Commissioning of the European XFEL Accelerator Winfried Decking, Hans Weise - DESY for the European XFEL Accelerator Consortium and Commissioning Team
IPAC 2017, Copenhagen Commissioning of the European XFEL Accelerator
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IPAC ‘17, 15.5.2017 Winni Decking, DESY Commissioning of the European XFEL Accelerator
European XFEL at a Glance 3 ¢ International project realised in Hamburg area, Germany ¢ 17.5 GeV superconducting linac, 500 kW beam power ¢ 27000 pulses per second in 10 Hz burst mode ¢ Three variable gap undulators for hard and soft X-rays ¢ Initially 6 equipped experiments ¢ All accelerator and beamlines in tunnels 6 -25 m below surface
Experimental Hall Photon Beam Lines Beam Dumps Undulators
Electron Beam Distribution Collimation Linear Accelerator Bunch Compressors Injector
IPAC ‘17, 15.5.2017 Winni Decking, DESY Commissioning of the European XFEL Accelerator
Covers photon energies from 0.25 keV to 25 keV 4 SASE3 SASE 1& SASE 2 17.5 Soft X-rays 0.25 – ≥ 3 keV Hard X-rays 3.0 – ~25 keV 14.0
Electron 12.0
Energy [GeV] 8.5 0.2 1 2 10 20 Photon Energy [keV]
IPAC ‘17, 15.5.2017 Winni Decking, DESY Commissioning of the European XFEL Accelerator
Project History 5 2000: First lasing at 109 nm at the Tesla Test Facility (TTF), now FLASH 2001: TESLA Linear Collider TDR with XFEL appendix 2002: TESLA TDR supplement with stand-alone XFEL 2006: European XFEL TDR 2009: Foundation of the European XFEL GmbH Start of underground construction 2010: Formation of the Accelerator Consortium: 16 accelerator institutes under the coordination of DESY 2012: End of tunnel construction
Start of underground installation M. Bousonville, TUPAB039 2016: Finish of accelerator installation J. Kreutzkamp, WEPAB018, THPAB104 Start of commissioning
IPAC ‘17, 15.5.2017 Winni Decking, DESY Commissioning of the European XFEL Accelerator
Accelerator Overview 6
Injector L1 L2 L3
V0, 1.3 GHz ≈ 0.16 GV V0 ≈ 0.65 GV V0 ≈ 1.85 GV V0 = 5.5 to 15 GV o o o o K = 3.9 – 1.65 Φ1.3 GHz ≈ 20 Φ ≈ 28 Φ ≈ 22 Φ = 0 SASE1/2 K = 9 – 4 V0, 3.9 GHz ≈ 25 MV SASE3 o Φ1.3 GHz ≈ 190 4 Modules 12 Modules 80 Modules 300 kW 1 Module A2 A3 A4 A5 A6 A25 A1 AH1 SASE1 0.24 kW 5 kW 9 kW 300 kW Gun LH, Dogleg, BC0 BC1 BC2 Collimation 300 kW 1.3 GHz R56 = -150 to -30 R56 = -120 to -50 R56 = -80 to -20 R56 = 0 6 MeV 130 MeV 600 MeV 2.4 GeV 6 to 17.5 GeV
¢ Superconducting linac with 97 1.3 GHz superconducting modules ¢ 10 Hz pulsed mode with 600 µs flat-top, 2700 bunches/pulse ¢ Variation of bunch charges between 20-1000 pC foreseen to vary final pulse length ¢ Fast distribution of bunches into beam distribution lines
IPAC ‘17, 15.5.2017 Winni Decking, DESY Commissioning of the European XFEL Accelerator
Commissioning Plan 7 Strategy: get as many systems in the game as soon as possible 12/16 Start: Cooldown 01/17 Injector at 130 MeV (3 RF stations) 01/17 L1 commissioning (+1 RF station) 02/17 L2 commissioning (+3 RF stations) 02-04/17 L3 commissioning (+15 RF stations) 05/17 Beam through SASE1 & SASE3 undulator sections End 05/17 Milestone “First Lasing Possible” 06-08/17 Commission SASE1 photon beamline and experiment Consolidate FEL operation at 8-10 keV photon energy 09/17 First user experiments (total 800 hours) 2018 Continue facility commissioning + 2000 user hours 2019 Routine operation with 6 experiments + 4000 user hours
IPAC ‘17, 15.5.2017 Winni Decking, DESY Commissioning of the European XFEL Accelerator
Final E-beam parameters 8 Quantity Value electron energy 8/12.5/14/17.5 GeV macro pulse repetition rate 10 Hz RF pulse length (flat top) 600 µs # of bunches/second 27000 bunch charge 0.02 – 1 nC electron bunch length after compression (FWHM) 2 – 180 fs normalized slice emittance * 0.4 - 1.0 mm mrad beam power 500 kW simultaneously operated SASE undulators 3
* normalized emittance:
IPAC ‘17, 15.5.2017 Winni Decking, DESY Commissioning of the European XFEL Accelerator
Commissioning E-beam parameters 9 Quantity Value electron energy 8/12.5/14/17.5 GeV macro pulse repetition rate 10 Hz RF pulse length (flat top) 600 µs # of bunches/second 27000600 bunch charge 0.02 – 1 nC 0.5 nC electron bunch length after compression (FWHM) 2 – 180 fs 90 fs normalized slice emittance 0.4 - 1.0 mm mrad beam power 500 kW 5 kW simultaneously operated SASE undulators 3 1
IPAC ‘17, 15.5.2017 Winni Decking, DESY Commissioning of the European XFEL Accelerator
Injector in Operation 2015/2016 10
Dump Transverse Deflecting Structure Spectrometer Diagnostic Section Laser Heater 3.9 GHz Module 1.3 GHz Module Gun
¢ Photoinjector conditioned and characterized at PITZ, DESY-Zeuthen Y. Renier, TUPIK051/TUPIK052 ¢ Injector cool-down 12/2015 ¢ First Beam on 18/12/2015- commissioning till Q2/2016 ¢ Full bunch train length (27000 bunches/s) reached for 20pC-1000pC bunch charges ¢ Photocathode laser (Yb:YAG laser from Max-Born Institute Berlin 257 nm ≤ 4 µJ; 3 ps) with excellent up-time C. Maiano, MOPVA058/MOPVA059 ¢ 3.9 GHz system operational from day 2 P. Pierini, MOPVA067
¢ Laser heater commissioned (but not in routine operation) M. Hamberg, WEPAB024
IPAC ‘17, 15.5.2017 Winni Decking, DESY Commissioning of the European XFEL Accelerator
Emittance Measurements Scheme of the XFEL injectorProjected diagnostic emittance section along bunch train
Emittance optimization mainly at 500 pC and reduced gun gradient ( ≈ 52 MV/m) Design Achieved Normalized proj. > 1.5 1.2 Optics mismatch along bunchemittance train [mm mrad] Normalized slice 0.6 0.6 emittance [mm mrad]
¢ Fast kickers kick single bunches out of the trains to off-axis screens ¢ “Semi-parasitic” diagnostics during beam delivery ¢ Together with transverse deflecting system also used for slice diagnostics
IPAC ‘17, 15.5.2017 Winni Decking, DESY Commissioning of the European XFEL Accelerator
Emittance Measurements along Bunch Trains Scheme of the XFEL injectorProjected diagnostic emittance section along bunch train
Optics mismatch along bunch train
Up to a factor 2 with respect to design beta functions
Matched to design optics
¢ Fast kickers kick single bunches out of the trains to off-axis screens ¢ Variations along the train can be ¢ “Semi-parasitic” diagnostics during monitored beam delivery ¢ Corrections to provide uniform ¢ Together with transverse deflecting conditions along train B. Beutner, WEPAB013 system also used for slice diagnostics M. Scholz, MOPAB047
IPAC ‘17, 15.5.2017 Winni Decking, DESY View AlongCommissioning the 1 of km the European Long XFEL Accelerator Superconducting Accelerator View along the linear accelerator
IPAC ‘17, 15.5.2017 Winni Decking, DESY Commissioning of the European XFEL Accelerator
Overview of XFEL Cryogenic Equipment 14
Cryo Plant ¢ Cryo plant with cold compressors and extended distribution system ¢ Cooling capacity: 2K : >1.9 kW 5/8K : 4 kW 40/80K : 24 kW ¢ Linac is one 1.5 km long cryo-string
Cold Compressors He Distribution Linac
IPAC ‘17, 15.5.2017 Winni Decking, DESY Commissioning of the European XFEL Accelerator
First Cooldown of XFEL Linac (>300 t) 15 T [K] Temperature at 9 positions along the linac versus time 300 Cooldown with one coldbox
Start asymmetrical operation of two cold boxes to speed up cooldown 200
Fast cooldown at temperatures 100 Recovery of cold return below liquid nitrogen (no more flows in cold boxes to thermal stress) enhance cryogenic capacity Reached 4K 0 10.12.2016 27.12.2016 No cold leaks !
IPAC ‘17, 15.5.2017 Winni Decking, DESY Commissioning of the European XFEL Accelerator
Pressure Stability in 2K Circuit 16 ¢ Requirement on 2K pressure stability: 2% peak from LLRF requirements (cavity detuning) ¢ Tedious adjustment of regulation loops ¢ Inner-system heaters to counteract dynamic processes
2K pressure [mbar]
30.9
2K pressure 30.6 ± 1%
30.3 Sudden shutdownLinac pressure of (2K) 18 RF stations
7 hours
IPAC ‘17, 15.5.2017 Winni Decking, DESY Commissioning of the European XFEL Accelerator Linac Commissioning started from
Accelerator Control Room (BKR) 17
With help from:
IPAC ‘17, 15.5.2017 Winni Decking, DESY Commissioning of the European XFEL Accelerator
XFEL RF System 18
Cryo Plant Cryo Plant
CM1 (8 cav.) CM2 (8 cav.) CM3 (8 cav.) CM4 (8cav.)
KLYSTRON
¢ HV Modulators in surface hall ¢ Connected to pulse transformer via up to 2km long pulse cables Klystron and modulator below module
IPAC ‘17, 15.5.2017 Winni Decking, DESY Commissioning of the European XFEL Accelerator
XFEL LLRF System 19
CM1 (8 cav.) CM2 (8 cav.) CM3 (8 cav.) CM4 (8cav.)
KLYSTRON
LLRF master LLRF slave
Drift compensation
Reference synchr. + distr.
Clocks + local oscillator
Main controller crate (MicroTCA)
Piezo* LLRF Power supplies LLRF master slave * not installed yet IPAC ‘17, 15.5.2017 Winni Decking, DESY Commissioning of the European XFEL Accelerator
MicroTCA.4 for Accelerator Controls
¢ MicroTCA.4-based components used as standard hardware platform (LLRF, Diagnostics, Vacuum, HPRF, Magnets, Timing, ….) ¢ About 200 systems installed, serving more than 7.000.000 control parameters ¢ Operational from day 1 of deployment
¢ Key benefits: ° Fully automated and standardized installation procedure allows rapid deployment and recovery ° Enhanced remote management via IPMI and Ethernet allow for simplified maintenance ° Extended monitoring and management of module ensure reliable crate operation
T. Walter, THOAB2
IPAC ‘17, 15.5.2017 Winni Decking, DESY Commissioning of the European XFEL Accelerator
J. Branlard, THOAA3 LLRF commissioning 21 ¢ Commissioning milestones ° Cold coupler conditioning (when needed) RF ONLY ° Frequency tuning (from parking position) ° Coupler tuning (target QL) ° Power-based gradient calibration (coarse) ° Closed-loop operation (feedback, learning feedforward) ° Establish beam transport (0.5 nC, 30 bunches) BEAM ° Cavity phasing (moving waveguide phase shifters) REQUIRIED ° Beam-based gradient calibration (fine)
¢ Estimated schedule ° Injector (gun, A1, AH1) 2 weeks Operation of RF stations ° L1 (1 RF station) 2 weeks time shifted “off-beam” ° L2 (3 RF stations) 2 weeks allowed for parallel beam commissioning in L3 ° L3 (15 RF stations) 2 months IPAC ‘17, 15.5.2017 Winni Decking, DESY Commissioning of the European XFEL Accelerator
Energy Reach of European XFEL Modules 22
Design: 17.5 GeV
L1 L2 L3
¢ Average accelerating gradient after module test and waveguide tailoring ‹ 26 MV/m, (design 23.5 MV/m) ¢ Some additional gradient “loss” due to tunnel waveguide distribution ¢ Excess energy reach will enhance operation reliability
IPAC ‘17, 15.5.2017 Winni Decking, DESY Commissioning of the European XFEL Accelerator
Operating Gradients used so far 23
Design: 17.5 GeV
12 GeV
exp. status of 10.04.17
L1 L2 L3
¢ After initial commissioning design gradient almost reached ¢ Operation of RF stations “off beam” allows final commissioning of single stations parallel to XFEL operation
IPAC ‘17, 15.5.2017 Winni Decking, DESY Commissioning of the European XFEL Accelerator
LLRF in operation 24
in operation
dito. but shifted off beam
off
¢ 20 out of 25 RF stations are commissioned ¢ Handed over to operations and controlled via FSM ¢ Inner loop RF stability <0.01 deg, < 0.01% ¢ Preliminary measurements of beam energy jitter ≈ 10 -4
IPAC ‘17, 15.5.2017 Winni Decking, DESY First BunchCommissioning Compressor of the European XFEL Accelerator Chicane (BC0)
IPAC ‘17, 15.5.2017 Winni Decking, DESY View AlongCommissioning the 1 of km the European Long XFEL Accelerator Superconducting Accelerator View along the linear accelerator
IPAC ‘17, 15.5.2017 Winni Decking, DESY Commissioning of the European XFEL Accelerator Transfer Lines at the End of the Main Linac Tunnel (XTL)
IPAC ‘17, 15.5.2017 Winni Decking, DESY Commissioning of the European XFEL Accelerator
Beamline Commissioning Progress 28
L1 L2 L3
0m 30m 230m 480m 1430m 2100m 3100m
13/01 * 15/01 @ 130 MeV * Beam permission on 13/01 19/01 @ 600 MeV 02/02 @ 600 MeV 22/02 @ 2.5 GeV 25/02 @ 2.5 GeV 19/03 @ 6 GeV 08/04 @ 12 GeV
IPAC ‘17, 15.5.2017 Winni Decking, DESY Commissioning of the European XFEL Accelerator
Achieved E-beam parameters 29 Quantity Target Achieved electron energy 14 GeV 12 GeV % macro pulse repetition rate 10 Hz 10 Hz RF pulse length (flat top) 600 µs 600 µs # bunches/ second 600 300 $ bunch charge 0.5 nC 0.1, 0.5 nC electron bunch length after compression 90 fs 90 fs (FWHM) Normalized slice emittance 1 mm mrad 0.6 mm mrad $ beam power 4.2 kW 1.8 kW
$: in the injector
% Initial commissioning at reduced gradients & 3 more stations ready $ Machine protection system ‘soft’ limit
IPAC ‘17, 15.5.2017 Winni Decking, DESY Commissioning of the European XFEL Accelerator
Subsytems: Example BPM Resolution 30
10 µm Button BPM d=78mm ≈ 5 µm Button BPM d=40mm ≈ 2 µm
Re-entrant BPM d=78mm ≈ 2 µm 1 µm Cavity BPM d=40mm < 1 µm
0 m Distance along accelerator 2100 m
Correlations subtracted
“All systems perform better than specification” D. Lipka, MOPAB043
IPAC ‘17, 15.5.2017 Winni Decking, DESY Commissioning of the European XFEL Accelerator
Open Question: Transverse Beam Distribution 31
L1 L2 L3
0m 30m 230m 480m 1430m 2100m 3100m
¢ Images of scintillating screens along the beam line ¢ Structure is present even after acceleration and compression ¢ Can be observed in simulations (non-linear space charge effect), but should be more sensitive to phase-advance …
IPAC ‘17, 15.5.2017 Winni Decking, DESY BacksideCommissioning view of the European XFEL Accelerator Undulator Section with climate enclosure in the back
IPAC ‘17, 15.5.2017 Winni Decking, DESY Commissioning of the European XFEL Accelerator
Beamline Commissioning Progress 33
L1 L2 L3
0m 30m 230m 480m 1430m 2100m 3100m
13/01 * 15/01 @ 130 MeV * Beam permission on 13/01 19/01 @ 600 MeV 02/02 @ 600 MeV 22/02 @ 2.5 GeV 27/04 Beam spot before dump 25/02 @ 2.5 GeV 19/03 @ 6 GeV 08/04 @ 12 GeV
27/04 *
* Beam permission on 26/04
IPAC ‘17, 15.5.2017 Winni Decking, DESY Commissioning of the European XFEL Accelerator
Undulators passed with no steering 34
+4 Horizontal trajectory [mm] 0 -4
225 m resp. 140 m of 8x8 mm beam tube +4 Vertical trajectory [mm] 0 -4
0 1000 2000 3000 s [m]
IPAC ‘17, 15.5.2017 Winni Decking, DESY Commissioning of the European XFEL Accelerator
‘First lasing possible’ 29.04.2017 35 ¢ Closed all (35) SASE undulators to 11 mm gap (K=3.5) ¢ Observed spontaneous radiation on scintillator screen about 170 m downstream of undulator ¢ Radiation fills complete screen and is visible as increase of intensity only
Electron beam on
IPAC ‘17, 15.5.2017 Winni Decking, DESY Commissioning of the European XFEL Accelerator First signal from FEL radiation
02.05.17-03.05.17 36 ¢ low energy 6.4 GeV working point for beam based alignment ¢no undulator beam based alignment yet, no laser heater
some tweaking of compression and trajectory
E = 6.4 GeV K = 3.5 1.3 keV
IPAC ‘17, 15.5.2017 Winni Decking, DESY Commissioning of the European XFEL Accelerator
Commissioning Timeline 37 12/16 Cooldown 01/17 Injector at 130 MeV 01/17 L1 commissioning 02/17 L2 commissioning 02-04/17 L3 commissioning 04 /17 Beam through SASE1 & SASE3 undulator sections End 04 /17 Milestone “First Lasing Possible” 2-3/5/17 FEL radiation observed 05-08/17 Commission SASE1 photon beamline and experiment Consolidate FEL operation at 8-10 keV photon energy 09/17 First user experiments (total 800 hours) 2018 Continue facility commissioning + 2000 user hours 2019 Routine operation with 6 experiments + 4000 user hours
IPAC ‘17, 15.5.2017 Winni Decking, DESY Options for the Euroepan XFEL General Assembly of the European XFEL Accelerator Consortium 04.05.2017
THANK YOU TO ALL CONTRIBUTORS TO THE EUROPEAN XFEL
Ringberg Workshop on Science with FELs, 07.03.2012 Winfried Decking, DESY