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LCLS. Beam-Based Alignment with New Parameters Paul Emma, SLAC Oct. 24, 2003. Brief Review of Technique Old Parameters New Parameters Cub Horror. j. i th BPM. D E = 0. quad offsets and/or pole errors. D E < 0. The Method. - PowerPoint PPT Presentation
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LCLS Undulator Workshop, Oct. 24, 2003LCLS Undulator Workshop, Oct. 24, 2003 Paul Emma, SLACPaul Emma, SLACBeam-Based Alignment with New Parameters [email protected]@SLAC.Stanford.edu
Linac Coherent Light Source Stanford Synchrotron Radiation LaboratoryStanford Linear Accelerator Center
Beam-Based Alignment with New Parameters
Paul Emma, SLACOct. 24, 2003
Beam-Based Alignment with New Parameters
Paul Emma, SLACOct. 24, 2003
Brief Review of TechniqueBrief Review of Technique Old ParametersOld Parameters New ParametersNew Parameters Cub HorrorCub Horror
Brief Review of TechniqueBrief Review of Technique Old ParametersOld Parameters New ParametersNew Parameters Cub HorrorCub Horror
LCLSLCLS
LCLS Undulator Workshop, Oct. 24, 2003LCLS Undulator Workshop, Oct. 24, 2003 Paul Emma, SLACPaul Emma, SLACBeam-Based Alignment with New Parameters [email protected]@SLAC.Stanford.edu
Linac Coherent Light Source Stanford Synchrotron Radiation LaboratoryStanford Linear Accelerator Center
The MethodThe Method
BPM readings, BPM readings, mmii, written as sum of upstream kicks , written as sum of upstream kicks ++ offset, offset, bbii
Kicks are sensitive to momentum, Kicks are sensitive to momentum, ppkk, while offsets, , while offsets, bbii, are not, are not
BPM readings, BPM readings, mmii, written as sum of upstream kicks , written as sum of upstream kicks ++ offset, offset, bbii
Kicks are sensitive to momentum, Kicks are sensitive to momentum, ppkk, while offsets, , while offsets, bbii, are not, are not
ss
bbii > 0 > 0
EE = 0 = 0
EE < 0 < 0quad offsets and/or pole errorsquad offsets and/or pole errors
iithth BPM BPM jj
LCLS Undulator Workshop, Oct. 24, 2003LCLS Undulator Workshop, Oct. 24, 2003 Paul Emma, SLACPaul Emma, SLACBeam-Based Alignment with New Parameters [email protected]@SLAC.Stanford.edu
Linac Coherent Light Source Stanford Synchrotron Radiation LaboratoryStanford Linear Accelerator Center
Reference line defined by incoming Reference line defined by incoming xx00, , xx00 launch conditions launch conditionsReference line defined by incoming Reference line defined by incoming xx00, , xx00 launch conditions launch conditions
...The Method...The Method
1/1/pp
mmii
offset = bi
(15 GeV/c)(15 GeV/c)11 (7.0 GeV/c)(7.0 GeV/c)11 (4.5 GeV/c)(4.5 GeV/c)11pp
linear only if linear only if CCijij independent of independent of pp
LCLS Undulator Workshop, Oct. 24, 2003LCLS Undulator Workshop, Oct. 24, 2003 Paul Emma, SLACPaul Emma, SLACBeam-Based Alignment with New Parameters [email protected]@SLAC.Stanford.edu
Linac Coherent Light Source Stanford Synchrotron Radiation LaboratoryStanford Linear Accelerator Center
Schematic layoutSchematic layout
~300 ~300 mm
UNDULATORUNDULATOR(122 m)(122 m)
LINACLINACbest final trajectorybest final trajectory
steering elementssteering elements
xx00xx00
initial incoming initial incoming launch errorlaunch error
Undulator misaligned w.r.t. linac axis with uncorrelated Undulator misaligned w.r.t. linac axis with uncorrelated and correlatedand correlated** (‘random walk’) component (‘random walk’) component
permanent magnet quad and permanent magnet quad and undulator polesundulator poles
* suggested by C. Adolphsen* suggested by C. Adolphsen
BPMsBPMsquadsquads
LCLS Undulator Workshop, Oct. 24, 2003LCLS Undulator Workshop, Oct. 24, 2003 Paul Emma, SLACPaul Emma, SLACBeam-Based Alignment with New Parameters [email protected]@SLAC.Stanford.edu
Linac Coherent Light Source Stanford Synchrotron Radiation LaboratoryStanford Linear Accelerator Center
Possible Absolute TrajectoryPossible Absolute Trajectory
LINACLINAC
Beam is launched straight down undulator, with Beam is launched straight down undulator, with possible inconsequential kink at boundarypossible inconsequential kink at boundary
dispersion generated is insignificantdispersion generated is insignificant
LCLS Undulator Workshop, Oct. 24, 2003LCLS Undulator Workshop, Oct. 24, 2003 Paul Emma, SLACPaul Emma, SLACBeam-Based Alignment with New Parameters [email protected]@SLAC.Stanford.edu
Linac Coherent Light Source Stanford Synchrotron Radiation LaboratoryStanford Linear Accelerator Center
Input errors used for simulationInput errors used for simulation
0.040.04
00 44
100100
100100
22
LCLS Undulator Workshop, Oct. 24, 2003LCLS Undulator Workshop, Oct. 24, 2003 Paul Emma, SLACPaul Emma, SLACBeam-Based Alignment with New Parameters [email protected]@SLAC.Stanford.edu
Linac Coherent Light Source Stanford Synchrotron Radiation LaboratoryStanford Linear Accelerator Center
Natural Undulator Natural Undulator YY-Focusing Now Included-Focusing Now IncludedNatural Undulator Natural Undulator YY-Focusing Now Included-Focusing Now Included
Recently included Recently included natural focusingnatural focusing in in YY-plane-plane
No change if included in both No change if included in both simulationsimulation and and reconstructionreconstruction
Small change if not included in reconstruction (not shown)Small change if not included in reconstruction (not shown)
Thanks to H.-D. Nuhn, S. Reiche, J. Welch Thanks to H.-D. Nuhn, S. Reiche, J. Welch
Recently included Recently included natural focusingnatural focusing in in YY-plane-plane
No change if included in both No change if included in both simulationsimulation and and reconstructionreconstruction
Small change if not included in reconstruction (not shown)Small change if not included in reconstruction (not shown)
Thanks to H.-D. Nuhn, S. Reiche, J. Welch Thanks to H.-D. Nuhn, S. Reiche, J. Welch
LCLS Undulator Workshop, Oct. 24, 2003LCLS Undulator Workshop, Oct. 24, 2003 Paul Emma, SLACPaul Emma, SLACBeam-Based Alignment with New Parameters [email protected]@SLAC.Stanford.edu
Linac Coherent Light Source Stanford Synchrotron Radiation LaboratoryStanford Linear Accelerator Center
Initial BPM and quad misalignments (w.r.t. linac axis)Initial BPM and quad misalignments (w.r.t. linac axis)
++ Quadrupole Quadrupole positionspositions
oo BPM BPM offsetsoffsets
quad positionsquad positions
BPM offsetsBPM offsetsNow launch Now launch beam through beam through undulatorundulator
LCLS Undulator Workshop, Oct. 24, 2003LCLS Undulator Workshop, Oct. 24, 2003 Paul Emma, SLACPaul Emma, SLACBeam-Based Alignment with New Parameters [email protected]@SLAC.Stanford.edu
Linac Coherent Light Source Stanford Synchrotron Radiation LaboratoryStanford Linear Accelerator Center
Initial trajectory before any correction appliedInitial trajectory before any correction applied
++ Quadrupole Quadrupole positionspositions
oo BPM BPM readbackreadback
ee trajectory trajectory
‘‘real’ trajectoryreal’ trajectory
quad positionsquad positionsBPM readingsBPM readings
LCLS Undulator Workshop, Oct. 24, 2003LCLS Undulator Workshop, Oct. 24, 2003 Paul Emma, SLACPaul Emma, SLACBeam-Based Alignment with New Parameters [email protected]@SLAC.Stanford.edu
Linac Coherent Light Source Stanford Synchrotron Radiation LaboratoryStanford Linear Accelerator Center
After 3rd pass of BBA with old parameters (14.3 GeV)After 3rd pass of BBA with old parameters (14.3 GeV)
++ Quadrupole Quadrupole positionspositions
oo BPM readback BPM readback
ee trajectory trajectory
RON RON (FEL-code) (FEL-code) simulation shows simulation shows LLsatsat increased by increased by
<1 gain-length;<1 gain-length;R. Dejus, R. Dejus, N.VinokurovN.Vinokurov
300°300° 300°300°
xx 7 7 mmxx 7 7 mm
yy 6 6 mmyy 6 6 mm
rms beam size: rms beam size: 28 28 mm
LCLS Undulator Workshop, Oct. 24, 2003LCLS Undulator Workshop, Oct. 24, 2003 Paul Emma, SLACPaul Emma, SLACBeam-Based Alignment with New Parameters [email protected]@SLAC.Stanford.edu
Linac Coherent Light Source Stanford Synchrotron Radiation LaboratoryStanford Linear Accelerator Center
After 3rd pass of BBA with new parametersAfter 3rd pass of BBA with new parameters
++ Quadrupole Quadrupole positionspositions
oo BPM readback BPM readback
ee trajectory trajectory
73°73° 73°73°xx 2.6 2.6 mmxx 2.6 2.6 mm
yy 2.7 2.7 mmyy 2.7 2.7 mm
rms beam size: rms beam size: 33 33 mm
14 – 7.0 – 4.5 GeV14 – 7.0 – 4.5 GeV
LCLS Undulator Workshop, Oct. 24, 2003LCLS Undulator Workshop, Oct. 24, 2003 Paul Emma, SLACPaul Emma, SLACBeam-Based Alignment with New Parameters [email protected]@SLAC.Stanford.edu
Linac Coherent Light Source Stanford Synchrotron Radiation LaboratoryStanford Linear Accelerator Center
Now try 2-times worse initial random misalignmentsNow try 2-times worse initial random misalignments
++ Quadrupole Quadrupole positionspositions
oo BPM BPM offsetsoffsets
quad positionsquad positions
BPM offsetsBPM offsets 2-2-mm BPM BPM resolution + resolution + 100-100-mm initial initial BPM & quad BPM & quad offsets + offsets + 2-2-mm mover mover backlashbacklash
LCLS Undulator Workshop, Oct. 24, 2003LCLS Undulator Workshop, Oct. 24, 2003 Paul Emma, SLACPaul Emma, SLACBeam-Based Alignment with New Parameters [email protected]@SLAC.Stanford.edu
Linac Coherent Light Source Stanford Synchrotron Radiation LaboratoryStanford Linear Accelerator Center
After 3rd pass , new parameters, combined ‘worst case’After 3rd pass , new parameters, combined ‘worst case’
2-2-mm BPM BPM resolution + resolution + 100-100-mm initial initial BPM & quad BPM & quad offsets + offsets + 2-2-mm mover mover backlashbacklash
184°184° 184°184°
xx 4.9 4.9 mmxx 4.9 4.9 mm
yy 6.0 6.0 mmyy 6.0 6.0 mm
LCLS Undulator Workshop, Oct. 24, 2003LCLS Undulator Workshop, Oct. 24, 2003 Paul Emma, SLACPaul Emma, SLACBeam-Based Alignment with New Parameters [email protected]@SLAC.Stanford.edu
Linac Coherent Light Source Stanford Synchrotron Radiation LaboratoryStanford Linear Accelerator Center
Run BBA on 25 Random ‘worst case’ SeedsRun BBA on 25 Random ‘worst case’ Seeds
2-2-mm BPM BPM resolution + resolution + 100-100-mm initial initial BPM & quad BPM & quad offsets + offsets + 2-2-mm mover mover backlashbacklash
Final Final XX-trajectories-trajectories
Final Final YY-trajectories-trajectories
LCLS Undulator Workshop, Oct. 24, 2003LCLS Undulator Workshop, Oct. 24, 2003 Paul Emma, SLACPaul Emma, SLACBeam-Based Alignment with New Parameters [email protected]@SLAC.Stanford.edu
Linac Coherent Light Source Stanford Synchrotron Radiation LaboratoryStanford Linear Accelerator Center
Run BBA on 25 Different Random ‘Worst-Case’ SeedsRun BBA on 25 Different Random ‘Worst-Case’ Seeds
2-2-mm BPM BPM resolution + resolution + 100-100-mm initial initial BPM & quad BPM & quad offsets + offsets + 2-2-mm mover mover backlashbacklash
Final Final XX-mover settings-mover settings
Final Final YY-mover settings-mover settingswider mover wider mover range at end due range at end due to lack of BPMs to lack of BPMs after undulatorafter undulator
LCLS Undulator Workshop, Oct. 24, 2003LCLS Undulator Workshop, Oct. 24, 2003 Paul Emma, SLACPaul Emma, SLACBeam-Based Alignment with New Parameters [email protected]@SLAC.Stanford.edu
Linac Coherent Light Source Stanford Synchrotron Radiation LaboratoryStanford Linear Accelerator Center
Run BBA on 25 Different Random ‘Worst-Case’ SeedsRun BBA on 25 Different Random ‘Worst-Case’ Seeds
2-2-mm BPM BPM resolution + resolution + 100-100-mm initial initial BPM & quad BPM & quad offsets + offsets + 2-2-mm mover mover backlashbacklash
xx,,yyxx & & yy mover mover distrib.distrib.
LCLS Undulator Workshop, Oct. 24, 2003LCLS Undulator Workshop, Oct. 24, 2003 Paul Emma, SLACPaul Emma, SLACBeam-Based Alignment with New Parameters [email protected]@SLAC.Stanford.edu
Linac Coherent Light Source Stanford Synchrotron Radiation LaboratoryStanford Linear Accelerator Center
Evaluation of BBA Simulation Results (old parameters)Evaluation of BBA Simulation Results (old parameters)
Trajectory (BBA & Genesis)Trajectory (BBA & Genesis) PPsatsat and and LLsatsat vs BPM res. vs BPM res.
B. Fawley, H.-D. Nuhn, S. Reiche, PEB. Fawley, H.-D. Nuhn, S. Reiche, PE
LCLS Undulator Workshop, Oct. 24, 2003LCLS Undulator Workshop, Oct. 24, 2003 Paul Emma, SLACPaul Emma, SLACBeam-Based Alignment with New Parameters [email protected]@SLAC.Stanford.edu
Linac Coherent Light Source Stanford Synchrotron Radiation LaboratoryStanford Linear Accelerator Center
SummarySummary
BPMs resolve trajectory to <2 BPMs resolve trajectory to <2 m rmsm rms
BPM readings ‘drift’ <2 BPM readings ‘drift’ <2 m over 1-2 hr (temperature)m over 1-2 hr (temperature)
Quad movers settable to better than Quad movers settable to better than 22 m, or small steering m, or small steering coils for final correctioncoils for final correction
BPM readings are not sensitive to variable beam size, etc.BPM readings are not sensitive to variable beam size, etc.
Trajectory is stable enough to <20% of beam size (already Trajectory is stable enough to <20% of beam size (already demonstrated in FFTB)demonstrated in FFTB)
Kerry Wood pitches no-hitter in openerKerry Wood pitches no-hitter in opener
BPMs resolve trajectory to <2 BPMs resolve trajectory to <2 m rmsm rms
BPM readings ‘drift’ <2 BPM readings ‘drift’ <2 m over 1-2 hr (temperature)m over 1-2 hr (temperature)
Quad movers settable to better than Quad movers settable to better than 22 m, or small steering m, or small steering coils for final correctioncoils for final correction
BPM readings are not sensitive to variable beam size, etc.BPM readings are not sensitive to variable beam size, etc.
Trajectory is stable enough to <20% of beam size (already Trajectory is stable enough to <20% of beam size (already demonstrated in FFTB)demonstrated in FFTB)
Kerry Wood pitches no-hitter in openerKerry Wood pitches no-hitter in opener
For new parameters:For new parameters: Alignment can be achieved at Alignment can be achieved at adequate level using beam-based technique, given that…adequate level using beam-based technique, given that…
LCLSLCLS
LCLS Undulator Workshop, Oct. 24, 2003LCLS Undulator Workshop, Oct. 24, 2003 Paul Emma, SLACPaul Emma, SLACBeam-Based Alignment with New Parameters [email protected]@SLAC.Stanford.edu
Linac Coherent Light Source Stanford Synchrotron Radiation LaboratoryStanford Linear Accelerator Center
Reserve SlidesReserve Slides
Next slides are in reserve for questionsNext slides are in reserve for questionsNext slides are in reserve for questionsNext slides are in reserve for questions
LCLS Undulator Workshop, Oct. 24, 2003LCLS Undulator Workshop, Oct. 24, 2003 Paul Emma, SLACPaul Emma, SLACBeam-Based Alignment with New Parameters [email protected]@SLAC.Stanford.edu
Linac Coherent Light Source Stanford Synchrotron Radiation LaboratoryStanford Linear Accelerator Center
Add 10-m random BPM offsets and correct trajectoryAdd 10-m random BPM offsets and correct trajectory
++ Quadrupole Quadrupole positionspositions
oo BPM readback BPM readback
ee trajectory trajectory
113°113° 113°113°
(old parameters)(old parameters)
LCLS Undulator Workshop, Oct. 24, 2003LCLS Undulator Workshop, Oct. 24, 2003 Paul Emma, SLACPaul Emma, SLACBeam-Based Alignment with New Parameters [email protected]@SLAC.Stanford.edu
Linac Coherent Light Source Stanford Synchrotron Radiation LaboratoryStanford Linear Accelerator Center
Wait 2 weeks, allow 3 bad BPMs, and 2 moved quadsWait 2 weeks, allow 3 bad BPMs, and 2 moved quads
++ Quadrupole Quadrupole positionspositions
oo BPM readback BPM readback
ee trajectory trajectory
1137°1137° 1137°1137°2 weeks of ‘ATL’ 2 weeks of ‘ATL’ diffusive ground diffusive ground motionmotion3 BPM offsets drift 3 BPM offsets drift by 20 by 20 mm2 quads moved by 2 quads moved by 20 20 mm
22 = = AA··TT··LL, 2 , 2 m at m at TT = 2 wk, = 2 wk, LL = 3.5 = 3.5 mm
(old parameters)(old parameters)
LCLS Undulator Workshop, Oct. 24, 2003LCLS Undulator Workshop, Oct. 24, 2003 Paul Emma, SLACPaul Emma, SLACBeam-Based Alignment with New Parameters [email protected]@SLAC.Stanford.edu
Linac Coherent Light Source Stanford Synchrotron Radiation LaboratoryStanford Linear Accelerator Center
Now correct trajectory with ‘careful’ steeringNow correct trajectory with ‘careful’ steering
++ Quadrupole Quadrupole positionspositions
oo BPM readback BPM readback
ee trajectory trajectory
173°173° 173°173°
Much beyond this Much beyond this level will require level will require repeat iteration of repeat iteration of BBABBA
xx 3.5 3.5 mmxx 3.5 3.5 mm
yy 4.8 4.8 mmyy 4.8 4.8 mm
(old parameters)(old parameters)
LCLS Undulator Workshop, Oct. 24, 2003LCLS Undulator Workshop, Oct. 24, 2003 Paul Emma, SLACPaul Emma, SLACBeam-Based Alignment with New Parameters [email protected]@SLAC.Stanford.edu
Linac Coherent Light Source Stanford Synchrotron Radiation LaboratoryStanford Linear Accelerator Center
After 3rd pass, new parameters, 2-m mover backlashAfter 3rd pass, new parameters, 2-m mover backlash
83°83° 83°83°
xx 1.8 1.8 mmxx 1.8 1.8 mm
yy 4.7 4.7 mmyy 4.7 4.7 mm
2-2-mm random random mover backlash mover backlash (uniform dist. (uniform dist. with FWHM = with FWHM = 4 4 m)m)
LCLS Undulator Workshop, Oct. 24, 2003LCLS Undulator Workshop, Oct. 24, 2003 Paul Emma, SLACPaul Emma, SLACBeam-Based Alignment with New Parameters [email protected]@SLAC.Stanford.edu
Linac Coherent Light Source Stanford Synchrotron Radiation LaboratoryStanford Linear Accelerator Center
After 3rd pass, new parameters, 4-m mover backlashAfter 3rd pass, new parameters, 4-m mover backlash
124°124° 124°124°
xx 2.5 2.5 mmxx 2.5 2.5 mm
yy 8.0 8.0 mmyy 8.0 8.0 mm
4-4-mm random random mover backlash mover backlash (uniform dist. (uniform dist. with FWHM = with FWHM = 8 8 m)m)
LCLS Undulator Workshop, Oct. 24, 2003LCLS Undulator Workshop, Oct. 24, 2003 Paul Emma, SLACPaul Emma, SLACBeam-Based Alignment with New Parameters [email protected]@SLAC.Stanford.edu
Linac Coherent Light Source Stanford Synchrotron Radiation LaboratoryStanford Linear Accelerator Center
After 3rd pass BBA, new parameters, 100-m initial alignmentAfter 3rd pass BBA, new parameters, 100-m initial alignment
100-100-mm initial initial BPM & quad BPM & quad offsets offsets (uncorrelated)(uncorrelated)
88°88° 88°88°xx 3.6 3.6 mmxx 3.6 3.6 mm
yy 2.8 2.8 mmyy 2.8 2.8 mm