FEL2014 - List of Keywords (detector)

Paper	Title	Other Keywords	Page
MOP010	The Photon Beam Loss Monitors as a Part of Equipment Protection System at European XFEL	photon, vacuum, radiation, beam-transport	37
	N. Gerasimova, H. Sinn XFEL. EU, Hamburg, Germany S. Dziarzhytski, R. Treusch DESY, Hamburg, Germany
	For the X-ray beam transport systems, the problem of potential damage to the equipment by mis-steered photon beam emerged with advent of powerful X-ray FELs. In particular high repetition rate machines as European XFEL, where not only focused beam can produce ablation, but even unfocused beam can melt the beamline components while machine operates in multibunch mode, demand for implementation of equipment protection. Here we report on development of photon beam loss monitors at European XFEL facility. The photon beam loss monitors will react on the mis-steered photon beam and interface the machine protection system. The prototype comprises the vacuum chamber with fluorescence crystals positioned outside the photon beampath. The fast sub-hundred ns fluorescence induced by mis-steered beam can be detected by photomultiplier tube allowing for intra-train reaction of machine protection system. First tests have been carried out at FLASH and shown the feasibility of detection based on PMT-detected fluorescence. In addition to efficient YAG:Ce crystal, the robust low-Z material as CVD microcrystalline diamonds has shown a potential to be used as fluorescence crystals.

MOP015	A Power Switching Ionization Profile Monitor (3D-IPM)	laser, electron, ion, vacuum	47
	H.F. Breede, H.-J. Grabosch, M. Sachwitz, L.V. Vu DESY Zeuthen, Zeuthen, Germany
	FLASH at DESY in Hamburg is a linear accelerator to produce soft x-ray laser light ranging from 4.1 to 45 nm. To ensure the operation stability of FLASH, monitoring of the beam is mandatory. Two Ionization Profile Monitors (IPM) detect the lateral x and y position and profile changes of the beam. The functional principle of the IPM is based on the detection of particles, generated by interaction of the beam with the residual gas in the beam line. The newly designed IPM enables the combined evaluation of the horizontal and vertical position as well as the profile. A compact monitor, consisting of two micro-channel plates (MCP) is assembled on a conducting cage along with toggled electric fields in a rectangular vacuum chamber. The particles created by the photon beam, drift in the homogenous electrical field towards the respective MCP, which produces an image of the beam profile on an attached phosphor screen. A camera for each MCP is used for assessment. This indirect detection scheme operates over a wide dynamic range and allows the live detection of the clear position and the shape of the beam. The final design is presented.
	Poster MOP015 [1.314 MB]

MOP017	Measurement of the Output Power in Millimeter Wave Free Electron Laser using the Electro Optic Sampling Method	laser, FEL, radiation, electron	50
	A. Klein Israeli Free Electron Laser, Ariel, Israel A. Abramovich Ariel University Center of Samaria, Faculty of Engineering, Ariel, Israel D. Borodin, A. Friedman Ariel University, Ariel, Israel H. S. Marks University of Tel-Aviv, Faculty of Engineering, Tel-Aviv, Israel
	Funding: this work funded in part by Israel Minstry of Defence In this experimental work an electro optic (EO) sampling method was demonstrated as a method to measure the output power of an Electrostatic Accelerator Free Electron Laser (EA-FEL). This 1.4 MeV EA-FEL was designed to operate at the millimeter wavelengths and it utilizes a corrugated waveguide and two Talbot effect quasi-optical reflectors with internal losses of ~30%. Millimeter wave radiation pulses of 10 μs at a frequency of about 100 GHz with peak power values of 1-2 kW were measured using conventional methods with an RF diode. Here we show the employment of an electro-optic sampling method using a ZnTe nonlinear crystal. A special quasi optical design directs the EA-FEL power towards the ZnTe nonlinear crystal, placed in the middle of a cross polarized configuration, coaxially with a polarized HeNe laser beam. The differences in the ZnTe optical axis due to the EA-FEL power affects the power levels of the HeNe laser transmission. This was measured using a polarizer and a balanced amplifier detector. We succeeded in obtaining a signal which corresponds to the theoretical calculation.

MOP049	Oxygen Scintillation in the LCLS	controls, laser, instrumentation, electron	137
	J.L. Turner, R.C. Field SLAC, Menlo Park, California, USA
	Funding: This work was supported by U.S. Department of Energy, Office of Basic Energy Sciences, under Contract DE-AC02-76SF00515 Oxygen is tested as a replacement for Nitrogen in the Gas Detector system in the Linac Coherent Light Source (LCLS) x-ray Free Electron Laser (FEL) at the SLAC National Accelerator Center. The attenuation and energy monitors for LCLS use Nitrogen, but for experiments at the Nitrogen K 1S energy of about 410eV this functionality is gone due to energy fluctuations above and below the K-edge. Oxygen was tested as a scintillating gas at 400eV and 8.3keV.

TUP097	Fast, Multi-band Photon Detectors based on Quantum Well Devices for Beam-monitoring in New Generation Light Sources	laser, photon, monitoring, electron	600
	T. Ganbold University of Trieste, School of Nanotechnology, Trieste, Italy M. Antonelli, G. Cautero, R. Cucini, D.M. Eichert, W.H. Jark, R.H. Menk Elettra-Sincrotrone Trieste S.C.p.A., Basovizza, Italy G. Biasiol IOM-CNR, Trieste, Italy
	In order to monitor the photon-beam position for both diagnostics and calibration purposes, we have investigated the possibility to use InGaAs/InAlAs Quantum Well (QW) devices as position-sensitive photon detectors for Free-Electron Laser (FEL) or Synchrotron Radiation (SR). Owing to their direct, low-energy band gap and high electron mobility, such QW devices may be used also at Room Temperature (RT) as fast multi-band sensors for photons ranging from visible light to hard X-rays. Moreover, internal charge-amplification mechanism can be applied for very low signal levels, while the high carrier mobility allows the design of very fast photon detectors with sub-nanosecond response times. Segmented QW sensors have been preliminary tested with 100-fs-wide UV laser pulses and X-ray SR. The reported results indicate that these devices respond with 100-ps rise-times to ultra-fast UV laser pulses. Besides, X-ray tests have shown that these detectors are sensitive to beam position and exhibit a good efficiency in the collection of photo-generated carriers.

THB03	Femtosecond-Stability Delivery of Synchronized RF-Signals to the Klystron Gallery over 1-km Optical Fibers	laser, timing, klystron, experiment	663
	J. Kim, K. Jung, J. Lim, J. Shin, H. Yang KAIST, Daejeon, Republic of Korea H.-S. Kang, C.-K. Min PAL, Pohang, Kyungbuk, Republic of Korea
	Funding: This work was supported by the PAL-XFEL Project and the National Research Foundation (Grant number 2012R1A2A2A01005544) of South Korea. We present our recent progress in optical frequency comb-based remote optical and RF distribution system at PAL-XFEL. A 238 MHz mode-locked Er-laser is used as an optical master oscillator (OMO), which is stabilized to a 2.856 GHz RF master oscillator (RMO) using a fiber- loop optical-microwave phase detector (FLOM-PD). We partly installed a pair of 1.15 km long fiber links through a cable duct to connect and OMO room to a klystron gallery in the PAL-XFEL Injector Test Facility (ITF). The fiber links are stabilized using balanced optical cross- correlators (BOC). A voltage controlled RF oscillator (VCO) is locked to the delivered optical pulse train using the second FLOM-PD. Residual timing jitter and drift between the two independently distributed optical pulse train and RF signal is measured at the klystron gallery. The results are 6.6 fs rms and 31 fs rms over 7 hours and 62 hours, respectively. This is the first comb-based optical/RF distribution and phase comparison in the klystron gallery environment.
	Slides THB03 [7.478 MB]

THP083	Coherent Radiation Diagnostics for Longitudinal Bunch Characterization at European XFEL	radiation, electron, feedback, diagnostics	925
	P. Peier, H. Dinter, C. Gerth DESY, Hamburg, Germany
	European XFEL comprises a 17.5 GeV linear accelerator for the generation of hard X-rays. Electron bunches from 20 pC to 1 nC will be produced with a length of a few ps in the RF gun and compressed by three orders of magnitude in three bunch compressor (BC) stages. European XFEL is designed to operate at 10 Hz delivering bunch trains with up to 2700 bunches separated by 222 ns. The high intra-bunch train repetition rate offers the unique possibility of stabilizing the machine with an intra-bunch train feedback, which puts in turn very high demand on fast longitudinal diagnostics. Two different systems will be installed in several positions of the machine. Five bunch compression monitors (BCM) will monitor the compression factor of each BC stage and used for intra-bunch train feedbacks. A THz spectrometer will be used to measure parasitically the longitudinal bunch profile after the energy collimator at 17.5 GeV beam energy. We will present concepts for fast longitudinal diagnostic for European XFEL based on coherent radiation, newest developments for high repetition rate measurements and simulations for the feedback capability of the system.

THP093	Coherent Electron Cooling Proof of Principle Phase 1 Instrumentation Status	electron, instrumentation, status, electronics	956
	D.M. Gassner, J.C. Brutus, R.L. Hulsart, V. Litvinenko, R.J. Michnoff, T.A. Miller, M.G. Minty, I. Pinayev, M. Wilinski BNL, Upton, Long Island, New York, USA
	Funding: Work supported by Brookhaven Science Associates, LLC under Contract No. DE-AC02-98CH10886 with the U.S. Department of Energy The purpose of the Coherent electron Cooling Proof-of- Principle (CeC PoP) [1] experiment being designed at RHIC is to demonstrate longitudinal (energy spread) cooling before the expected CD-2 for eRHIC. The scope of the experiment is to longitudinally cool a single bunch of 40 GeV/u gold ions in RHIC. The cooling facility will be installed inside the RHIC tunnel in 3 phases. The status of the instrumentation systems planned for phase 1 commissioning efforts will be described. This paper will also describe updates to the instrumentation systems proposed to meet the diagnostics challenges during the final phase of cooling commissioning [2]. These include measurements of beam intensity, emittance, energy spread, bunch length, position, and transverse alignment of electron and ion beams.

Paper

Title

Other Keywords

Page

MOP010

The Photon Beam Loss Monitors as a Part of Equipment Protection System at European XFEL

photon, vacuum, radiation, beam-transport

37

N. Gerasimova, H. Sinn
XFEL. EU, Hamburg, Germany
S. Dziarzhytski, R. Treusch
DESY, Hamburg, Germany

For the X-ray beam transport systems, the problem of potential damage to the equipment by mis-steered photon beam emerged with advent of powerful X-ray FELs. In particular high repetition rate machines as European XFEL, where not only focused beam can produce ablation, but even unfocused beam can melt the beamline components while machine operates in multibunch mode, demand for implementation of equipment protection. Here we report on development of photon beam loss monitors at European XFEL facility. The photon beam loss monitors will react on the mis-steered photon beam and interface the machine protection system. The prototype comprises the vacuum chamber with fluorescence crystals positioned outside the photon beampath. The fast sub-hundred ns fluorescence induced by mis-steered beam can be detected by photomultiplier tube allowing for intra-train reaction of machine protection system. First tests have been carried out at FLASH and shown the feasibility of detection based on PMT-detected fluorescence. In addition to efficient YAG:Ce crystal, the robust low-Z material as CVD microcrystalline diamonds has shown a potential to be used as fluorescence crystals.

MOP015

A Power Switching Ionization Profile Monitor (3D-IPM)

laser, electron, ion, vacuum

47

H.F. Breede, H.-J. Grabosch, M. Sachwitz, L.V. Vu
DESY Zeuthen, Zeuthen, Germany

FLASH at DESY in Hamburg is a linear accelerator to produce soft x-ray laser light ranging from 4.1 to 45 nm. To ensure the operation stability of FLASH, monitoring of the beam is mandatory. Two Ionization Profile Monitors (IPM) detect the lateral x and y position and profile changes of the beam. The functional principle of the IPM is based on the detection of particles, generated by interaction of the beam with the residual gas in the beam line. The newly designed IPM enables the combined evaluation of the horizontal and vertical position as well as the profile. A compact monitor, consisting of two micro-channel plates (MCP) is assembled on a conducting cage along with toggled electric fields in a rectangular vacuum chamber. The particles created by the photon beam, drift in the homogenous electrical field towards the respective MCP, which produces an image of the beam profile on an attached phosphor screen. A camera for each MCP is used for assessment. This indirect detection scheme operates over a wide dynamic range and allows the live detection of the clear position and the shape of the beam. The final design is presented.

Poster MOP015 [1.314 MB]

MOP017

Measurement of the Output Power in Millimeter Wave Free Electron Laser using the Electro Optic Sampling Method

laser, FEL, radiation, electron

50

A. Klein
Israeli Free Electron Laser, Ariel, Israel
A. Abramovich
Ariel University Center of Samaria, Faculty of Engineering, Ariel, Israel
D. Borodin, A. Friedman
Ariel University, Ariel, Israel
H. S. Marks
University of Tel-Aviv, Faculty of Engineering, Tel-Aviv, Israel

Funding: this work funded in part by Israel Minstry of Defence
In this experimental work an electro optic (EO) sampling method was demonstrated as a method to measure the output power of an Electrostatic Accelerator Free Electron Laser (EA-FEL). This 1.4 MeV EA-FEL was designed to operate at the millimeter wavelengths and it utilizes a corrugated waveguide and two Talbot effect quasi-optical reflectors with internal losses of ~30%. Millimeter wave radiation pulses of 10 μs at a frequency of about 100 GHz with peak power values of 1-2 kW were measured using conventional methods with an RF diode. Here we show the employment of an electro-optic sampling method using a ZnTe nonlinear crystal. A special quasi optical design directs the EA-FEL power towards the ZnTe nonlinear crystal, placed in the middle of a cross polarized configuration, coaxially with a polarized HeNe laser beam. The differences in the ZnTe optical axis due to the EA-FEL power affects the power levels of the HeNe laser transmission. This was measured using a polarizer and a balanced amplifier detector. We succeeded in obtaining a signal which corresponds to the theoretical calculation.

MOP049

Oxygen Scintillation in the LCLS

controls, laser, instrumentation, electron

137

J.L. Turner, R.C. Field
SLAC, Menlo Park, California, USA

Funding: This work was supported by U.S. Department of Energy, Office of Basic Energy Sciences, under Contract DE-AC02-76SF00515
Oxygen is tested as a replacement for Nitrogen in the Gas Detector system in the Linac Coherent Light Source (LCLS) x-ray Free Electron Laser (FEL) at the SLAC National Accelerator Center. The attenuation and energy monitors for LCLS use Nitrogen, but for experiments at the Nitrogen K 1S energy of about 410eV this functionality is gone due to energy fluctuations above and below the K-edge. Oxygen was tested as a scintillating gas at 400eV and 8.3keV.

TUP097

Fast, Multi-band Photon Detectors based on Quantum Well Devices for Beam-monitoring in New Generation Light Sources

laser, photon, monitoring, electron

600

T. Ganbold
University of Trieste, School of Nanotechnology, Trieste, Italy
M. Antonelli, G. Cautero, R. Cucini, D.M. Eichert, W.H. Jark, R.H. Menk
Elettra-Sincrotrone Trieste S.C.p.A., Basovizza, Italy
G. Biasiol
IOM-CNR, Trieste, Italy

In order to monitor the photon-beam position for both diagnostics and calibration purposes, we have investigated the possibility to use InGaAs/InAlAs Quantum Well (QW) devices as position-sensitive photon detectors for Free-Electron Laser (FEL) or Synchrotron Radiation (SR). Owing to their direct, low-energy band gap and high electron mobility, such QW devices may be used also at Room Temperature (RT) as fast multi-band sensors for photons ranging from visible light to hard X-rays. Moreover, internal charge-amplification mechanism can be applied for very low signal levels, while the high carrier mobility allows the design of very fast photon detectors with sub-nanosecond response times. Segmented QW sensors have been preliminary tested with 100-fs-wide UV laser pulses and X-ray SR. The reported results indicate that these devices respond with 100-ps rise-times to ultra-fast UV laser pulses. Besides, X-ray tests have shown that these detectors are sensitive to beam position and exhibit a good efficiency in the collection of photo-generated carriers.

THB03

Femtosecond-Stability Delivery of Synchronized RF-Signals to the Klystron Gallery over 1-km Optical Fibers

laser, timing, klystron, experiment

663

J. Kim, K. Jung, J. Lim, J. Shin, H. Yang
KAIST, Daejeon, Republic of Korea
H.-S. Kang, C.-K. Min
PAL, Pohang, Kyungbuk, Republic of Korea

Funding: This work was supported by the PAL-XFEL Project and the National Research Foundation (Grant number 2012R1A2A2A01005544) of South Korea.
We present our recent progress in optical frequency comb-based remote optical and RF distribution system at PAL-XFEL. A 238 MHz mode-locked Er-laser is used as an optical master oscillator (OMO), which is stabilized to a 2.856 GHz RF master oscillator (RMO) using a fiber- loop optical-microwave phase detector (FLOM-PD). We partly installed a pair of 1.15 km long fiber links through a cable duct to connect and OMO room to a klystron gallery in the PAL-XFEL Injector Test Facility (ITF). The fiber links are stabilized using balanced optical cross- correlators (BOC). A voltage controlled RF oscillator (VCO) is locked to the delivered optical pulse train using the second FLOM-PD. Residual timing jitter and drift between the two independently distributed optical pulse train and RF signal is measured at the klystron gallery. The results are 6.6 fs rms and 31 fs rms over 7 hours and 62 hours, respectively. This is the first comb-based optical/RF distribution and phase comparison in the klystron gallery environment.

Slides THB03 [7.478 MB]

THP083

Coherent Radiation Diagnostics for Longitudinal Bunch Characterization at European XFEL

radiation, electron, feedback, diagnostics

925

P. Peier, H. Dinter, C. Gerth
DESY, Hamburg, Germany

European XFEL comprises a 17.5 GeV linear accelerator for the generation of hard X-rays. Electron bunches from 20 pC to 1 nC will be produced with a length of a few ps in the RF gun and compressed by three orders of magnitude in three bunch compressor (BC) stages. European XFEL is designed to operate at 10 Hz delivering bunch trains with up to 2700 bunches separated by 222 ns. The high intra-bunch train repetition rate offers the unique possibility of stabilizing the machine with an intra-bunch train feedback, which puts in turn very high demand on fast longitudinal diagnostics. Two different systems will be installed in several positions of the machine. Five bunch compression monitors (BCM) will monitor the compression factor of each BC stage and used for intra-bunch train feedbacks. A THz spectrometer will be used to measure parasitically the longitudinal bunch profile after the energy collimator at 17.5 GeV beam energy. We will present concepts for fast longitudinal diagnostic for European XFEL based on coherent radiation, newest developments for high repetition rate measurements and simulations for the feedback capability of the system.

THP093

Coherent Electron Cooling Proof of Principle Phase 1 Instrumentation Status

electron, instrumentation, status, electronics

956

D.M. Gassner, J.C. Brutus, R.L. Hulsart, V. Litvinenko, R.J. Michnoff, T.A. Miller, M.G. Minty, I. Pinayev, M. Wilinski
BNL, Upton, Long Island, New York, USA

Funding: Work supported by Brookhaven Science Associates, LLC under Contract No. DE-AC02-98CH10886 with the U.S. Department of Energy
The purpose of the Coherent electron Cooling Proof-of- Principle (CeC PoP) [1] experiment being designed at RHIC is to demonstrate longitudinal (energy spread) cooling before the expected CD-2 for eRHIC. The scope of the experiment is to longitudinally cool a single bunch of 40 GeV/u gold ions in RHIC. The cooling facility will be installed inside the RHIC tunnel in 3 phases. The status of the instrumentation systems planned for phase 1 commissioning efforts will be described. This paper will also describe updates to the instrumentation systems proposed to meet the diagnostics challenges during the final phase of cooling commissioning [2]. These include measurements of beam intensity, emittance, energy spread, bunch length, position, and transverse alignment of electron and ion beams.