Rosemarie Hunziker, PhD Program Director, Tissue Engineering/Regenerative Medicine,
Overview of SwissFEL Diagnostics · 2015. 7. 14. · Erny, Franziska Frei, Romain Ganter, Stephan...
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Overview of SwissFEL Diagnostics Bunch Compression Monitors Beam Position Monitor Bunch Arrival Monitor Transverse Profile Imager Current Measurement Dose Rate Monitor Wire Scanners SR Imager Terahertz Streak Camera Loss Monitors -1.5 -1 -0.5 0 0.5 1 1.5 2 2.5 -0.2 0 0.2 0.4 0.6 0.8 1 1.2 Vertical Axis (mm) ) t i n U . b r A ( l a n g i S r o t c e t e D WSC vs. OTR meas OTR WSC SwissFEL will provide users with brilliant X-ray pulses in 2017. A comprehensive suite of diagnostics is needed for the initial commissioning, for changes to the oper- ating point, and for feedbacks. The devel- opment of instrumen- tation for SwissFEL is well underway, and solutions have been identified for most di- agnostics systems. I will present here an overview of the instru- mentation for Swiss- FEL, and give details on some recent devel- opments. Bunch length after BC1: 250 – 500 fs rms. BCM measuring two different spectral bands (0.26 – 2 THz and 0.6 – 2 THz) by using “thick grid” high pass THz filters and fast Schottky diodes Experimental results on varying the compression phase (FINSB03-P) and the phase of the fourth har- monic (FINXB-P) for a bunch length of roughly 260 fs and a bunch charge of 20.5 pC (energy: 200 MeV). Top two raws: BCM signals integrated in the two spectral ranges, bottom raw: bunch length measured by the transverse de- flecting cavity. Bunch length after BC2: 3 – 75 fs. Design of a prism based spec- trometer, using an MCT array, is currently under investigation. 0 5 10 15 20 25 30 35 0 50 100 150 200 250 300 Charge / pC Core slice emittance / nm eTOF1 eTOF2 Gas Jet HHG X-rays Thz Radiation Parabolic Mirror with Hole -5 0 5 10 15 20 25 0 0.5 1 1.5 2 2.5 3 3.5 4 x 10 -3 OFF-RF-crest phase (Deg) Relative Energy Spread ( Δ Δ Δ Δ E/E, RMS) HE Spectrometer BC-YAG Monitor BC-SR Monitor NUM.SIM. 230 MeV, 12 pC Rasmus Ischebeck, Rafael Abela, Vladimir Arsov, Raphael Baldinger, Hans-Heinrich Braun, Marco Calvi, Robin Ditter, Christian Erny, Franziska Frei, Romain Ganter, Stephan Hunziker, Yevgeniy Ivanisenko, Pavle Juranic, Boris Keil, Waldemar Koprek, Reinhold Kramert, Daniel Llorente Sancho, Florian Loehl, Fabio Marcellini, Goran Marinkovic, Balazs Monoszlai, Gian Luca Orlandi, Cigdem Ozkan, Luc Patthey, Marco Pedrozzi, Patrick Pollet, Milan Radovic, Markus Roggli, Martin Rohrer, Volker Schlott, Markus Stadler, Andrey Stepanov, Jerome Stettler, Daniel Marco Treyer (PSI, Villigen PSI), Peter Peier (DESY, Hamburg), Fernando Ardana-Lamas, Ishkhan Gorgisyan, Christoph P. Hauri, Leonid Rivkin (EPFL, Lausanne; PSI, Villigen PSI) SwissFEL BPM16 position resolution measure- ment: difference between SwssFEL and XFEL.EU (extrapolated) BPM position reading RMS noise < 0.8 µm 135 pC Improvements 2014: button pick-ups equipped with 40 GHz vacuum feedthroughs, EOMs with 33 GHz bandwidth (40 Gs/s) and small half-wave voltage (4.6 V), DC-offset DAC, improved photoreceiver. Intrinsic resolution: 10 fs - 13 fs @ 90…200 pC, 13 fs - 40 fs @ 20…90 pC. Optical resolution (ISO 12223): 8 µm Field of view: 6 mm (h) x 16 mm (v) Dynamic range > 20ʼ000:1 Slice emittance measurement as a function of bunch charge Comparison of energy spread measurements using the SR imager with measurements using scintillators in the bunch compressor as well as just before the beam dump, and with a numerical model On-line measurement of dose rate with a RadFET, during the undulator ex- periment A longitudinal loss monitor, consisting of a fiber optic cable installed along the beamline, allows determining the location of beam losses The newly developed Turbo ICT makes use of several ferrites whose signals are combined to reduce the noise floor. A signal-to-noise ratio of more than 60 is obtained for the SwissFEL charge range of 10 to 200 pC. The measurement shown above is limited by the charge variations in the beam. Design of the transverse profile imager takes Snellʼs law of refraction and the Scheimp- flug imaging condition into account to achieve good resolution over a large field of view. Coherent OTR is directed away from the imaging system. Wire fork inserted at 45º allows measure- ment of horizontal and vertical profile with one UHV feedtrhough The normalized signal from the THz scan for 10 keV photon beam. The spectrum of the photoelectrons changes during the scan in accordance to the shape of the vector potential. DESY Time [ps] Retarded energy [eV] eTOF1 2 2.5 3 3.5 4 4.5 350 400 450 500 550 Time [ps] Retarded energy [eV] eTOF2 2 2.5 3 3.5 4 4.5 400 450 500 550 600 0 0.2 0.4 0.6 0.8 0 0.2 0.4 0.6 0.8 1 This monitor will be used for a beam-based calibration of the cavity BPMs.
Transcript of Overview of SwissFEL Diagnostics · 2015. 7. 14. · Erny, Franziska Frei, Romain Ganter, Stephan...
Overview of SwissFEL Diagnostics
Bunch Compression Monitors
Beam Position Monitor
Bunch Arrival MonitorTransverse Profile Imager
Current MeasurementDose Rate Monitor
Wire Scanners
SR Imager
Terahertz Streak Camera
Loss Monitors
-1.5 -1 -0.5 0 0.5 1 1.5 2 2.5-0.2
0
0.2
0.4
0.6
0.8
1
1.2
Vertical Axis (mm)
)tinU.br
A(langiSrotcete
D
WSC vs. OTR meas
OTRWSC
SwissFEL will provide users with brilliant X-ray pulses in 2017. A comprehensive suite of diagnostics is needed for the initial commissioning, for changes to the oper-ating point, and for feedbacks. The devel-opment of instrumen-tation for SwissFEL is well underway, and solutions have been identified for most di-agnostics systems. I will present here an overview of the instru-mentation for Swiss-FEL, and give details on some recent devel-opments.
Bunch length after BC1: 250 – 500 fs rms.BCM measuring two different spectral bands (0.26 – 2 THz and 0.6 – 2 THz) by using “thick grid” high pass THz filters and fast Schottky diodes
Experimental results on varying the compression phase (FINSB03-P) and the phase of the fourth har-monic (FINXB-P) for a bunch length of roughly 260 fs and a bunch charge of 20.5 pC (energy: 200 MeV). Top two raws: BCM signals integrated in the two spectral ranges, bottom raw: bunch length measured by the transverse de-flecting cavity.
Bunch length after BC2: 3 – 75 fs.Design of a prism based spec-trometer, using an MCT array, is currently under investigation.
0 5 10 15 20 25 30 350
50
100
150
200
250
300
Charge / pC
Cor
e sl
ice
emitt
ance
/ nm
eTOF1 eTOF2
Gas Jet
HHG X-rays
Thz Radiation
Parabolic Mirrorwith Hole
-5 0 5 10 15 20 250
0.5
1
1.5
2
2.5
3
3.5
4x 10-3
OFF-RF-crest phase (Deg)
Rel
ativ
e En
ergy
Spr
ead
( ΔΔ ΔΔE/
E, R
MS) HE Spectrometer
BC-YAG MonitorBC-SR MonitorNUM.SIM.
230 MeV, 12 pC
Rasmus Ischebeck, Rafael Abela, Vladimir Arsov, Raphael Baldinger, Hans-Heinrich Braun, Marco Calvi, Robin Ditter, Christian Erny, Franziska Frei, Romain Ganter, Stephan Hunziker, Yevgeniy Ivanisenko, Pavle Juranic, Boris Keil, Waldemar Koprek, Reinhold Kramert, Daniel Llorente Sancho, Florian Loehl, Fabio Marcellini, Goran Marinkovic, Balazs Monoszlai, Gian Luca Orlandi, Cigdem Ozkan, Luc Patthey, Marco Pedrozzi, Patrick Pollet, Milan Radovic, Markus Roggli, Martin Rohrer, Volker Schlott, Markus Stadler, Andrey Stepanov, Jerome Stettler, Daniel Marco Treyer (PSI, Villigen PSI), Peter Peier (DESY, Hamburg), Fernando Ardana-Lamas, Ishkhan Gorgisyan, Christoph P. Hauri, Leonid Rivkin (EPFL, Lausanne; PSI, Villigen PSI)
SwissFEL BPM16 position resolution measure-ment: difference between SwssFEL and XFEL.EU (extrapolated) BPM position reading
RMS noise < 0.8 µm
135 pC
Improvements 2014: button pick-ups equipped with 40 GHz vacuum feedthroughs, EOMs with 33 GHz bandwidth (40 Gs/s) and smallhalf-wave voltage (4.6 V), DC-offset DAC, improved photoreceiver.Intrinsic resolution: 10 fs - 13 fs @ 90…200 pC, 13 fs - 40 fs @ 20…90 pC.
Optical resolution (ISO 12223): 8 µmField of view: 6 mm (h) x 16 mm (v) Dynamic range > 20ʼ000:1
Slice emittance measurement as a function of bunch charge
Comparison of energy spread measurements using the SR imager with measurements using scintillators in the bunch compressor as well as just before the beam dump, and with a numerical model
On-line measurement of dose rate with a RadFET, during the undulator ex-periment
A longitudinal loss monitor, consisting of a fiber optic cable installed along the beamline, allows determining the location of beam losses
The newly developed Turbo ICT makes use of several ferrites whose signals are combined to reduce the noise floor. A signal-to-noise ratio of more than 60 is obtained for the SwissFEL charge range of 10 to 200 pC. The measurement shown above is limited by the charge variations in the beam.
Design of the transverse profile imager takes Snellʼs law of refraction and the Scheimp-flug imaging condition into account to achieve good resolution over a large field of view.Coherent OTR is directed away from the imaging system.
Wire fork inserted at 45º allows measure-ment of horizontal and vertical profile with one UHV feedtrhough
The normalized signal from the THz scan for 10 keV photon beam. The spectrum of the photoelectrons changes during the scan in accordance to the shape of the vector potential.
DESY
Time [ps]
Retar
ded e
nerg
y [eV
]
eTOF1
2 2.5 3 3.5 4 4.5350
400
450
500
550
Time [ps]
Retar
ded e
nerg
y [eV
]
eTOF2
2 2.5 3 3.5 4 4.5400
450
500
550
600
0
0.2
0.4
0.6
0.8
0
0.2
0.4
0.6
0.8
1
This monitor will be used for a beam-based calibration of the cavity BPMs.
