Download ppt - Undulator Commissioning Plans Heinz-Dieter Nuhn, SLAC / LCLS October 30, 2007

1October 30, 2007 Heinz-Dieter Nuhn, SLAC / LCLSUndulator Commissioning Plans [email protected]

Undulator Commissioning PlansHeinz-Dieter Nuhn, SLAC / LCLS

October 30, 2007

Undulator Commissioning PlansHeinz-Dieter Nuhn, SLAC / LCLS

October 30, 2007

Getting the Undulator System Ready for Operation.Getting the Undulator System Ready for Operation.


Getting Undulator System Ready for Operation

Installation and Rough AlignmentADS Commissioning and Conventional Girder AlignmentPre-Beam CheckoutsPPS VerificationCommissioning with Beam

Commissioning of Electron Beam ComponentsCommissioning of X-Ray Beam DiagnosticsCharacterization of Spontaneous RadiationGeneration and Characterization of FEL Radiation

Transition to Operation

Installation and Rough AlignmentADS Commissioning and Conventional Girder AlignmentPre-Beam CheckoutsPPS VerificationCommissioning with Beam

Commissioning of Electron Beam ComponentsCommissioning of X-Ray Beam DiagnosticsCharacterization of Spontaneous RadiationGeneration and Characterization of FEL Radiation



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-AlignmentUsing 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-AlignmentUsing Portable WPM/HLS


Pre-Beam Checkouts

HVAC System CheckoutControl System Checkout

Network Configuration of IOC'sTiming SystemCommunication with ADS Checkout

Verification of individual Device OperationMagnet Power Supplies and InterlocksBPM Cable CheckoutBPMsBeam Finder WireUndulator Motion Control Checkout

CAM Mover Motion CheckoutTransverse Slide Motion CheckoutCompound Motion Checkout

Electro-Magnet Polarity CheckoutQuadrupole Main Coils Polarity CheckoutsQuadrupole Trim Coils Polarity Checkouts

BFW System Checkout

HVAC System CheckoutControl System Checkout

Network Configuration of IOC'sTiming SystemCommunication with ADS Checkout

Verification of individual Device OperationMagnet Power Supplies and InterlocksBPM Cable CheckoutBPMsBeam Finder WireUndulator Motion Control Checkout

CAM Mover Motion CheckoutTransverse Slide Motion CheckoutCompound Motion Checkout

Electro-Magnet Polarity CheckoutQuadrupole Main Coils Polarity CheckoutsQuadrupole Trim Coils Polarity Checkouts

BFW System Checkout


Getting Undulator System Ready for Operation

Installation and Rough AlignmentConventional Girder AlignmentPre-Beam CheckoutsPPS VerificationCommissioning with Beam

Electron Beam CommissioningCommissioning of X-Ray Beam DiagnosticsCharacterization of Spontaneous RadiationGeneration and Characterization of FEL Radiation


Installation and Rough AlignmentConventional Girder AlignmentPre-Beam CheckoutsPPS VerificationCommissioning with Beam

Electron Beam CommissioningCommissioning of X-Ray Beam DiagnosticsCharacterization of Spontaneous RadiationGeneration and Characterization of FEL Radiation



LCLS Commissioning Parameters (Inj/Lin Example)

ParameterParameter ValueValue CommentsComments

RF rateRF rate 30 Hz30 Hz 30 Hz in linac (possible short-term 120 Hz linac rate in L0-BC1 for 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 ratefeedback tests, etc) - 120 Hz in gun for short time to verify full rate

Beam rateBeam rate ≤≤30 Hz30 Hz 30 Hz e- beam as baseline – possible 120-Hz tests in L0-BC1 for 30 Hz e- beam as baseline – possible 120-Hz tests in L0-BC1 for short term verification of feedback, etcshort term verification of feedback, etc

Drive-laser rateDrive-laser rate 120 Hz120 Hz 120-Hz all the times – pulse-picker provides 120-Hz all the times – pulse-picker provides ee rate as required rate as required aboveabove

Bunch chargeBunch charge 200-500 pC200-500 pC 200-500 pC, depending on QE and diagnostics - short spans at 10 200-500 pC, depending on QE and diagnostics - short spans at 10 pC – later in ’07 we explore 1-nCpC – later in ’07 we explore 1-nC

Drive-laser pulse lengthDrive-laser pulse length 10 ps fwhm10 ps fwhm 10 ps FWHM startup with possibility of 6-ps at 0.2 nC later – early 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 laser tests may provide path to more convenient pulse-length changeschanges

Gun gradientGun gradient 120 MV/m120 MV/m 120 MV/m, although 110 MV/m is adequate in ‘07120 MV/m, although 110 MV/m is adequate in ‘07

L0-b gradientL0-b gradient 24 MV/m24 MV/m 24 MV/m in L0-b (not critical in ‘07)24 MV/m in L0-b (not critical in ‘07)


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


Electron Beam Commissioning to Tune-Up Dump

Beam and Beam Stability CharacterizationEmittanceEnergy SpreadChargeEnergyTransverse 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 CharacterizationEmittanceEnergy SpreadChargeEnergyTransverse 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)


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 undulatorRead 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 lessDiagnostics designed for micron-type resolution over 200-1000 pC rangeResolution 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 undulatorRead 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 lessDiagnostics designed for micron-type resolution over 200-1000 pC rangeResolution 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


First System Commissioning

(A) All Undulators in Roll-Out PositionBBA Commissioning with Undulator Segments Rolled-Out

BFW Scan with Undulator Segments Rolled-Out

ADS Check-Out with Beam

(B) Roll-In UndulatorsTransport Beam through individual Undulator SegmentsStart at slot #33 (last Undulator Segment in line)

Check and correct trajectory change.

Transport Beam through multiple Undulator SegmentsStart at last


BBA Commissioning with Undulator Segments inserted.

(A) All Undulators in Roll-Out PositionBBA Commissioning with Undulator Segments Rolled-Out

BFW Scan with Undulator Segments Rolled-Out

ADS Check-Out with Beam

(B) Roll-In UndulatorsTransport Beam through individual Undulator SegmentsStart at slot #33 (last Undulator Segment in line)


Transport Beam through multiple Undulator SegmentsStart at last


BBA Commissioning with Undulator Segments inserted.


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 RequirementMinimum Requirement


X Ray Diagnostics

SolidAttenuator

Gas Attenuator

Slit

Start of Experimental

Hutches

5 mm diameter

collimators

Muon Shield

Hard X-Ray Offset mirror

system

TotalEnergyThermal Detector

WFOV

NFOV

Gas Detector

Gas Detector

e-

Direct Imager

Hard x-ray Monochromator (K Spectrometer)

Soft X-ray

Imager

Soft X-Ray Offset mirror

system


Characterization of Spontaneous Radiation

Initially at 1.5 Angstrom to reduce damage issueStart at low chargeRepetition rate of 10 Hz or lower will be sufficientStart to characterize radiation at last undulator

Measure:total spontaneous energy / pulsespontaneous radiation spectrumwavelength of first harmonicspatial distribution around first spontaneous harmonicfirst harmonic wavelength spreadspontaneous beam directiontemporal variation in spontaneous beam parameters

Characterize radiation from each individual UndulatorMeasure relative K of Undulator pair.

Initially at 1.5 Angstrom to reduce damage issueStart at low chargeRepetition rate of 10 Hz or lower will be sufficientStart to characterize radiation at last undulator

Measure:total spontaneous energy / pulsespontaneous radiation spectrumwavelength of first harmonicspatial distribution around first spontaneous harmonicfirst harmonic wavelength spreadspontaneous beam directiontemporal variation in spontaneous beam parameters

Characterize radiation from each individual UndulatorMeasure relative K of Undulator pair.


K Measurement: 2-Segment Scheme

Measure synchrotron radiation spectrum produced by two undulator segments, and scan K of one segmentK’s 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


Angle-Integrated Spontaneous Spectrum for 2 Undulators with Angle-Integrated Spontaneous Spectrum for 2 Undulators with KK//KK = = 0.2 to +0.2%0.2 to +0.2%

0.1% rms 0.1% rms ee energy jitter energy jitter0.003% rms 0.003% rms ee energy energy meas. resolutionmeas. resolution2% rms charge jitter2% rms charge jitter0.5% charge meas. res.0.5% charge meas. res.0.50.5 rms angle jitter rms angle jitter101055 photons/pulse/0.01% photons/pulse/0.01%100 photon noise100 photon noise100 beam pulses with 100 beam pulses with natural energy jitter onlynatural energy jitter only

0.1% rms 0.1% rms ee energy jitter energy jitter0.003% rms 0.003% rms ee energy energy meas. resolutionmeas. resolution2% rms charge jitter2% rms charge jitter0.5% charge meas. res.0.5% charge meas. res.0.50.5 rms angle jitter rms angle jitter101055 photons/pulse/0.01% photons/pulse/0.01%100 photon noise100 photon noise100 beam pulses with 100 beam pulses with natural energy jitter onlynatural energy jitter only

= 0= 0

KK//KK = = 0.2% 0.2%

KK//KK = = 0.2% 0.2%

KK//KK = 0% = 0%

~10

~1066 p

hoto

ns/n

C/0

.01%

BW

pho

tons

/nC

/0.0

1%B

W

xx = = 3 3 mmmm

xx = = 3 3 mmmm

Simulations P. Emma


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…


Desirable measurements as function of position along undulator :

Intensity (LG, Saturation)

Spectral distribution

Bunching

Desirable measurements after undulator :

Pulse length

Spatial shape and centroid

Divergence

Desirable measurements as function of position along undulator :

Intensity (LG, Saturation)

Spectral distribution

Bunching

Desirable measurements after undulator :

Pulse length

Spatial shape and centroid

Divergence

FEL Measurements

Undulator RegimeUndulator Regime

Exponential Gain Regime

Exponential Gain Regime

Saturation

Saturation

1 % of X-Ray Pulse1 % of X-Ray Pulse

Electron BunchMicro-Bunching

Electron BunchMicro-Bunching


Trajectory Distortion Method

GENESIS Simulations by Z. Huang

Quadrupole Displacement at Selectable Point along Undulator

Quadrupole Displacement at Selectable Point along Undulator

z-dependent x-ray measurement using e-beam kickz-dependent x-ray measurement using e-beam kick


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 rolloutz-dependent x-ray measurement using rollout


LCLSLCLS FEL Commissioning (2008 - 2009) FEL Commissioning (2008 - 2009)

Oct 22,Oct 22, 2008:2008: LTU/Undulator/Dump Ready for BeamLTU/Undulator/Dump Ready for Beam

Nov 3, Nov 3, 2008:2008: Re-commission Inj./BC1/BC2/Linac to SL2 (<1 mo)Re-commission Inj./BC1/BC2/Linac to SL2 (<1 mo)

Nov 25, Nov 25, 2008:2008: Commission LTU up to “TDUND” (<2 mo)Commission LTU up to “TDUND” (<2 mo)

Jan 19, Jan 19, 2009:2009: Commission Undulator & Dump (3 mo)Commission Undulator & Dump (3 mo)

May 14, May 14, 2009:2009: FEE Ready for Beam (move earlier?)FEE Ready for Beam (move earlier?)

May 15, May 15, 2009:2009: First Spontaneous LightFirst Spontaneous Light

May 15, May 15, 2009:2009: FEL/FEE Commissioning (~1 mo)FEL/FEE Commissioning (~1 mo)

Jun 18, Jun 18, 2009:2009: Measure photon flux density in FEEMeasure photon flux density in FEE

Jun 19, Jun 19, 2009:2009: Commission FEE Soft X-ray Mirrors @ 15 Å (1 mo)Commission FEE Soft X-ray Mirrors @ 15 Å (1 mo)

Jul 17, Jul 17, 2009:2009: X-rays in NEHX-rays in NEH

Jul 31, Jul 31, 2009:2009: First FEL LightFirst FEL Light

Aug 1, Aug 1, 2009:2009: FEL Optimization (1 mo)FEL Optimization (1 mo)

Sep 1, Sep 1, 2009:2009: X-rays to Users in NEH @ 15 X-rays to Users in NEH @ 15 ÅÅ (1 mo) (1 mo)

Oct 1, Oct 1, 2009:2009: Shutdown for PPS Certification (1 mo)Shutdown for PPS Certification (1 mo)

Sep. 14, 2007Sep. 14, 2007(beam rate 30 Hz)

LATE


Summary

Plans for undulator commissioning are shaping up.

Detailed system checkout planned.

Diagnostics tools are at, or passed, the concept phase.

Beam based K-measurement method included.

Methods for gain curve measurements have been worked out.

Planned availability of x-ray diagnostics is late Early x-ray profile and intensity diagnostics after main dump, desirable.

Plans for undulator commissioning are shaping up.

Detailed system checkout planned.

Diagnostics tools are at, or passed, the concept phase.

Beam based K-measurement method included.

Methods for gain curve measurements have been worked out.

Planned availability of x-ray diagnostics is late Early x-ray profile and intensity diagnostics after main dump, desirable.


End of Presentation