Fi L i b l 7 W l hFirst Lasing below 7nm Wavelength at FLASH/DESY, Hamburg
Jörg Rossbach
University of Hamburg & DESY, Germany
- For the FLASH Team -
email: [email protected]
FLASH: The first FEL user facility for the soft X-ray regime
FLASH
J. Rossbach: First Lasing below 7nm at FLASH/DESY 225 August 2008
FLASH: over-all layout
RF gun CollimatorAccelerating StructuresDiagnosticsRF gun
LaserBunch
Compressor
UndulatorsCollimator
Bunch Compressor
Accelerating StructuresDiagnostics
FEL
260 m
Bypass5 MeV 130 MeV 470 MeV 1000 MeV Diagnostics
J. Rossbach: First Lasing below 7nm at FLASH/DESY 325 August 2008
FLASH/European XFEL technologyFLASH and European XFEL are basically very similar machines:
UndulatorCollimatorLaser
BC2 Main acceleratorBoosterInjector BC1 Exp.
RF gun
FLASH: 130MeV 470MeV 1.0GeV 6.5nmXFEL: 500MeV 2.0 GeV 17.5GeV 0.1nm
3rd harm. RF
Para. FLASH XFELεx,y 2 μm 1.4 μm
Based on same SRF technologyOnly small differences in beam parameters (except E) Almost all tests can be carried out at FLASH!
Ipeak 2.5 kA 5 kAfrep 1 (9)MHz 5 MHzQ 1 nC 1 nC
Strategy towards 1 Å: Proceed in stages (starting 1994): TTF1 (100 nm) FLASH (6 5 nm) XFEL (0 1 nm)
E 1 GeV 17.5 GeVRF 1.3/3.9GHz 1.3/3.9GHzΔt 800μs 650μs
TTF1 (100 nm), FLASH (6.5 nm), XFEL (0.1 nm).Go for superconducting accelerator:
excellent stabilitylarge number of bunches per sec.
J. Rossbach: First Lasing below 7nm at FLASH/DESY 425 August 2008
Δx/Δy 5μm 3μmg
several beamlinesmulti-user facility
Run FLASH as a user facility as soon as possible.
Progress towards short wavelengths
1000Lasing at 6.5 nm 10/2007
800
gy (M
eV)
Lasing at 13 nm 4/2006, Saturation 8/2006
600
eam
Ene
rg
Lasing at 32 nm 1/2005
Lasing at 25 nm 12/2005 2
2 12 2u
phK⎛ ⎞λλ = +⎜ ⎟γ ⎝ ⎠
FEL at TTF 1 (upgraded into FLASH 2003)Proof-of-Principle for SASE in the VUVFirst Lasing 2/2000 Saturation 9/2001
400
Ele
ctro
n B
e Lasing at 32 nm 1/2005
First Lasing 2/2000, Saturation 9/2001
20 40 60 80 100 120 140 160 180
200
E
400 800
J. Rossbach: First Lasing below 7nm at FLASH/DESY 525 August 2008
FEL Wavelength (nm)
Acc. Module 6 installed 1 GeV/6.5 nm
AC
C2
AC
C4
AC
C5
AC
C3
AC
C6
TTF1
TTF1
TTF1
J. Rossbach: First Lasing below 7nm at FLASH/DESY 625 August 2008
Lasing at 6.5 nm
Lasing at smallest achievable wavelength of 6.5 nm reached in October 5th, 2007FLASH design value achieved(defined 1994, presented on FEL95)( , p )
J. Rossbach: First Lasing below 7nm at FLASH/DESY 725 August 2008
Lasing at 7.1 nm
Spectral distribution of a single FEL pulse at 7.1 nm
7 1 nm beam on Ce:YAG
2.5 mm
7.1 nm beam on Ce:YAG screen at 20 m distance
Pulse energy: ~5 µJPulse energy: ~5 µJPulse duration: <10 fs
J. Rossbach: First Lasing below 7nm at FLASH/DESY 825 August 2008
Double slit diffraction patterns at 7.1 nm (0.15mm slit separation)Wave front: E. Ploenjes TUBAU03
Preliminary Radiation Properties @ 6.9 nmLasing at 6.5 nm and 6.9 nm,7 nm delivered to userssingle shot spectra show a small
Gain curve @ 6.9 nm (preliminary)
number of modes → preliminary estimated pulse length: 5-10 fsoperation stability acceptable for user, b t t t ti f tbut not yet satisfactory
6.75 6.8 6.85 6.9 6.96 7.0 7.05 7.1
J. Rossbach: First Lasing below 7nm at FLASH/DESY 925 August 2008
wavelength (nm)
Harmonics
2nd harmonics 3rd harmonics
J. Rossbach: First Lasing below 7nm at FLASH/DESY 1025 August 2008
Performance at 7nm/train of 10 bunches
J. Rossbach: First Lasing below 7nm at FLASH/DESY 1125 August 2008Operation performance:K. Honkavaara: FRAAU01
Lasing with long bunch trains
800 bunches 685 MeV 13 4 nm
Lasing with trains of up to 800 bunches, >10 µJ/pulse achievedMachine Protection System: fully operational, with minor constraints
100 bunches 960 MeV 7 nm800 bunches, 685 MeV, 13.4 nm<electron beam power> : 2.7 kW
<photon power>: 56 mW
100 bunches, 960 MeV, 7 nm<photon power>: 14 mW
μJp p
single bunch radiation energyμJ
40
μ
30
max.20
average
7.0 7.1 λ/nm
J. Rossbach: First Lasing below 7nm at FLASH/DESY 1225 August 2008 single bunch
Peak brillianceBrilliance: 24 x x y yθ θπ
Φ=Σ Σ Σ Σ
with etc.
For transv. coherent source:
2 2, ,x x ph x eσ σΣ = +
λ4rad
x x y yθ θλ
πΣ Σ = Σ Σ =
4B Φ
Spectral flux:
2FELrad
Bλ
=
Spectral flux: #photons
(pulse duration) (spectral width)Φ =
⋅
J. Rossbach: First Lasing below 7nm at FLASH/DESY 1325 August 2008
Peak brilliance#photons
(pulse duration) (spectral width)Φ =
⋅
# photons: Single pulse radiation energy spectral width (0.1% units): Avg. spectrumpulse duration: 2 (FWHM spectral width of single shot spikes) radT π≅
p g p gy
Cross check:1. Get coherence length from measured gain length
- don‘t use width of avg. spectrum for cross check:g pspectral widening due to energy chirp within bunch !
2. Count # long. modes M from single shot spectraOR extract M from fluctuation of pulse energy0.8 (b)
σ = 72% - OR extract M from fluctuation of pulse energy(should be the same !)
3. Cross check with numerical simulation 0.2
0.4
0.6
0.8 (b)
p(E
rad)
= 72%M = 1.9
rad cohT M τ≅ ⋅M Roehrs:
J. Rossbach: First Lasing below 7nm at FLASH/DESY 1425 August 2008NOTE 1: Time domain measuments under way ! NOTE 2: This all assumes flat top bunch profile !
& measurements of electron bunch profileFluctuation of pulse energy due to start up from noise @ 13.7nm
0 1 2 3 4 50.0
Erad
/<Erad
>
M. Roehrs: MOPPH049
U. Frühling: THDAU01
FLASH @ FEL08
C.H.Boulware THAAU05 Electron beam results from PITZR. Spesyvtsev TUPPH037 Slice emittance measuments at PITZ/ZeuthenJ. Roensch TUPPH038 Long. phase space measurement at PITZY Ivanisenko TUPPH079 Slice emittance measurements at PITZ
InjectorY. Ivanisenko TUPPH079 Slice emittance measurements at PITZS. Schreiber FRAAU05 Cathode issues at the FLASH rf gun
K. Honkavaara FRAAU01 Status of FLASHB. Faatz TUPPH063 Radiation damage of undulatorElectrons gM. Roehrs MOPPH049 3D electron bunch measurement B. A. Winter TUPPH066 Synchronization systemB. Schmidt TUPPH068 Observation of coherent micro-bunchingF Loehl THBAU02 Demonstration of 40 fs synchronizationF. Loehl THBAU02 Demonstration of 40 fs synchronizationS. Khan THBAU04 Optical Replica ExperimentS. Khan TUPPH072 sFLASH: Seeding FLASH @ 30nmR.Tarkeshian TUPPH051 Temporal overlap for seedingV Miltchev TUPPH003 HHG seedingV. Miltchev TUPPH003 HHG seeding
E. Ploenjes TUBAU03 Wavefront measurments B. Faatz TUPPH004 Polarization from crossed-planar undulatorM. Kuhlmann TUPPH069 High-resolution online-spectrometer
Photons
J. Rossbach: First Lasing below 7nm at FLASH/DESY 1525 August 2008
M. Kuhlmann TUPPH069 High resolution online spectrometerJ. Zemella TUPPH070 Timing of optical pulse trainsU. Fruehling THDAU01 Time domain measurement of pulse lengthChr. Gutt THDAU02 Resonant magnetic scattering
1st Round of User Experiments ended 3/2007
18 projects received beamtime18 projects received beamtime>200 scientists 60 institutes, 11 countries
> 25 publications already, many more to comey
4 PRL 6 APL 1 Nature1 Nature, 1 Nature Physics 1 Nature Photonics
J. Rossbach: First Lasing below 7nm at FLASH/DESY 1625 August 2008
…See, e.g.,http://hasylab.desy.de/facilities/flash/publications
2nd Round of User Experiments
J. Rossbach: First Lasing below 7nm at FLASH/DESY 1725 August 2008
New infrared undulator
Located downstream of FEL Improved coherent THz diagnosticsFIR pulse naturally synchronized to FEL pulseFIR transported into e p hall for p mp probeFIR transported into exp. hall for pump-probeStatus: - FIR pulse observed,
-overlap FIR and FEL pulses detectedU. FruehlingTHDAU01
J. Rossbach: First Lasing below 7nm at FLASH/DESY 1825 August 2008
Frequency domain diagnostics with THz rad.
Single shot spectrum of coherent infrared radiation exhibits structure in the longitudinal density modulation < 5 μm !! Need single shot spectrometer for wide IR bandwidthNeed single shot spectrometer for wide IR bandwidth
Recent development at DESY/UHH THz signal also used for long. FB
Size of lasing spike
Pyro electric line detector from individual pyros+ 30 channels + room temperature+ no window, works in vacuum
J. Rossbach: First Lasing below 7nm at FLASH/DESY 1925 August 2008
Substructure inside spike
B. SchmidtTUPPH068
High Harmonic Laser Seeding at 30nm (“sFLASH”)
LINAC SASE FEL
J. Rossbach: First Lasing below 7nm at FLASH/DESY 2025 August 2008S. Khan TUPPH072
FLASH II: Proposal for a 2nd FEL beamline
J. Rossbach: First Lasing below 7nm at FLASH/DESY 2125 August 2008
More room for usersQuasi-simultaneous operation with 2 wavelengths
Outlook
••••2010 Installation 7th acc. Module ~1.2 GeV/<5nm
operation with 3rd harmonic cavitylong bunch train operation
2009•••now
variable pulse and energy patternsbeam stability (LLRF and beam based feedbacks)Seeding (sFLASH)
d
2008
•••• 22ndnd round of user experiments startsround of user experiments starts
Proposal for a 2nd FEL beamline
2007
•••
shutdown: installation 6shutdown: installation 6thth modulemodule1 GeV beam energy: lasing at 6.5 nm1 GeV beam energy: lasing at 6.5 nm
2007 ••• saturation at 13 nm achievedsaturation at 13 nm achieved
J. Rossbach: First Lasing below 7nm at FLASH/DESY 2225 August 20082006
••
first lasing at 13 nmfirst lasing at 13 nm
Summary
Lasing at 6.5 nm demonstrated.
Considerable user experience gained.
No show stopper visible.
Ambitious upgrade program launchedAmbitious upgrade program launched.
Continuous progress towards XFELs.Continuous progress towards XFELs.
J. Rossbach: First Lasing below 7nm at FLASH/DESY 2325 August 2008