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-J.Bähr, PITZ, Technisches Seminar, 3.Juli, 2007 1
PITZ Shutdown 2007
J.Bähr
PITZ, DESY
Technisches Seminar 3.Juli 2007
-J.Bähr, PITZ, Technisches Seminar, 3.Juli, 2007 2
Outline• Outline1. Introduction2. Explanations: PITZ, XFEL, Emittance,…3. PITZ more detailed4. Shutdown: Why and what5. Manpower and coordination6. Outlook
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-J.Bähr, PITZ, Technisches Seminar, 3.Juli, 2007 3
1.Introduction- A long shutdown at PITZ is planned starting
from 20/08/2007 until beginning of November- Most modules of the vacuum beamline will be
dismounted and re-mounted in a new scheme - The Conditioning Test Stand (CTS) will be
mounted in the tunnel bearing gun 4.1- The rf system 1 will be re-organized for the
use of a 10 MW klystron- Many further tasks
-J.Bähr, PITZ, Technisches Seminar, 3.Juli, 2007 4
2. Explanations: PITZ, XFEL, Emittance …
• What is that:• PITZ,XFEL,FLASH,emittance, laser, SASE,
space charge, electron gun…• What is the connection between:
– FEL and emittance– Emittance and space charge– A gun and a TV tube– PITZ and the XFEL,FLASH– …
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-J.Bähr, PITZ, Technisches Seminar, 3.Juli, 2007 5
Setup PITZ1.6 completed !transverseemittance
gunboosterquads
longitudinalphase space masks
Gun
-J.Bähr, PITZ, Technisches Seminar, 3.Juli, 2007 6
PITZ• PITZ:“ Photo injector
Test Facility“• Test and optimize
electron sources forFELs: FLASH,XFEL
• X-FEL: European X-ray FEL project
• e-gun
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-J.Bähr, PITZ, Technisches Seminar, 3.Juli, 2007 7
„FEL-Microscope“• FEL: „Free Electron Laser“:
„Microscope“• Motivation!!!• Resolution R:
about wavelength R~ λfor microscopes
• The higher the beamenergy , the smaller
• better) the resolution R of the „microscope“
• c=νλ ,E=hv E=hc/λλ~1/E
• Resolution ~ λ~1/E
• Resolution of microscopes
Atoms~1 Angstr.3 GeVXFEL
Molecules~7nm500 MeV/200eV
FLASH
Big molecules
~O(10 nm)Magnifica-tion: 10**5
~70 keVElectronmicro-scope
Biologiccell
1 µm1 eV (light)Light micro-scope
ObjectResolutionEnergyElectron/photon
Device
-J.Bähr, PITZ, Technisches Seminar, 3.Juli, 2007 8
FEL• FEL: Free electron laser :SASE principle
e-GunLinear accelerator Undulator: Magnetic structure
E-beam
Light/electro-magnradiation
Beam dump
SASE principle:„Self amplified radiation by stimulated emission“
PITZ
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-J.Bähr, PITZ, Technisches Seminar, 3.Juli, 2007 9
The gun
• The gun:– Laser input port– Cathode– rf coupler– Solenoid magnets– Resonator– Vacuum tubes
-J.Bähr, PITZ, Technisches Seminar, 3.Juli, 2007 10
Comparison of an e-gun and a TV tubeGun-TV
TV Gun
Bild Bild
Cathode thermal Photo effect acceleration Electro static Rf Voltage accel. ~4kV ~6 MV Electron energy ~4 keV
W=Q*U=1e*4kV 6 MeV
El. Field strength E=U/d=4kV/0.2m=20kV/m 60MV/m Deflection Electro static Dipole magnet (if
wanted visualisation TV screen + eye Flourescence screen
+ TV camera (no access)
radiation X-rays X-rays Create image deflection Move laser spot
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-J.Bähr, PITZ, Technisches Seminar, 3.Juli, 2007 11
Comparison between TV tube and an electron gun
Focusing using solenoids
-J.Bähr, PITZ, Technisches Seminar, 3.Juli, 2007 12
Mis-unerstanding• If one does not consider the motivation and
the context one could assume:
• PITZ is a not effective designed, rather hugebuilt TV tube with enormous runningparameters, where one has no access and the TV program is not interesting for typicalcitizens and difficult to regard and onlyremotely because there is no accesspossible. The screen size is much too low(about 2“).
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-J.Bähr, PITZ, Technisches Seminar, 3.Juli, 2007 13
FLASH• FLASH: Free electron LASer in Hamburg• (earlier TTF)
Brilliance: Photons in solid angle and per area unit pro wavelength intervall
Gun
LINAC Undulator
PITZ
-J.Bähr, PITZ, Technisches Seminar, 3.Juli, 2007 14
Laser• LASER: „Light Emission by Stimulated Emission of
Radiation“• Characteristics of laser light:
1. High energy density :“parallel“ ray of light instead of divergent bundle
2. Coherence: phase relations between parts of the light ray: possibility of interference Holography
3. Monochromatic light: only one wavelength (visible-invisible)
Resolution R~ λ~1/E
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-J.Bähr, PITZ, Technisches Seminar, 3.Juli, 2007 15
Electromagnetic spectrum
Resolution R~ λ~1/E
-J.Bähr, PITZ, Technisches Seminar, 3.Juli, 2007 16
Emittance• Emittance :• Characteristic of electron
beam• For FEL small emittance
necessary!!!• Optimization of e-gun:
Minimalization of transverseemittance
• - EMSY: Emittancemeasurement system
• Emittance cannot beimproved after the source!!
• Emittance
• Divergent electron beam• ε : diameter * angle• ε = d * α in mm *mrad• Example : • Beam diameter : 1mm• Divergence α =0.05 °=
1mrad• ε = 1mm mrad
d
α
-J.Bähr, PITZ, Technisches Seminar, 3.Juli, 2007 18
Emittance1. What emittance has been measured by
PITZ?2. What are the goals?3. World record?
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-J.Bähr, PITZ, Technisches Seminar, 3.Juli, 2007 19
εx,y ~ (e- beam size) • (e- beam angular divergence)
Why injector so important ?What is emittance ?
Why it must be small ?
εn = 1 mm mrad
length of the undulator
εn = 2 mm mrad
εn = 4 mm mrad
Q = 1 nCoutp
ut p
eak
pow
er o
f th
e VU
V-FE
L @
6.4
nm
(G
W)
path length in the undulator (m)
VUV-FEL
peak power
• smaller emittance ⇒ new horizons: shorter wavelength,higher repetition rate
• XFEL goal: 0.9 mm mrad@injector = 1.4 mm mrad@undulator
εn = 1 mm mrad
outp
utpe
akpo
wer
of t
heXF
EL S
ASE
2@
0.1
nm
(GW
)
path length in the undulator (m)
εn = 2 mm mrad
εn = 3 mm mrad
peak current: 5 kAenergy spread: 2.5 MeV
XFEL
absolute numbers
-J.Bähr, PITZ, Technisches Seminar, 3.Juli, 2007 20
Emittance• Emittance results:
0.8
1.2
1.6
2.0
2.4
2.8
3.2
320 322 324 326 328 330Imain, A
norm
. em
ittan
ce /
mm
mra
d ExEySQRT(Ex*Ey)measured @ PITZ:
p = 5.2 MeV/c
Q = 1 nCΦ = Φm
Ibuck = Imain * 0.075(100% rms projected emittance)
Results fromPITZ1: 2005 (Gun1) VUV-FEL13nm
XFEL
WR
VUV-FEL 6nm
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-J.Bähr, PITZ, Technisches Seminar, 3.Juli, 2007 21
Emittance• Results 2006: Gun3.1
0,5
1,0
1,5
2,0
2,5
3,0
278 280 282 284 286 288 290Imain [A]
norm
. pro
ject
ed e
mitt
ance
[mm
mra
d]
Emitt(x)Emitt(y)ASTRA simulation
-J.Bähr, PITZ, Technisches Seminar, 3.Juli, 2007 22
Setup PITZ1.6 completed !transverseemittance
gunboosterquads
longitudinalphase space masks
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-J.Bähr, PITZ, Technisches Seminar, 3.Juli, 2007 23
Present layout of PITZ
-J.Bähr, PITZ, Technisches Seminar, 3.Juli, 2007 24
PITZ• Simplified scheme
DDC
Rf-coupler
rf
Laser beam
E-gunDiagnostics
Booster cavityDiagnosticsBeam dump
Not in scale!!
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-J.Bähr, PITZ, Technisches Seminar, 3.Juli, 2007 25
PITZ diagnostics
EMSYEmittance
Streak cameraBunch length
Spectrometer, dipole magnet
Beam energy
Faraday cup,ICT (Integratingcurrent transformer)
Charge
Screen station (TV),wire scanner
Beam:Profile, diameterDeviceMeasure
-J.Bähr, PITZ, Technisches Seminar, 3.Juli, 2007 26
PITZ : Auxiliary system• Auxiliary systems• Vacuum• Photocathode laser and laser beamline• Cooling and climatization• Rf system: 2 Klystrons 5-10 MW,
modulators,…• Electronics• Controls
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-J.Bähr, PITZ, Technisches Seminar, 3.Juli, 2007 27
PITZ history
PITZ history Year Gun Project
stage Remarks
1999 Decision directorate 2000 Construction 2001 Gun2 PITZ1 Commissioning 13/01/2002 Gun2 PITZ1 1st photoelectrons 2003 Gun2 PITZ1 Nov.:Gun2: HH 2004 Gun1 Dec.: upgrad 2005 Gun1 PITZ1.5 Upgrade, booster,
10MW klystron 2006 Gun1 PITZ1.6 57MW/m Gun3.1 Conditioning,
Characterization, Gun3.1 HH
2007 Gun3.2 PITZ1.6 Cond.,Charact. 2007 PITZ1.7
-J.Bähr, PITZ, Technisches Seminar, 3.Juli, 2007 28
PITZ : The shutdown• Why?• Insert HEDA1: High energy
dispersive arm• Move booster downstream
(higher gun gradient)• Space for new CDS booster
(2008)• Minor change of sequence
of diagnostics elements• Prepare for PITZ 2
beamline 2008• Reconstruction of low
energy section (New DDC,..)
• Further tasks• Extension of laser hutch• New laser• New klystron 10MW for rf1• New technical interlock• Many small tasks
– TV system– Exchange YAG screen– EMSYs…– …
• PITZ1.6 PITZ1.7
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-J.Bähr, PITZ, Technisches Seminar, 3.Juli, 2007 29
PITZ : The shutdown• Major changes in beam
line
GunBooster
Dipole Diagnostics Beam dump
Beam dump
Reconstructed low energy section
HEDA1
New HEDA1
HE diagnostics
modified
PITZ1.6
PITZ1.7
-J.Bähr, PITZ, Technisches Seminar, 3.Juli, 2007 30
PITZ 1.6, PITZ 1.7PITZ 1.6
PITZ 1.7
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-J.Bähr, PITZ, Technisches Seminar, 3.Juli, 2007 31
PITZ : The shutdown• Vacuum work:
– Dismount modules– CTS: Conditioning test stand:
Gun 4.1– Mount modules– Mount HEDA1– Reconstruction Low energy
section:• DDC• Dipole…
– ……– Parallel work of two teams New dipole HEDA1 – 180 grad
-J.Bähr, PITZ, Technisches Seminar, 3.Juli, 2007 32
PITZ : The shutdown• RF group:• Reconstruction rf system1• Exchange klystron 5MW 10MW• Waveguides to CTS• Investigation of T-combiner• ………
• Electronics:• New technical interlock• Connect all new/moved components, tests• ……….
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-J.Bähr, PITZ, Technisches Seminar, 3.Juli, 2007 33
PITZ : The shutdown• Controls• Control and data aquisition of elements of
reconstructed beam line and CTS• Control for new laser• Control of rf1• …..
-J.Bähr, PITZ, Technisches Seminar, 3.Juli, 2007 34
PITZ : The shutdown• Technical infrastructure• Second crane in tunnel• Reconstruction laser hutch• New climatisation and cooling for laser and
laser hutch• Extension of cooling in tunnel new elements
and CTS• Upgrade of cooling systems• ……• Partially done by external firms
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-J.Bähr, PITZ, Technisches Seminar, 3.Juli, 2007 35
PITZ : The shutdown• Laser hutch and laser• Extension of Laser: longitudinal profile: flat top with
rise and fall time of 1-2ps(10**-12)• Dismount laser• Extension of laser hutch• Climatisation, cooling , network, electric power• Cleaning• Mount new laser table• Mount new laser• Commissioning of laser: Beginning of November
-J.Bähr, PITZ, Technisches Seminar, 3.Juli, 2007 36
PITZ : The shutdown• To do: Preparation and during shutdown• Sequence of work• Coordination between technical groups• Delivery of components
• End of shutdown• Start running with new laser in test mode:
Beginning of November
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-J.Bähr, PITZ, Technisches Seminar, 3.Juli, 2007 37
PITZ : The shutdown• Flow chart
-J.Bähr, PITZ, Technisches Seminar, 3.Juli, 2007 38
PITZ : Outlook• Outlook
• PITZ1.7 PITZ 2 : 2008• HEDA2 :July 2008• Tomography module (March 2008)• Magnets• Rf deflector as option• CDS Booster (Jan. 2008) • Beam dump : 2m³ concreteJuly 2008
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-J.Bähr, PITZ, Technisches Seminar, 3.Juli, 2007 39
Comparison: PITZ1.6 ↔ PITZ2.0PITZ1.6:
PITZ2.0:
TESLA
CDS
• dipole is ready and tested,• technical design of dispersive arm ready,• parts in fabrication• installation starting August 20
• preliminary dispersive arm and beam dumpshave to be replaced by final components
• physics design is ongoing• sweeper under fabrication
tomography module + RF deflector arerealized depending on EU contracts,basic design available for both devices
tomography module + RF deflector arerealized depending on EU contracts,basic design available for both devices
-J.Bähr, PITZ, Technisches Seminar, 3.Juli, 2007 40
Acknowledgement• Thanks to F.Stephan, S. Rimjaem and S.
Khodyachykh for providing transparenciesand photos
• Thanks to S.Niedworok and Chr. Iezzi for theposter
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-J.Bähr, PITZ, Technisches Seminar, 3.Juli, 2007 41
PITZ shutdown 2007
• The end
-J.Bähr, PITZ, Technisches Seminar, 3.Juli, 2007 42
0,8
1,2
1,6
2,0
2,4
2,8
3,2
320 322 324 326 328 330Imain, A
norm
. em
ittan
ce /
mm
mra
d ExEySQRT(Ex*Ey)measured @ PITZ:
p = 5.2 MeV/c
Q = 1 nCΦ = Φm
Ibuck = Imain * 0.075(100% rms projected emittance)
Results from PITZ1:
Particularities, Results from PITZ1• PITZ source must drive super conducting linac long pulse trains,
i.e. high average power, good stability
• XFEL goes to very short wavelength very good emittance required
0.2
0.3
0.4
0.5
0.6
0.7
800 1000 1200 1400 1600 1800 2000 2200
t / μsec
a.u. Forward powerReflected power
e.g. 800 µs
~ log(power)long RF pulse:
amplified output train
pulse train from the oscillator
10 Hz, 800µs, 1 MHz
long laser pulse train:
VUV-FEL, 6nm
XFEL
C
WR
measured @ VUV-FEL:
p = 127 MeV/c
Q = 1 nC
• regularly obtain 2.1 mm mrad(100% rms projected emittance)
• minimum 1.1 mm mrad(90% rms projected emittance)
PITZ gun installed at VUV-FEL in 2004
22
first preliminary emittance results(not optimized yet !)
in operation: gun + booster 13.7 MeV/ccurrent booster: TESLA prototype
3,54
4,55
5,5
66,5
77,5
2 3 4 5 6 7 8
gun peak power, MW
Pmea
n, M
eV/c
38,4 44,3 49,6 54,3 58,7 62,7Ecath, MV/m
max. mean momentum ↔ gun power
goal: 60 MV/m
measured at PITZ2 (momentum of dark
current edge)
p = 12.8 MeV/c, Q = 1 nC,Φgun = Φmax_p, Φbooster =Φmin_dp
obtained at PITZ1
0
1
2
3
4
5
6
7
8
262 264 266 268 270 272 274 276 278 280 282Imain, A
Em
ittan
ce, [
mm
-mra
d]
Xemittance, measured
Yemittance, measured
Simulation (ASTRA)
First Results from PITZ2
Status: • new gun cavity (#3) installedand under conditioning now
• upgrade of beamline ongoing
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