IBIC2013 - List of Keywords (OTR)

Paper	Title	Other Keywords	Page
MOCL1	Beam Instrumentation at the Accelerator Test Facility 2	laser, electron, feedback, emittance	26
	S.T. Boogert JAI, Egham, Surrey, United Kingdom S.T. Boogert Royal Holloway, University of London, Surrey, United Kingdom
	The Accelerator Test Facility 2 (ATF2) is a scaled demonstrator system for final focus beam lines of linear high energy colliders. Four OTR (Optical Transition Radiation) monitors have been installed at the ATF2. Major characteristics is the fast measurement of projected (2D) and intrinsic (4D) emittances and the coupling corrections with skew quadrupole magnets at the upstream. The high resolution cavity beam position monitor (BPM) system is a part of the ATF2 diagnostics. Two types of cavity BPMs are used, C-band operating at 6.426 GHz, and S-band at 2.888 GHz with an increased beam aperture. The resolution of the C-band system with attenuators was determined to be approximately 250 nm and 1 μm for the S-band system. Without attenuation the best recorded C-band cavity resolution was 27 nm. A laser-wire transverse electron beam size measurement system has been constructed and operated at the ATF2 beam line at KEK. A special set of electron beam optics was developed to generate an approximately 1μm vertical focus at the laser-wire location. Systematic measurements of a micron beam size have been successfully executed.
	Slides MOCL1 [6.059 MB]

MOPF04	Results of the High Resolution OTR Measurements at KEK and Comparison with Simulations	simulation, radiation, KEK, target	204
	B. Bolzon, C.P. Welsch Cockcroft Institute, Warrington, Cheshire, United Kingdom A.S. Aryshev KEK, Ibaraki, Japan B. Bolzon, T. Lefèvre, S. Mazzoni CERN, Geneva, Switzerland B. Bolzon, C.P. Welsch The University of Liverpool, Liverpool, United Kingdom P. Karataev, K.O. Kruchinin Royal Holloway, University of London, Surrey, United Kingdom P. Karataev JAI, Egham, Surrey, United Kingdom
	Optical Transition Radiation (OTR) is emitted when a charged particle crosses the interface between two media with different dielectric properties. It has become a standard tool for beam imaging and transverse beam size measurements. At the KEK Accelerator Test Facility 2 (ATF2), OTR is used at the beginning of the final focus system to measure a micrometre beam size using the decrease in visibility of the OTR Point Spread Function (PSF). In order to study and improve the resolution of the optical system, a novel simulation tool has been developed in order to characterize the PSF in detail. Based on the physical optic propagation mode of ZEMAX, the propagation of the OTR electric field can be simulated very precisely up to the image plane, taking into account aberrations and diffraction coming through the designed optical system. This contribution will show the results of measurements performed after a first improvement of the ATF2 OTR optical design to confirm the very high resolution of the imaging system and the performance of this simulation tool.
	Poster MOPF04 [1.590 MB]

MOPF07	Turn by Turn Profile Monitors for the CERN SPS and LHC	LHC, SPS, optics, proton	216
	S. Burger, A. Boccardi, E. Bravin, A. Goldblatt, A. Ravni, F. Roncarolo, R.S. Sautier CERN, Geneva, Switzerland
	In order to preserve the transverse beam emittance along the acceleration chain it is important that the optics of the transfer lines is perfectly matched to the optics of the rings. Special monitors capable of measuring the beam profiles with a turn by turn resolution are very helpful in this respect. A new type of matching monitor has been developed at CERN for the SPS and LHC machines. This monitor relies on imaging OTR light by mean of a fast line scan CMOS and an asymmetric optical system based on cylindrical lenses. This contribution describes the design of this monitor, presents the results obtained during the 2012-13 run and outlines the plans for further improving the design.

MOPF13	Transverse Beam Profiling for FAIR	ion, IPM, GSI, UNILAC	232
	M. Schwickert, C.A. Andre, F. Becker, P. Forck, T. Giacomini, E. Gütlich, T. Hoffmann, A. Lieberwirth, S. Löchner, A. Reiter, B. Voss, B. Walasek-Höhne, M. Witthaus GSI, Darmstadt, Germany
	The FAIR facility will provide intense primary beams of protons and heavy ions, or secondary beams of antiproton and rare isotopes. The operation includes fixed-target experiments or subsequent facilities of independent storage rings and experiment beam lines. The particle beams greatly differ in ion species, intensity, time structure, spot size and stopping power. Therefore, transverse beam profile measurements require a careful choice of detector type for each location in order to cope with the large dynamic range and operational demands. This contribution presents the actual status of FAIR detector developments for intercepting devices (SEM-Grids, Multi-Wire Proportional Chambers, Scintillating Screens) as well as non-intercepting Beam Induced Fluorescence Monitors and Ionization Profile Monitors. Recently, promising results were obtained with slow extracted heavy ion beams in measurements of optical transmission radiation emitted from thin metal foils. The boundaries for the application area are described and basic detector parameters are summarized.

MOPF16	Sub-Micrometre Resolution Laserwire Transverse Beam Size Measurement System	laser, electron, transverse, photon	243
	L.J. Nevay JAI, Egham, Surrey, United Kingdom A.S. Aryshev, N. Terunuma, J. Urakawa KEK, Ibaraki, Japan S.T. Boogert, P. Karataev, K.O. Kruchinin Royal Holloway, University of London, Surrey, United Kingdom L. Corner, R. Walczak Oxford University, Physics Department, Oxford, Oxon, United Kingdom
	The laserwire system at the Accelerator Test Facility 2 (ATF2) is a transverse beam profile measurement system capable of measuring a micrometre-size electron beam. We present recent results demonstrating a measured vertical size of 1.16 ± 0.06 μm and a horizontal size of 110.1 ± 3.8 μm. Due to the high aspect ratio of the electron beam, the natural divergence of the tightly focussed laser beam across the electron beam width requires the use of the full overlap integral to deconvolve the scans. For this to be done accurately, the propagation of the 150 mJ, 167 ps long laser pulses was precisely measured at a scaled virtual interaction point.

TUPC40	Bunch Length Measurements Using Correlation Theory in Incoherent Optical Transition Radiation	electron, radiation, longitudinal, laser	471
	B. Smit, F. Frei, R. Ischebeck, G.L. Orlandi, V. Schlott PSI, Villigen PSI, Switzerland
	Funding: Paul Scherrer Institut (PSI) As Free Electron Lasers create ultra-short bunch lengths, the longitudinal diagnostic for such femto-second bunches becomes more difficult. We suggest a bunch length method using the spectral analysis of incoherent Optical Transition Radiation (OTR) in the visible frequency domain. The frequency response of OTR is taken by inserting an aluminium coated silicon wafer into the electron beam. The OTR light is collected with mirror optics into an optical fibre, which is coupled to a spectrometer (334 THz to 1500 THz). The resolution of the spectrometer allows us to measure bunch length lower than 100 fs rms. Bunch length was varied from 100 femto-seconds down to a few femto-seconds. The spectral response of Optical Transition Radiation (OTR) showed an increase of the correlation between neighbouring frequencies as bunch length was reduced.

WEAL2	Extremely Low Emittance Beam Size Diagnostics with Sub-Micrometer Resolution Using Optical Transition Radiation	laser, vacuum, electron, transverse	615
	K.O. Kruchinin, S.T. Boogert, P. Karataev, L.J. Nevay Royal Holloway, University of London, Surrey, United Kingdom A.S. Aryshev, M.V. Shevelev, N. Terunuma, J. Urakawa KEK, Ibaraki, Japan B. Bolzon The University of Liverpool, Liverpool, United Kingdom B. Bolzon, T. Lefèvre, S. Mazzoni CERN, Geneva, Switzerland
	Transverse electron beam diagnostics is crucial for stable and reliable operation of the future electron-positron linear colliders such as CLIC or Higgs Factory. The-state-of-the-art in transverse beam diagnostics is based on the laser-wire technology. However, it requires a high power laser significantly increases the cost of the laser-wire system. Therefore, a simpler and relatively inexpensive method is required. A beam profile monitor based on Optical Transition Radiation (OTR) is very promising. The resolution of conventional OTR monitor is defined by a root-mean-square of the so-called Point Spread Function (PSF). In optical wavelength range the resolution is diffraction limited down to a few micrometers. However, in * we demonstrated that the OTR PSF has a structure which visibility can be used to monitor vertical beam size with sub-micrometer resolution. In this report we shall represent the recent experimental results of a micron-scale beam size measurement. We shall describe the entire method including calibration procedure, new analysis, and calculation of uncertainties. We shall discuss the hardware status and future plans. * P. Karataev et al., Physical Review Letters 107, 174801 (2011).
	Slides WEAL2 [5.120 MB]

WEPF03	Scintillating Screen Monitors for Transverse Electron Beam Profile Diagnostics at the European XFEL	electron, XFEL, transverse, DESY	807
	Ch. Wiebers, M. Holz, G. Kube, D. Nölle, G. Priebe, H.-Ch. Schröder DESY, Hamburg, Germany
	Transverse beam profile diagnostics in modern electron linear accelerators like FELs or injector LINACs are mainly based on optical transition radiation (OTR) as standard technique which is observed in backward direction when a charged particle beam crosses the boundary between two media with different dielectric properties. The experience from modern LINAC based 4th generation light sources shows that OTR diagnostics might fail because of coherence effects in the OTR emission process. As a consequence, for the European XFEL which is currently under construction in Hamburg, transverse beam profile measurements are based on scintillating screen monitors. The LYSO:Ce screens are oriented such that coherent OTR generated at the screen boundaries will be geometrically suppressed. An additional advantage is that the imaging optics operate in Scheimpflug condition thus adjusting the plane of sharp focus with respect to the CCD chip and significantly increasing the apparent depth of field. This report gives an overview of the measuring principle and the monitor setup together with results of laboratory test measurements and a first prototype test at FLASH (DESY, Hamburg).

WEPF18	Zemax Simulations of Diffraction and Transition Radiation	simulation, radiation, target, electron	852
	T. Aumeyr, P. Karataev JAI, Egham, Surrey, United Kingdom M.G. Billing Cornell University (CLASSE), Cornell Laboratory for Accelerator-Based Sciences and Education, Ithaca, New York, USA L.M. Bobb, B. Bolzon, T. Lefèvre, S. Mazzoni CERN, Geneva, Switzerland
	Diffraction Radiation (DR) and Transition Radiation (TR) are produced when a relativistic charged particle moves in the vicinity of a medium or through a medium respectively. The target atoms are polarised by the electric field of the charged particle, which then oscillate thus emitting radiation with a very broad spectrum. The spatial-spectral properties of DR/TR are sensitive to various electron beam parameters. Several projects aim to measure the transverse (vertical) beam size using DR or TR. This paper reports on how numerical simulations using Zemax can be used to study such a system.
	Poster WEPF18 [0.573 MB]

WEPF23	Beam Diagnostics R&D within oPAC	radiation, diagnostics, transverse, simulation	864
	C.P. Welsch Cockcroft Institute, Warrington, Cheshire, United Kingdom C.P. Welsch The University of Liverpool, Liverpool, United Kingdom
	Funding: oPAC is funded by the European Commission under Grant Agreement Number 289485. Optimization of particle accelerators by combining research into beam physics, beam instrumentation, accelerator control systems and numerical simulation studies is the goal of the oPAC project. Supported with 6 Million Euros by the European Union, the network is one of the largest-ever Initial Training Networks. During the project's four year duration 22 fellows will be trained and a very broad international training program, consisting of schools, topical workshops and conferences will be organized by a consortium of currently more than 30 partner institutions. In this contribution, we will give an overview of oPAC's broad beam diagnostics R&D program, comprising absolute beam intensity measurements for low energy beams, beam diagnostics for synchrotron light sources, cyrogenic beam loss monitors, beam halo monitoring and 3D dose measurements as part of intensity modulated radiotherapy treatment. We will also summarize past oPAC events and give an outlook on future events.

Paper

Title

Other Keywords

Page

MOCL1

Beam Instrumentation at the Accelerator Test Facility 2

laser, electron, feedback, emittance

26

S.T. Boogert
JAI, Egham, Surrey, United Kingdom
S.T. Boogert
Royal Holloway, University of London, Surrey, United Kingdom

The Accelerator Test Facility 2 (ATF2) is a scaled demonstrator system for final focus beam lines of linear high energy colliders. Four OTR (Optical Transition Radiation) monitors have been installed at the ATF2. Major characteristics is the fast measurement of projected (2D) and intrinsic (4D) emittances and the coupling corrections with skew quadrupole magnets at the upstream. The high resolution cavity beam position monitor (BPM) system is a part of the ATF2 diagnostics. Two types of cavity BPMs are used, C-band operating at 6.426 GHz, and S-band at 2.888 GHz with an increased beam aperture. The resolution of the C-band system with attenuators was determined to be approximately 250 nm and 1 μm for the S-band system. Without attenuation the best recorded C-band cavity resolution was 27 nm. A laser-wire transverse electron beam size measurement system has been constructed and operated at the ATF2 beam line at KEK. A special set of electron beam optics was developed to generate an approximately 1μm vertical focus at the laser-wire location. Systematic measurements of a micron beam size have been successfully executed.

Slides MOCL1 [6.059 MB]

MOPF04

Results of the High Resolution OTR Measurements at KEK and Comparison with Simulations

simulation, radiation, KEK, target

204

B. Bolzon, C.P. Welsch
Cockcroft Institute, Warrington, Cheshire, United Kingdom
A.S. Aryshev
KEK, Ibaraki, Japan
B. Bolzon, T. Lefèvre, S. Mazzoni
CERN, Geneva, Switzerland
B. Bolzon, C.P. Welsch
The University of Liverpool, Liverpool, United Kingdom
P. Karataev, K.O. Kruchinin
Royal Holloway, University of London, Surrey, United Kingdom
P. Karataev
JAI, Egham, Surrey, United Kingdom

Optical Transition Radiation (OTR) is emitted when a charged particle crosses the interface between two media with different dielectric properties. It has become a standard tool for beam imaging and transverse beam size measurements. At the KEK Accelerator Test Facility 2 (ATF2), OTR is used at the beginning of the final focus system to measure a micrometre beam size using the decrease in visibility of the OTR Point Spread Function (PSF). In order to study and improve the resolution of the optical system, a novel simulation tool has been developed in order to characterize the PSF in detail. Based on the physical optic propagation mode of ZEMAX, the propagation of the OTR electric field can be simulated very precisely up to the image plane, taking into account aberrations and diffraction coming through the designed optical system. This contribution will show the results of measurements performed after a first improvement of the ATF2 OTR optical design to confirm the very high resolution of the imaging system and the performance of this simulation tool.

Poster MOPF04 [1.590 MB]

MOPF07

Turn by Turn Profile Monitors for the CERN SPS and LHC

LHC, SPS, optics, proton

216

S. Burger, A. Boccardi, E. Bravin, A. Goldblatt, A. Ravni, F. Roncarolo, R.S. Sautier
CERN, Geneva, Switzerland

In order to preserve the transverse beam emittance along the acceleration chain it is important that the optics of the transfer lines is perfectly matched to the optics of the rings. Special monitors capable of measuring the beam profiles with a turn by turn resolution are very helpful in this respect. A new type of matching monitor has been developed at CERN for the SPS and LHC machines. This monitor relies on imaging OTR light by mean of a fast line scan CMOS and an asymmetric optical system based on cylindrical lenses. This contribution describes the design of this monitor, presents the results obtained during the 2012-13 run and outlines the plans for further improving the design.

MOPF13

Transverse Beam Profiling for FAIR

ion, IPM, GSI, UNILAC

232

M. Schwickert, C.A. Andre, F. Becker, P. Forck, T. Giacomini, E. Gütlich, T. Hoffmann, A. Lieberwirth, S. Löchner, A. Reiter, B. Voss, B. Walasek-Höhne, M. Witthaus
GSI, Darmstadt, Germany

The FAIR facility will provide intense primary beams of protons and heavy ions, or secondary beams of antiproton and rare isotopes. The operation includes fixed-target experiments or subsequent facilities of independent storage rings and experiment beam lines. The particle beams greatly differ in ion species, intensity, time structure, spot size and stopping power. Therefore, transverse beam profile measurements require a careful choice of detector type for each location in order to cope with the large dynamic range and operational demands. This contribution presents the actual status of FAIR detector developments for intercepting devices (SEM-Grids, Multi-Wire Proportional Chambers, Scintillating Screens) as well as non-intercepting Beam Induced Fluorescence Monitors and Ionization Profile Monitors. Recently, promising results were obtained with slow extracted heavy ion beams in measurements of optical transmission radiation emitted from thin metal foils. The boundaries for the application area are described and basic detector parameters are summarized.

MOPF16

Sub-Micrometre Resolution Laserwire Transverse Beam Size Measurement System

laser, electron, transverse, photon

243

L.J. Nevay
JAI, Egham, Surrey, United Kingdom
A.S. Aryshev, N. Terunuma, J. Urakawa
KEK, Ibaraki, Japan
S.T. Boogert, P. Karataev, K.O. Kruchinin
Royal Holloway, University of London, Surrey, United Kingdom
L. Corner, R. Walczak
Oxford University, Physics Department, Oxford, Oxon, United Kingdom

The laserwire system at the Accelerator Test Facility 2 (ATF2) is a transverse beam profile measurement system capable of measuring a micrometre-size electron beam. We present recent results demonstrating a measured vertical size of 1.16 ± 0.06 μm and a horizontal size of 110.1 ± 3.8 μm. Due to the high aspect ratio of the electron beam, the natural divergence of the tightly focussed laser beam across the electron beam width requires the use of the full overlap integral to deconvolve the scans. For this to be done accurately, the propagation of the 150 mJ, 167 ps long laser pulses was precisely measured at a scaled virtual interaction point.

TUPC40

Bunch Length Measurements Using Correlation Theory in Incoherent Optical Transition Radiation

electron, radiation, longitudinal, laser

471

B. Smit, F. Frei, R. Ischebeck, G.L. Orlandi, V. Schlott
PSI, Villigen PSI, Switzerland

Funding: Paul Scherrer Institut (PSI)
As Free Electron Lasers create ultra-short bunch lengths, the longitudinal diagnostic for such femto-second bunches becomes more difficult. We suggest a bunch length method using the spectral analysis of incoherent Optical Transition Radiation (OTR) in the visible frequency domain. The frequency response of OTR is taken by inserting an aluminium coated silicon wafer into the electron beam. The OTR light is collected with mirror optics into an optical fibre, which is coupled to a spectrometer (334 THz to 1500 THz). The resolution of the spectrometer allows us to measure bunch length lower than 100 fs rms. Bunch length was varied from 100 femto-seconds down to a few femto-seconds. The spectral response of Optical Transition Radiation (OTR) showed an increase of the correlation between neighbouring frequencies as bunch length was reduced.

WEAL2

Extremely Low Emittance Beam Size Diagnostics with Sub-Micrometer Resolution Using Optical Transition Radiation

laser, vacuum, electron, transverse

615

K.O. Kruchinin, S.T. Boogert, P. Karataev, L.J. Nevay
Royal Holloway, University of London, Surrey, United Kingdom
A.S. Aryshev, M.V. Shevelev, N. Terunuma, J. Urakawa
KEK, Ibaraki, Japan
B. Bolzon
The University of Liverpool, Liverpool, United Kingdom
B. Bolzon, T. Lefèvre, S. Mazzoni
CERN, Geneva, Switzerland

Transverse electron beam diagnostics is crucial for stable and reliable operation of the future electron-positron linear colliders such as CLIC or Higgs Factory. The-state-of-the-art in transverse beam diagnostics is based on the laser-wire technology. However, it requires a high power laser significantly increases the cost of the laser-wire system. Therefore, a simpler and relatively inexpensive method is required. A beam profile monitor based on Optical Transition Radiation (OTR) is very promising. The resolution of conventional OTR monitor is defined by a root-mean-square of the so-called Point Spread Function (PSF). In optical wavelength range the resolution is diffraction limited down to a few micrometers. However, in * we demonstrated that the OTR PSF has a structure which visibility can be used to monitor vertical beam size with sub-micrometer resolution. In this report we shall represent the recent experimental results of a micron-scale beam size measurement. We shall describe the entire method including calibration procedure, new analysis, and calculation of uncertainties. We shall discuss the hardware status and future plans.
* P. Karataev et al., Physical Review Letters 107, 174801 (2011).

Slides WEAL2 [5.120 MB]

WEPF03

Scintillating Screen Monitors for Transverse Electron Beam Profile Diagnostics at the European XFEL

electron, XFEL, transverse, DESY

807

Ch. Wiebers, M. Holz, G. Kube, D. Nölle, G. Priebe, H.-Ch. Schröder
DESY, Hamburg, Germany

Transverse beam profile diagnostics in modern electron linear accelerators like FELs or injector LINACs are mainly based on optical transition radiation (OTR) as standard technique which is observed in backward direction when a charged particle beam crosses the boundary between two media with different dielectric properties. The experience from modern LINAC based 4th generation light sources shows that OTR diagnostics might fail because of coherence effects in the OTR emission process. As a consequence, for the European XFEL which is currently under construction in Hamburg, transverse beam profile measurements are based on scintillating screen monitors. The LYSO:Ce screens are oriented such that coherent OTR generated at the screen boundaries will be geometrically suppressed. An additional advantage is that the imaging optics operate in Scheimpflug condition thus adjusting the plane of sharp focus with respect to the CCD chip and significantly increasing the apparent depth of field. This report gives an overview of the measuring principle and the monitor setup together with results of laboratory test measurements and a first prototype test at FLASH (DESY, Hamburg).

WEPF18

Zemax Simulations of Diffraction and Transition Radiation

simulation, radiation, target, electron

852

T. Aumeyr, P. Karataev
JAI, Egham, Surrey, United Kingdom
M.G. Billing
Cornell University (CLASSE), Cornell Laboratory for Accelerator-Based Sciences and Education, Ithaca, New York, USA
L.M. Bobb, B. Bolzon, T. Lefèvre, S. Mazzoni
CERN, Geneva, Switzerland

Diffraction Radiation (DR) and Transition Radiation (TR) are produced when a relativistic charged particle moves in the vicinity of a medium or through a medium respectively. The target atoms are polarised by the electric field of the charged particle, which then oscillate thus emitting radiation with a very broad spectrum. The spatial-spectral properties of DR/TR are sensitive to various electron beam parameters. Several projects aim to measure the transverse (vertical) beam size using DR or TR. This paper reports on how numerical simulations using Zemax can be used to study such a system.

Poster WEPF18 [0.573 MB]

WEPF23

Beam Diagnostics R&D within oPAC

radiation, diagnostics, transverse, simulation

864

C.P. Welsch
Cockcroft Institute, Warrington, Cheshire, United Kingdom
C.P. Welsch
The University of Liverpool, Liverpool, United Kingdom

Funding: oPAC is funded by the European Commission under Grant Agreement Number 289485.
Optimization of particle accelerators by combining research into beam physics, beam instrumentation, accelerator control systems and numerical simulation studies is the goal of the oPAC project. Supported with 6 Million Euros by the European Union, the network is one of the largest-ever Initial Training Networks. During the project's four year duration 22 fellows will be trained and a very broad international training program, consisting of schools, topical workshops and conferences will be organized by a consortium of currently more than 30 partner institutions. In this contribution, we will give an overview of oPAC's broad beam diagnostics R&D program, comprising absolute beam intensity measurements for low energy beams, beam diagnostics for synchrotron light sources, cyrogenic beam loss monitors, beam halo monitoring and 3D dose measurements as part of intensity modulated radiotherapy treatment. We will also summarize past oPAC events and give an outlook on future events.