LCLS Commissioning Results Plans P Emma for the

LCLS Commissioning: Results & Plans P. Emma, for the LCLS Commissioning Team LCLS FAC Meeting June 16, 2008 LCLS Phys. Rev. publication: http: //prst-ab. aps. org/pdf/PRSTAB/v 11/i 3/e 030703 May 13, 2008 LCLS FAC 1 Paul Emma, et al. Emma@SLAC. Stanford. edu

LCLS Accelerator Layout 6 Me. V z 0. 83 mm 0. 05 % 4. 30 Ge. V z 0. 022 mm 0. 71 % 21 -1 b, c, d DL 1 L 12 m R 56 0 Linac-2 L 330 m rf -41° X BC 1 L 6 m R 56 -39 mm Injector Commissioned (‘ 07) 21 -3 b 24 -6 d BC 2 L 22 m R 56 -25 mm 25 -1 a 30 -8 c undulator L =130 m DL 2 L =275 m Commissioned in Jan. 2008 R 56 0 SLAC linac tunnel LCLS FAC Linac-3 L 550 m rf 0° beam parked here , b -a L 0 Linac-1 L 9 m rf -25° . . . existing linac May 13, 2008 13. 6 Ge. V z 0. 022 mm 0. 01 % Linac-X L =0. 6 m rf= -160 Linac-0 L =6 m rf gun 250 Me. V z 0. 19 mm 1. 6 % 135 Me. V z 0. 83 mm 0. 10 % 2 research yard Paul Emma, et al. Emma@SLAC. Stanford. edu

LCLS Injector Layout 6 Me. V in ‘ 0 7 OTR screens (7) YAG screens (7) Wire scanners (7) Dipole magnets (8) Beam stoppers (2) S-band RF acc. sections (5) C om m is si on ed RF Gun Solenoid L 0 a Gun Spectrometer L 0 b Emittance Screens/Wires Emittance Screen/Wires RF Deflector L 1 S 2 -km point in 3 -km SLAC linac X-band RF acc. section 135 -Me. V Spectrometer 135 Me. V May 13, 2008 LCLS FAC BC 1 TD 11 stopper 250 Me. V 3 Paul Emma, et al. Emma@SLAC. Stanford. edu

LCLS BC 2 Area Layout (sector 24/25) OTR screens (3) Collimator jaws (2 Phase monitor cavity (1) Dipole magnets (4) Kicker magnet (1) Transverse RF deflector (1) S-band RF acc. sections New installation in fall ‘ 07 4 wire-scanners “de-scoped” 4 wire-scanners in sec-28 (300 m downstream) CE 21 BPMS 21 OTR 21 BC 2 (not to scale) May 13, 2008 LCLS FAC PH 03 BXKIK TCAV 3 (25 -2 d) OTR 22 (25 -3 d) OTR_TCAV (25 -9) 4. 3 Ge. V 4 Paul Emma, et al. Emma@SLAC. Stanford. edu

Commissioning Highlights Injector commissioning: April through August, 2007 (DONE) Phase-II commissioning: Dec. Complete 3/31/08 (BC 2 + Linac) Up to 1 n. C of bunch charge available (mostly 0. 25 & 0. 5 n. C used) Great laser uptime (99%) and good performance (again) Emittances 1 mm after BC 1 at 1 n. C, 250 Me. V (fairly routine) Routine e- to 14 Ge. V (24/7 except Wed. - ~90% up-time) BC 1 dipoles & chicane motion fixed! No emittance growth in X-band RF cavity when best steered BC 2 compression demonstrated (no dipole field quality issues) CSR effects measured in BC 1 & BC 2 – agree with codes so far Many beam (8) & RF (8) feedback systems running well Tested energy switching: 14, 10, 7. 0, 4. 3 Ge. V (<5 min. switch) Coherent OTR observed – compromises nearly all screens Gun RF probes changed in April ’ 08 (allows 120 -Hz) May 13, 2008 LCLS FAC 5 Paul Emma, et al. Emma@SLAC. Stanford. edu

Design and Typical Measured Parameters May 13, 2008 LCLS FAC 6 Paul Emma, et al. Emma@SLAC. Stanford. edu

“Problems/Issues” from July ‘ 07 DOE Review AL L FI XE D Gun Faraday cup broken Gun toroid shorted during installation Some YAG screens not installed properly BC 1 motion control limited (300 mm 260 mm) Cathode QE about 5 -times lower than design Some controls tools late (orbit displays, fitting, magnet control & alarms) MCOR power supply ADC readback noise (fixed) Laser phase drift and lock trouble until mid-June May 13, 2008 LCLS FAC 7 Paul Emma, et al. Emma@SLAC. Stanford. edu

Laser Spatial and Temporal Shaping 2007 2008 2007 2 R = 1. 4 mm 6. 6 ps 7. 2 ps Temporal shape (6. 6 ps FWHM) Spatial shape on cathode using iris 99% Drive Laser up time! S. Gilevich, G. Hays, P. Hering, A. Miahnahri, W. White May 13, 2008 LCLS FAC 8 Paul Emma, et al. Emma@SLAC. Stanford. edu

Powerful Scanning/Correlation Application Watch profiles as scan proceeds H. Loos Quickly minimize emittance by scanning any parameter May 13, 2008 LCLS FAC 9 Paul Emma, et al. Emma@SLAC. Stanford. edu

Projected Emittance <1. 2 μm at 1 n. C (135 Me. V) s = 60 μm m in ee j go ect ts al or s gex = 1. 07 μm gey = 1. 11 μm May 13, 2008 LCLS FAC 10 Paul Emma, et al. Emma@SLAC. Stanford. edu

inj ec to ri s OTR screen at 135 Me. V st ab le Injector Emittance Measured Over 3 Days (0. 25 n. C) wire-scanner at 250 Me. V after BC 1 gex = 0. 91, gey = 1. 01 gex gey gex = 0. 83, gey = 0. 83 J. Welch May 13, 2008 LCLS FAC 11 Paul Emma, et al. Emma@SLAC. Stanford. edu

Laser & Electron-Based Feedback Systems ru no nn w in g Transverse Loops: Laser spot on cathode (2) Gun launch angle Injector trajectory X-band cavity position Linac trajectory (2 old) Undulator traj. (future) Laser gun (bunch length feedback still needs work) V 0 L 0 D. Fairley J. Wu J. Frisch May 13, 2008 LCLS FAC Longitudinal Loops: DL 1 energy BC 1 bunch length BC 2 energy BC 2 bunch length Final energy (old loop) 0 1 z 2 1 2 V 1 L 1 DL 1 z 1 X 2 V 2 L 2 BC 1 3 V 3 L 3 BC 2 12 BPMs CSR detectors Steering Loop DL 2 Paul Emma, et al. Emma@SLAC. Stanford. edu

Bunch Length & Energy Feedback Systems DL 1 energy BC 1 energy 0. 03% rms 0. 05% rms BC 2 energy DL 2 energy 0. 09% rms 0. 03% rms 216 ± 12 A BC 1 peak current 2170 ± 217 A BC 2 peak current Charge feedback: Q = 0. 25 n. C bunch DQ 2 1/2/Q = 1. 5% charge May 13, 2008 LCLS FAC 13 Paul Emma, et al. Emma@SLAC. Stanford. edu

BC 1 Dipole Field Quality Fixed Poles were milled off and wider poles were bolted on and then the fields were shimmed. fix ed Nov. ‘ 07 Sext. tolerance Aug. ‘ 07 ± 3 beam J. Welch, S. De. Barger, N. Li, et al. May 13, 2008 LCLS FAC 14 Paul Emma, et al. Emma@SLAC. Stanford. edu

BC 2 Dipole Field Quality OK Beam energy scans confirm BC 2 dipole field quality meets requirements ± 3 beam OK No measurable quad field and sextupole is just at tolerance May 13, 2008 LCLS FAC 15 Paul Emma, et al. Emma@SLAC. Stanford. edu

Operating Point Summary Display Shows operators the main machine parameter targets and their present settings & includes save/restore files H. -D. Nuhn May 13, 2008 LCLS FAC 16 Paul Emma, et al. Emma@SLAC. Stanford. edu

BPM-Measured CSR Energy Loss in BC 1 at 0. 25 n. C (compares well with tracking) BPM Bunch length after BC 1 measured with transverse RF L 1 S BC 1 (250 Me. V) BC 2 OFF BSY (14 Ge. V) TCAV (5. 0 Ge. V) A Phase shift of -0. 4 deg is added to the Elegant curves Y. Ding, Z. Huang Elegant CSR energy loss after BC 1 measured with BPM e- operating point g Chicane Bend May 13, 2008 LCLS FAC 17 BPM Paul Emma, et al. Emma@SLAC. Stanford. edu

Hor. CSR Emittance Growth after BC 1 (250 Me. V, 0. 25 n. C) x = 38 mm = -22º x = 55 mm = -26º x = 246 mm = -27º Now plot horizontal emittance after BC 1 Horizontal emittance after BC 1 vs. RF phase Elegant May 13, 2008 LCLS FAC Elegant Meas-1 Meas-2 operating point Data also exists at 1 n. C and BC 2 data (0. 25 n. C) also shows decent results 18 Vertical emittance after BC 1 is almost unaffected Y. Ding, Z. Huang Elegant Paul Emma, et al. Emma@SLAC. Stanford. edu

RF Phase and Amplitude Stability (e. g. , L 0 a) 0. 05% rms (<0. 07%) New inj. RF systems meet jitter tolerances RF Feedback Running 20 -second sample at 10 Hz 0. 05º rms (<0. 07º) R. Akre, D. Kotturi, J. Craft, V. Pacak, et al. May 13, 2008 LCLS FAC 19 Paul Emma, et al. Emma@SLAC. Stanford. edu

Normalized phase space centroid jitter after BC 1 (~4% of rms beam size) RMS Ay. N = 3. 4% RMS Ax. N = 3. 9% Stability is not so far off of our goals (~10%) 1 -s beam size D. Ratner … near end of linac (~12% of rms beam size, but sometimes larger) RMS Ay. N = 9% RMS Ax. N = 14% DE/E jitter 0. 03% DQ/Q jitter 1. 5% Q = 0. 25 n. C May 13, 2008 LCLS FAC Thanks to Controls group for new BPM electronics! 20 Paul Emma, et al. Emma@SLAC. Stanford. edu

BC 2 Chicane in the Linac at 4. 3 Ge. V Bob Fuller Chicane length 24 m, 4. 3 Ge. V, 2º bends May 13, 2008 LCLS FAC 21 Paul Emma, et al. Emma@SLAC. Stanford. edu

Bunch Compression Measured after BC 2 (0. 25 n. C) z < 10 mm Bunch length after BC 2 measured with transverse RF old screen used – poor resolution limit z > 25 mm sz 10 mm -2º shift applied to simulation L 2 May 13, 2008 LCLS FAC BC 2 (4. 3 Ge. V) TCAV (5. 0 Ge. V) 22 550 m BSY (14 Ge. V) Paul Emma, et al. Emma@SLAC. Stanford. edu

Longitudinal Phase Space at 14 Ge. V PR 55 Li. Track simulation Bunch is Over-Compressed L 2 phase = -41 deg Chirp knob = -450 Me. V measurement Vertical scale only approx. Transverse RF is ON PR 55 Bunch is Under-Compressed L 2 phase = -41 deg Chirp knob = +450 Me. V older screen has poor resolution Q = 1 n. C May 13, 2008 LCLS FAC Li. Track simulation measurement 23 Vertical scale only approx. Paul Emma, et al. Emma@SLAC. Stanford. edu

Emittance Measurements at End of Linac Using Wire Scanners x = 76 mm x = 38 mm x = 49 mm x = 47 mm wire scans F. -J. Decker R. Iverson Emittance measured 300 m after BC 2 at 10 Ge. V with 10 mm bunch length gey = 0. 9 mm May 13, 2008 LCLS FAC Q = 0. 25 n. C Results still variable – requires careful work 24 Paul Emma, et al. Emma@SLAC. Stanford. edu

Emittance Near End of Linac Over Long Weekend weekend run at 0. 25 n. C, with no tuning g(exey)1/2 = 1. 04 mm Saturates at 1. 5 Å in 100 m (assuming BBA, etc) (3. 3 days) May 24, 2008 00: 01 to May 27 09: 00 May 13, 2008 LCLS FAC 25 Paul Emma, et al. Emma@SLAC. Stanford. edu

Measuring Bunch Arrival Time Jitter Q = 0. 25 n. C S-band (2856 MHz) BPM V (t ) slope = -2. 34 mm/deg BPM Y Position (mm) e- Now measure BPM jitter both with transverse RF OFF, and then ON (at constant phase) TCAV OFF TCAV ON 9 mm rms 110 mm rms Dt ± 0. 6 ps Timing Jitter (w. r. t. RF) = (110 mm)/(2. 34 mm/deg) = 0. 047 deg 46 fsec rms May 13, 2008 LCLS FAC 26 Paul Emma, et al. Emma@SLAC. Stanford. edu

First Light in FEH CD-4 (7/31/2010) X-Rays in NEH FEH Hutch BO FEH Install First Light in FEE Und. Seg. Install PPS Cert. LTU/Dump FEE/NEH Install LTU/Und/Dump Install now PEP-II run ends LCLS Installation and Commissioning Time-Line PPS J F M A M J J A S ON D J F M A AM M J J A S ON D J F MAM J J Down 2008 2009 2010 Linac/BC 2 Commissioning May 13, 2008 LCLS FAC Re-commission LTU/Und NEH Operations/ Inj/BC 2 to SL 2 Comm. FEE Commissioning Comm. 27 May 2, 2008 Paul Emma, et al. Emma@SLAC. Stanford. edu

LTU/Undulator/FEE/FEL Commissioning H. Tompkins See break-out presentations: LTU & Undulator Commissioning Plans (H. -D. Nuhn) FEL/FEE Overview Commissioning Plans (H. Tompkins) FEE Diagnostics & Commissioning (R. Bionta) May 13, 2008 LCLS FAC 28 Paul Emma, et al. Emma@SLAC. Stanford. edu

Problems/Issues End-of-linac x-emittance difficult to minimize and maintain, especially at 1 n. C (CSR + micro-bunching? ) Some wire-scanner vibration issues (~fixed in April ‘ 08) Most OTR screens are unusable due to COTR (laser heater should solve this in FY 2009) Most linac BPMs need upgrade – 22 of 83 done with great resolution improvement (50 5 mm - more on AIP List) BC 2 bunch length monitor noisy or real jitter – (need beam synchronous acquisition for RF & BPMs or m-bunching? ) RF phase jumps/drifts not uncommon – sometimes beyond feedback control range May 13, 2008 LCLS FAC 29 Paul Emma, et al. Emma@SLAC. Stanford. edu

Summary Drive laser very reliable – performs well (great team) Injector in very good shape – runs well after setup Many measurements made – getting to know machine Emittances at end of linac difficult to tune, but nice results are possible with effort (gey is done!) Very encouraging results: e- beam supports 1. 5 -Å SASE We look forward to next phase (LTU, undulator, FEL, …) – preparations have begun (plans, software, checkout, …) Thanks to dedicated Commissioning Team + Controls, RF, Engineering, Operations, ASD, Maintenance, etc May 13, 2008 LCLS FAC 30 Paul Emma, et al. Emma@SLAC. Stanford. edu

DONE May 13, 2008 LCLS FAC 31 Paul Emma, et al. Emma@SLAC. Stanford. edu

gex near end of linac (µm) BC 2 Emittance Growth vs. Peak Current Q = 0. 5 n. C May 13, 2008 LCLS FAC BC 2 Peak Current Feedback Set-Point (A) 32 Paul Emma, et al. Emma@SLAC. Stanford. edu

COTR After BC 2 OTR screen just after BC 2 OTR 22 with BC 2 screen OUT (m-bunching present – COTR!) with BC 2 screen inserted (smoothes m-bunching) May 13, 2008 LCLS FAC 33 Paul Emma, et al. Emma@SLAC. Stanford. edu

m-Bunching in BC 2 May Blow up X-Emittance OTR screen in BC 2 OTR 21 gex, y measured with gex wire-scanners 320 -m downbeam of BC 2 gey May 13, 2008 LCLS FAC 34 Paul Emma, et al. Emma@SLAC. Stanford. edu

FY 2009 Commissioning Activities Pre-Beam Checkout (Nov-Dec ‘ 08) – check-list in prep. Re-establish injector & linac beam quality (Nov-Dec ‘ 08) – have experience First LTU Commissioning with beam (Jan-Mar ‘ 09) – lots of time ‘Undulator’/Dump Comm. without undulators (Jan-Mar ‘ 09) Calibrate & commission: RF BPMs, Loss Monitors, BFWs, ADS BBA algorithm testing (without segments) Install undulator segments (Mar ’ 09, two wks) – optimize linac again First Undulator Segments Commissioning (Mar-Apr ‘ 09) Care with first transport to minimize radiation on segments Full alignment process (BBA, BFW’s) Commission FEE Diagnostics (Apr-Jun ‘ 09) Direct Imager, Calorimeter, Slit, Solid Attenuator, Gas Detector Beam-Based K Measurement Components Optimization & characterization of SASE (Jun-Jul ‘ 09) Optimize linac beam quality (adjust compression, emittance tuning, BBA) Measure gain length May 13, 2008 LCLS FAC 35 Paul Emma, et al. Emma@SLAC. Stanford. edu