and third harmonic of spontaneous radiation as background 3 rd hamrmonic of Spontaneous Undulator Radiation on YAG Crystal E e = 11.1 GeV E e = 11.3 GeV E e = 11.5 GeV E e = 11.7 GeV E e = 11.9 GeV Spontaneous Radiation from Dump Bend Yttrium K Edge at 17.038 keV equals 3 rd 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 = 3.49260.0005 More precise bracketing gave Kavg =3.49320.0045 (1.7 10 -4 from expected value)
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  • 7 Heinz-Dieter Nuhn nuhn@slac.stanford.edu 7 Undulator Plans June 2009 FAC YAG Screen Image of First Lasing 10 or 11 undulators IN, Ipk = 500 A, LH = 200 uJ First and third harmonic of spontaneous radiation as background FIRST LCLS FEL LIGHT
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  • 8 Heinz-Dieter Nuhn nuhn@slac.stanford.edu 8 Undulator Plans June 2009 FAC Undulator Characterization: 1 st 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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  • 9 Heinz-Dieter Nuhn nuhn@slac.stanford.edu 9 Undulator Plans June 2009 FAC Measurement of 1 st 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
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  • 10 Heinz-Dieter Nuhn nuhn@slac.stanford.edu 10 Undulator Plans June 2009 FAC Alignment Tolerance Verification Random misalignment with flat distribution of widh a => rms distribution a/sqrt(3)
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  • 11 Heinz-Dieter Nuhn nuhn@slac.stanford.edu 11 Undulator Plans June 2009 FAC Simulated: Horizontal Module Offset Horizontal Model Offset (Gauss Fit) LocationFit rmsUnit 090 m0782m 130 m1121m Average0952m 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 2006 Budget Tolerance 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
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  • 12 Heinz-Dieter Nuhn nuhn@slac.stanford.edu 12 Undulator Plans June 2009 FAC LCLS Tolerance Budget Error Source ii fifi i f i Units @ 130 m(24.2% red.) Hor/Ver Optics Mismatch ( -1) 0.5 0.710.4520.32 Hor/Ver Transverse Beam Offset300.1763.7m Module Detuning K/K 0.0600.4000.024% Module Offset in x11210.125140m Module Offset in y2680.29880m Quadrupole Gradient Error8.80.0290.25% Transverse Quadrupole Offset4.70.2141.0m Break Length Error20.30.0491.0mm < 1.1 0.64< / 0
  • 16 Heinz-Dieter Nuhn nuhn@slac.stanford.edu 16 Undulator Plans June 2009 FAC Girder 15 Movement (18 h) During ROD (11 h) >1 m Mechanical Hysteresis Alignment Diagnostics System (ADS)
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  • 17 Heinz-Dieter Nuhn nuhn@slac.stanford.edu 17 Undulator Plans June 2009 FAC Temperature Recording of Girder 16 REPAIR OPPORTUNITY DAY (ROD) SHUT DOWN (UND INSTALLATION) HVAC SETPOINT ADJUSTMENT 50 mK
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  • 18 Heinz-Dieter Nuhn nuhn@slac.stanford.edu 18 Undulator Plans June 2009 FAC Temperature at all Girders Mounted to Undulator On Girder Downstream U23 Center U23 Upstream U23
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  • 19 Heinz-Dieter Nuhn nuhn@slac.stanford.edu 19 Undulator Plans June 2009 FAC K is Adjusted for Temperature Deviations
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  • 20 Heinz-Dieter Nuhn nuhn@slac.stanford.edu 20 Undulator Plans June 2009 FAC Use of (T-)Corrected K Values K ADJUSTMENT RANGE TEMPERATURE CORRECTED K TAPER REQUIREMENT
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  • 21 Heinz-Dieter Nuhn nuhn@slac.stanford.edu 21 Undulator Plans June 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)
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  • 22 Heinz-Dieter Nuhn nuhn@slac.stanford.edu 22 Undulator Plans June 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) 1 st Undulator 1/28/2009 2/4/2009 (15 TLDs) 1 st Undulator 2/4/2009 2/11/2009 (14 TLDs) 1 st Undulator 2/11/2009 2/18/2009 (18 TLDs) 1 st 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) 1 st Undulator 1/28/2009 2/4/2009 (15 TLDs) 1 st Undulator 2/4/2009 2/11/2009 (14 TLDs) 1 st Undulator 2/11/2009 2/18/2009 (18 TLDs) 1 st 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.
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  • 23 Heinz-Dieter Nuhn nuhn@slac.stanford.edu 23 Undulator Plans June 2009 FAC TLD Readings at First Undulator LOCATIONWEEK 1 PHOTON [rad]WEEK 2 PHOTON [rad]WEEK 3 PHOTON [rad] U25:ANL-BLM0.0810.1060.051 U25: PEP-BLM0.0420.0480.030 U25: Back +X0.0650.0080.033 U25: Back +Y0.0120.0710.064 U25: Back -X0.0390.0260.029 U25: Back +Y0.0130.0420.014 U25: Front +X0.1120.0930.072 U25: Front +Y0.2170.1050.110 U25: Front -X0.0460.0550.025 U25: Front -Y0.1410.1230.093 Recorder Photon Doses about 0.1 rad per week
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  • 24 Heinz-Dieter Nuhn nuhn@slac.stanford.edu 24 Undulator Plans June 2009 FAC SN16 Radiation Damage Test HAS BEEN INSTALLED ON GIRDER 25 DURING BEAM OPERATION
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  • 25 Heinz-Dieter Nuhn nuhn@slac.stanford.edu 25 Undulator Plans June 2009 FAC Dose During Initial X-Ray Operation e-folding length 8.7 m Increased TLD Readings are expected to be predominantly low energy synchrotron radiation, not to cause significant magnet damage [rad]
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  • 26 Heinz-Dieter Nuhn nuhn@slac.stanford.edu 26 Undulator Plans June 2009 FAC Dose During Recent X-Ray Operation e-folding length 8.7 m Increased 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 less
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  • 27 Heinz-Dieter Nuhn nuhn@slac.stanford.edu 27 Undulator Plans June 2009 FAC TLD Readings at End of Undulator Line LOCATIONPhoton Dose over 3 weeks [rad] Downstream U32 without / with 1.6 mm Pb wrap0.52 / 1.84 Downstream U33 without / with 1.6 mm Pb wrap1.38 / 6.37 Downstream (about 2.5 m) U33 without / with W0.62 / 0.05 Downstream (about 2.5 m) U33 without / with Al0.59 / 0.31 U33 Cam Motors CM2 / CM50.00 / 0.02 U33 Horizontal Slide Motor SL10.08 On top of RFBPM Chassis U31 / U320.04 / 0.31 Girder Motion Electronics Racks U25 / U29 / U330.03 / 0.01 / 0.01 WPM Electronics Racks U25 / U312.08 /.08 North Side of Tunnel opposite of U330.08 Shielded Electronics
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  • 28 Heinz-Dieter Nuhn nuhn@slac.stanford.edu 28 Undulator Plans June 2009 FAC SN20 Radiation Damage Test HAS BEEN INSTALLED ON GIRDER 33 DURING FEL OPERATION
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  • 29 Heinz-Dieter Nuhn nuhn@slac.stanford.edu 29 Undulator Plans June 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 damage A 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 checking After 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 damage A 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 checking After the undulators have been found undamaged they will be reinstalled onto the original girder
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  • 30 Heinz-Dieter Nuhn nuhn@slac.stanford.edu 30 Undulator Plans June 2009 FAC Undulator tuning and installation close to completion Initial beam operation went extremely smoothly: no tweaking required Temperature and girder stability are well within tolerance Beam loss control and radiation monitoring is in place High radiation levels at initial FEL operation are expected to be predominantly low energy photons that should not generate demagnetization Very low dose levels measured at electronics components Undulator circulation program has started Undulator tuning and installation close to completion Initial beam operation went extremely smoothly: no tweaking required Temperature and girder stability are well within tolerance Beam loss control and radiation monitoring is in place High radiation levels at initial FEL operation are expected to be predominantly low energy photons that should not generate demagnetization Very low dose levels measured at electronics components Undulator circulation program has started Summary
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  • 31 Heinz-Dieter Nuhn nuhn@slac.stanford.edu 31 Undulator Plans June 2009 FAC End of Presentation

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