October 30, 2007 Heinz-Dieter Nuhn, SLAC / LCLS Undulator Commissioning Plans Nuhn@slac.stanford.edu 1 Undulator Commissioning Plans Heinz-Dieter Nuhn,

  • Published on
    19-Dec-2015

  • View
    212

  • Download
    0

Transcript

  • Slide 1
  • October 30, 2007 Heinz-Dieter Nuhn, SLAC / LCLS Undulator Commissioning Plans Nuhn@slac.stanford.edu 1 Undulator Commissioning Plans Heinz-Dieter Nuhn, SLAC / LCLS October 30, 2007 Getting the Undulator System Ready for Operation.
  • Slide 2
  • October 30, 2007 Heinz-Dieter Nuhn, SLAC / LCLS Undulator Commissioning Plans Nuhn@slac.stanford.edu 2 Getting Undulator System Ready for Operation Installation and Rough Alignment ADS Commissioning and Conventional Girder Alignment Pre-Beam Checkouts PPS Verification Commissioning with Beam Commissioning of Electron Beam Components Commissioning of X-Ray Beam Diagnostics Characterization of Spontaneous Radiation Generation and Characterization of FEL Radiation Transition to Operation Installation and Rough Alignment ADS Commissioning and Conventional Girder Alignment Pre-Beam Checkouts PPS Verification Commissioning with Beam Commissioning of Electron Beam Components Commissioning of X-Ray Beam Diagnostics Characterization of Spontaneous Radiation Generation and Characterization of FEL Radiation Transition to Operation
  • Slide 3
  • October 30, 2007 Heinz-Dieter Nuhn, SLAC / LCLS Undulator Commissioning Plans Nuhn@slac.stanford.edu 3 ADS Commissioning and Conventional Girder Alignment ADS (WPM & HLS) Commissioning ADS Control System Checkout Quadrupole Alignment to Straight Line (100 microns) Monitored with ADS Loose-End (BFW side of girder) Pre-Alignment Using Portable WPM/HLS ADS (WPM & HLS) Commissioning ADS Control System Checkout Quadrupole Alignment to Straight Line (100 microns) Monitored with ADS Loose-End (BFW side of girder) Pre-Alignment Using Portable WPM/HLS
  • Slide 4
  • October 30, 2007 Heinz-Dieter Nuhn, SLAC / LCLS Undulator Commissioning Plans Nuhn@slac.stanford.edu 4 Pre-Beam Checkouts HVAC System Checkout Control System Checkout Network Configuration of IOC's Timing System Communication with ADS Checkout Verification of individual Device Operation Magnet Power Supplies and Interlocks BPM Cable Checkout BPMs Beam Finder Wire Undulator Motion Control Checkout CAM Mover Motion Checkout Transverse Slide Motion Checkout Compound Motion Checkout Electro-Magnet Polarity Checkout Quadrupole Main Coils Polarity Checkouts Quadrupole Trim Coils Polarity Checkouts BFW System Checkout HVAC System Checkout Control System Checkout Network Configuration of IOC's Timing System Communication with ADS Checkout Verification of individual Device Operation Magnet Power Supplies and Interlocks BPM Cable Checkout BPMs Beam Finder Wire Undulator Motion Control Checkout CAM Mover Motion Checkout Transverse Slide Motion Checkout Compound Motion Checkout Electro-Magnet Polarity Checkout Quadrupole Main Coils Polarity Checkouts Quadrupole Trim Coils Polarity Checkouts BFW System Checkout
  • Slide 5
  • October 30, 2007 Heinz-Dieter Nuhn, SLAC / LCLS Undulator Commissioning Plans Nuhn@slac.stanford.edu 5 Getting Undulator System Ready for Operation Installation and Rough Alignment Conventional Girder Alignment Pre-Beam Checkouts PPS Verification Commissioning with Beam Electron Beam Commissioning Commissioning of X-Ray Beam Diagnostics Characterization of Spontaneous Radiation Generation and Characterization of FEL Radiation Transition to Operation Installation and Rough Alignment Conventional Girder Alignment Pre-Beam Checkouts PPS Verification Commissioning with Beam Electron Beam Commissioning Commissioning of X-Ray Beam Diagnostics Characterization of Spontaneous Radiation Generation and Characterization of FEL Radiation Transition to Operation
  • Slide 6
  • October 30, 2007 Heinz-Dieter Nuhn, SLAC / LCLS Undulator Commissioning Plans Nuhn@slac.stanford.edu 6 LCLS Commissioning Parameters (Inj/Lin Example) ParameterValueComments RF rate 30 Hz 30 Hz in linac (possible short-term 120 Hz linac rate in L0-BC1 for feedback tests, etc) - 120 Hz in gun for short time to verify full rate Beam rate 30 Hz 30 Hz e- beam as baseline possible 120-Hz tests in L0-BC1 for short term verification of feedback, etc Drive-laser rate 120 Hz 120-Hz all the times pulse-picker provides e rate as required above Bunch charge 200-500 pC 200-500 pC, depending on QE and diagnostics - short spans at 10 pC later in 07 we explore 1-nC Drive-laser pulse length 10 ps fwhm 10 ps FWHM startup with possibility of 6-ps at 0.2 nC later early laser tests may provide path to more convenient pulse-length changes Gun gradient 120 MV/m 120 MV/m, although 110 MV/m is adequate in 07 L0-b gradient 24 MV/m 24 MV/m in L0-b (not critical in 07)
  • Slide 7
  • October 30, 2007 Heinz-Dieter Nuhn, SLAC / LCLS Undulator Commissioning Plans Nuhn@slac.stanford.edu 7 Generic Staffing Plan Two 8-hour shifts per day of e- Two physicists per shift One controls person per shift At least one operator per shift assigned to LCLS One engineer on call and when required for early system tests One technician per shift (all 3) and one laser-physicist on call per shift Two 8-hour shifts per day of e- Two physicists per shift One controls person per shift At least one operator per shift assigned to LCLS One engineer on call and when required for early system tests One technician per shift (all 3) and one laser-physicist on call per shift
  • Slide 8
  • October 30, 2007 Heinz-Dieter Nuhn, SLAC / LCLS Undulator Commissioning Plans Nuhn@slac.stanford.edu 8 Electron Beam Commissioning to Tune-Up Dump Beam and Beam Stability Characterization Emittance Energy Spread Charge Energy Transverse and Longitudinal Profiles Energy Dependent Optics Tuning (Electron Beam Matching) Energy Dependent Electron Beam Steering (Launch Condition into Undulator System) RF-Cavity BPM Commissioning (2 RF-Cavity BPMs before Tune-Up Dump) Beam and Beam Stability Characterization Emittance Energy Spread Charge Energy Transverse and Longitudinal Profiles Energy Dependent Optics Tuning (Electron Beam Matching) Energy Dependent Electron Beam Steering (Launch Condition into Undulator System) RF-Cavity BPM Commissioning (2 RF-Cavity BPMs before Tune-Up Dump)
  • Slide 9
  • October 30, 2007 Heinz-Dieter Nuhn, SLAC / LCLS Undulator Commissioning Plans Nuhn@slac.stanford.edu 9 First Beam Through Undulator Vacuum System Conditions for First Beam: All Undulator Magnets Rolled-Out (Quads could initially be turned off, too) Single Shot Operation Send single electron bunch towards undulator Read and evaluate as much diagnostics as possible along undulator (such as BPMs, beam loss monitors, toroids) Identify and remove sources of beam loss Iterate Low Charge: 200 pC or less Diagnostics designed for micron-type resolution over 200-1000 pC range Resolution drops proportionally for out-of-range charges. Out-of-range resolution still sufficient for initial commissioning steps, which only requires resolution in the 100 micron range. Goal: Get beam through vacuum chamber with minimum losses. Reminder: Main Constraint is to Protect Undulator from Radiation Damage Conditions for First Beam: All Undulator Magnets Rolled-Out (Quads could initially be turned off, too) Single Shot Operation Send single electron bunch towards undulator Read and evaluate as much diagnostics as possible along undulator (such as BPMs, beam loss monitors, toroids) Identify and remove sources of beam loss Iterate Low Charge: 200 pC or less Diagnostics designed for micron-type resolution over 200-1000 pC range Resolution drops proportionally for out-of-range charges. Out-of-range resolution still sufficient for initial commissioning steps, which only requires resolution in the 100 micron range. Goal: Get beam through vacuum chamber with minimum losses. Reminder: Main Constraint is to Protect Undulator from Radiation Damage
  • Slide 10
  • October 30, 2007 Heinz-Dieter Nuhn, SLAC / LCLS Undulator Commissioning Plans Nuhn@slac.stanford.edu 10 First System Commissioning (A) All Undulators in Roll-Out Position BBA Commissioning with Undulator Segments Rolled-Out BFW Scan with Undulator Segments Rolled-Out ADS Check-Out with Beam (B) Roll-In Undulators Transport Beam through individual Undulator Segments Start at slot #33 (last Undulator Segment in line) Check and correct trajectory change. Transport Beam through multiple Undulator Segments Start at last Check and correct trajectory change. BBA Commissioning with Undulator Segments inserted. (A) All Undulators in Roll-Out Position BBA Commissioning with Undulator Segments Rolled-Out BFW Scan with Undulator Segments Rolled-Out ADS Check-Out with Beam (B) Roll-In Undulators Transport Beam through individual Undulator Segments Start at slot #33 (last Undulator Segment in line) Check and correct trajectory change. Transport Beam through multiple Undulator Segments Start at last Check and correct trajectory change. BBA Commissioning with Undulator Segments inserted.
  • Slide 11
  • October 30, 2007 Heinz-Dieter Nuhn, SLAC / LCLS Undulator Commissioning Plans Nuhn@slac.stanford.edu 11 Commissioning of X-Ray Diagnostics Direct Imager Calorimeter Spectrometer Slit Solid Attenuator Gas Attenuator Ion-Chamber Beam-Based K Measurement Components Direct Imager Calorimeter Spectrometer Slit Solid Attenuator Gas Attenuator Ion-Chamber Beam-Based K Measurement Components Minimum Requirement
  • Slide 12
  • October 30, 2007 Heinz-Dieter Nuhn, SLAC / LCLS Undulator Commissioning Plans Nuhn@slac.stanford.edu 12 X Ray Diagnostics Solid Attenuator Gas Attenuator Slit Start of Experimental Hutches 5 mm diameter collimators Muon Shield Hard X-Ray Offset mirror system Total Energy Thermal Detector WFOV NFOV Gas Detector e-e- Direct Imager Hard x-ray Monochromator (K Spectrometer) Soft X- ray Imager Soft X-Ray Offset mirror system
  • Slide 13
  • October 30, 2007 Heinz-Dieter Nuhn, SLAC / LCLS Undulator Commissioning Plans Nuhn@slac.stanford.edu 13 Characterization of Spontaneous Radiation Initially at 1.5 Angstrom to reduce damage issue Start at low charge Repetition rate of 10 Hz or lower will be sufficient Start to characterize radiation at last undulator Measure: total spontaneous energy / pulse spontaneous radiation spectrum wavelength of first harmonic spatial distribution around first spontaneous harmonic first harmonic wavelength spread spontaneous beam direction temporal variation in spontaneous beam parameters Characterize radiation from each individual Undulator Measure relative K of Undulator pair. Initially at 1.5 Angstrom to reduce damage issue Start at low charge Repetition rate of 10 Hz or lower will be sufficient Start to characterize radiation at last undulator Measure: total spontaneous energy / pulse spontaneous radiation spectrum wavelength of first harmonic spatial distribution around first spontaneous harmonic first harmonic wavelength spread spontaneous beam direction temporal variation in spontaneous beam parameters Characterize radiation from each individual Undulator Measure relative K of Undulator pair.
  • Slide 14
  • October 30, 2007 Heinz-Dieter Nuhn, SLAC / LCLS Undulator Commissioning Plans Nuhn@slac.stanford.edu 14 K Measurement: 2-Segment Scheme Measure synchrotron radiation spectrum produced by two undulator segments, and scan K of one segment Ks are matched when spectrum has the steepest slope on high energy side of 1st harmonic peak. Match segments pair wise until all segments are measured. undulator segments (33 total) segments under test
  • Slide 15
  • October 30, 2007 Heinz-Dieter Nuhn, SLAC / LCLS Undulator Commissioning Plans Nuhn@slac.stanford.edu 15 Angle-Integrated Spontaneous Spectrum for 2 Undulators with K/K = 0.2 to +0.2% 0.1% rms e energy jitter 0.003% rms e energy meas. resolution 2% rms charge jitter 0.5% charge meas. res. 0.5 rms angle jitter 10 5 photons/pulse/0.01% 100 photon noise 100 beam pulses with natural energy jitter only 0.1% rms e energy jitter 0.003% rms e energy meas. resolution 2% rms charge jitter 0.5% charge meas. res. 0.5 rms angle jitter 10 5 photons/pulse/0.01% 100 photon noise 100 beam pulses with natural energy jitter only = 0 K/K = 0.2% K/K = 0.2% K/K = 0% ~10 6 photons/nC/0.01%BW x = 3 mm Simulations P. Emma
  • Slide 16
  • October 30, 2007 Heinz-Dieter Nuhn, SLAC / LCLS Undulator Commissioning Plans Nuhn@slac.stanford.edu 16 First Lasing at 15 Angstrom Start with reduced number of undulators Redo BBA after change of undulator configuration Adjust tapering for spontaneous radiation losses, wakefields etc. Verify that electron beam meets requirements Use Laser Heater modulation method for increased sensitivity Find SASE signal using Direct Imager or Calorimeter Optimize Gain Start with reduced number of undulators Redo BBA after change of undulator configuration Adjust tapering for spontaneous radiation losses, wakefields etc. Verify that electron beam meets requirements Use Laser Heater modulation method for increased sensitivity Find SASE signal using Direct Imager or Calorimeter Optimize Gain
  • Slide 17
  • October 30, 2007 Heinz-Dieter Nuhn, SLAC / LCLS Undulator Commissioning Plans Nuhn@slac.stanford.edu 17 Desirable measurements as function of position along undulator : Intensity (L G, Saturation) Spectral distribution Bunching Desirable measurements after undulator : Pulse length Spatial shape and centroid Divergence Desirable measurements as function of position along undulator : Intensity (L G, Saturation) Spectral distribution Bunching Desirable measurements after undulator : Pulse length Spatial shape and centroid Divergence FEL Measurements Undulator Regime Exponential Gain Regime Saturation 1 % of X-Ray Pulse Electron Bunch Micro-Bunching
  • Slide 18
  • October 30, 2007 Heinz-Dieter Nuhn, SLAC / LCLS Undulator Commissioning Plans Nuhn@slac.stanford.edu 18 Trajectory Distortion Method GENESIS Simulations by Z. Huang Quadrupole Displacement at Selectable Point along Undulator z-dependent x-ray measurement using e-beam kick
  • Slide 19
  • October 30, 2007 Heinz-Dieter Nuhn, SLAC / LCLS Undulator Commissioning Plans Nuhn@slac.stanford.edu 19 Undulator Roll-Out Method Undulator Segments can be removed by remote control from the end of the undulator. They will not effect radiation produced by earlier segments. z-dependent x-ray measurement using rollout
  • Slide 20
  • October 30, 2007 Heinz-Dieter Nuhn, SLAC / LCLS Undulator Commissioning Plans Nuhn@slac.stanford.edu 20 LCLS FEL Commissioning (2008 - 2009) Oct 22,2008:LTU/Undulator/Dump Ready for Beam Nov 3, 2008:Re-commission Inj./BC1/BC2/Linac to SL2 (

Recommended

View more >