IBIC2013 - List of Keywords (photon)

Paper	Title	Other Keywords	Page
MOPC10	Optimization of NSLS-II Blade X-ray Beam Position Monitors: From Photoemission Type to Diamond Detector	undulator, DIAMOND, radiation, beam-position	67
	P. Ilinski BNL, Upton, Long Island, New York, USA
	Optimization of blade type X-ray Beam Position Monitors (XBPM) was performed for NSLS-II undulator IVU20. Blade material, conﬁguration and operation principle were analyzed. Optimization is based on calculation of the XBPM signal spatial distribution. Along with standard photo-emission blades, Diamond Detector Blade (DDB) was examined as XBPM signal source. Analyses revealed, that Diamond Detector Blade XBPM would allow to overcome drawbacks of the photo-emission type XBPMs.

MOPF06	Beam Profile Monitors at REGAE	electron, diagnostics, optics, SNR	212
	H. Delsim-Hashemi, K. Flöttmann DESY, Hamburg, Germany S. Bayesteh Uni HH, Hamburg, Germany
	A new linac is commissioned at DESY mainly as the electron source for femtosecond electron diffraction facility REGAE (Relativistic Electron Gun for Atomic Exploration). REGAE enables studies on structural dynamics of atomic transition states occurring in the sub-hundred femtosecond time-scale. REGAE comprises a photo-cathode gun followed by normal conducting 1.5 cell rf-cavity to provide sub pC electron-bunches of 2-5 MeV with a coherence length of 30nm. In order to produce and maintain such electron bunches, sophisticated single-shot diagnostics are desired e.g. emittance, energy, energy-spread and bunch-length measurement. REGAE rep-rate can be up to 50 Hz. This relatively high rep-rate makes it more challenging to deal with low intensity detection especially in single-shot mode. In this contribution the conceptual ideas, realization and results of transversal diagnostics will be presented.

MOPF16	Sub-Micrometre Resolution Laserwire Transverse Beam Size Measurement System	laser, electron, transverse, OTR	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.

MOPF20	Bunch Purity Measurement for BEPCII	synchrotron, synchrotron-radiation, radiation, electron	252
	H. Jun, J.S. Cao, J.H. Junhui IHEP, Beijing, People's Republic of China
	The bunch purity is very important for time-resolved experiments. It is determined by the quality of the injection system and Touschek effect. The Beijing Electron-Positron Collider (BEPC) II was constructed for both high energy physics (HEP) and synchrotron radiation (SR) researches. It can be operated in the colliding mode and synchrotron radiation mode. It is planned to measure the beam quality in a short time of several minutes by using a timecorrelated single photon counting method. The method has a time resolution of 450 ps and a dynamic range of five orders of magnitude. In this paper, we describe our experimental set up and give a series of test results for colliding mode. We plan to set up a system which can kick out the unwanted bunches in the next stage.

TUPC10	Operation of Diamond Light Source XBPMs with Zero Bias	electron, DIAMOND, synchrotron, beam-position	376
	C. Bloomer, G. Rehm Diamond, Oxfordshire, United Kingdom
	Tungsten blade X-ray Beam Position Monitors (XBPMs) have been used at Diamond Light Source since 2007, however a long-standing problem with these devices has been the growth of leakage current through the ceramic insulation within the XBPMs over time, often becoming greater than 10% of the signal current after a few years of operation. The growth of these leakage currents has been found to be exacerbated by the application of a negative bias (-70V) to the tungsten blades, a bias suggested for optimum position sensitivity. This bias is applied in order to accelerate free electrons away from the surface of the blades and to prevent cross-talk, however, we have found that the operation of the XBPMs without bias has negligible impact on our measurements. Removal of the bias has been found to prevent the growth of leakage currents over time, and can also significantly reduce the cost of our signal acquisition by removing the need for a low-current amplifier with a bias supply.
	Poster TUPC10 [0.455 MB]

TUPC47	Simulation for Radiation Field Caused by Beam Loss of C-ADS Injector II	proton, beam-losses, electron, radiation	489
	G. Ren, W. Li, Y. Li USTC/NSRL, Hefei, Anhui, People's Republic of China M. Zeng Tsinghua University, Beijing, People's Republic of China
	CADS is a Chinese ADS(Accelerator Driven Sub-critical System) project. Its injector is a high current, full superconducting proton accelerator. For such a facility, a BLM system is necessary, especially in low energy segments. This paper presents some basic simulation for 10MeV proton by Monte Carlo program FLUKA, as well as the distributions we got about different secondary particles in three aspects: angular, energy spectrum and current. These results are helpful to select the detector type and its location, determine its dynamic range matching different requirements for both fast and slow beam loss. This paper also analyzes the major impact of the background, such as superconducting cavity X radiation and radiation caused by material activation. This work is meaningful in BLM system research.

TUPF17	Phase Space Measurement using X-ray Pinhole Camera at SSRF	emittance, storage-ring, quadrupole, radiation	539
	K.R. Ye, J. Chen, Z.C. Chen, G.Q. Huang, Y.B. Leng, L.Y. Yu, W.M. Zhou SINAP, Shanghai, People's Republic of China
	Since 2009 an X-ray pinhole camera that has been used to present the transverse beam size on diagnostic beamline of the storage ring in Shanghai Synchrotron Radiation Facility (SSRF). Transverse beam profiles in the real(x,y) and phase(Y,Y’) spaces are obtained by an X-ray pinhole camera sensitive by moving one pinhole. The large amount of collected data has allowed a detailed reconstruction of the transverse phase space evolution in this paper. An image on a fluorescent screen is observed by a CCD camera，digitized and stored, then the phase space and the real space profiles are reconstructed．A non-linear least square program fits the resultant profiles to a vertical dimensional Gaussian distributions to derive the phase space and emittances for SSRF storage ring．

TUPF18	Vertical Undulator Emittance Measurement: A Statistical Approach	undulator, emittance, electron, radiation	543
	K.P. Wootton, R.P. Rassool The University of Melbourne, Melbourne, Australia M.J. Boland, B.C.C. Cowie, R.T. Dowd SLSA, Clayton, Australia
	Direct measurement of low vertical emittance in storage rings is typically achieved via interferometric techniques. Proof of low vertical emittance is demonstrated by the measurement of a null radiation field, which is also the crux of the vertical undulator emittance measurement. Here we present strategies to improve the sensitivity to low vertical emittance beams. We move away from photon spectrum analysis to a statistical analysis of undulator radiation, showing the measured increase in signal-to-background. Reproducing simulations of previous work, we demonstrate that photon beam polarisation extends the linearity of the technique by several decades in emittance. These statistical and polarisation improvements to the signal-to-background allow realistic measurement of smallest vertical emittance.
	Poster TUPF18 [2.090 MB]

TUPF19	APPLE-II Undulator Magnetic Fields Characterised from Undulator Radiation	undulator, radiation, emittance, insertion	546
	K.P. Wootton, R.P. Rassool The University of Melbourne, Melbourne, Australia M.J. Boland, B.C.C. Cowie SLSA, Clayton, Australia
	The spatial profile of APPLE-II undulator radiation has been measured at high undulator deflection parameter, high harmonic and very small emittance. Undulators are typically designed to operate with small deflection parameter to push the fundamental mode to high photon energies. This unusual choice of parameters is desirable for measurement of vertical emittance with a vertical undulator. We present 1-D and 2-D measured profiles of undulator radiation, and show that this is reproduced in numerical models using the measured magnetic field of the insertion device. Importantly these measurements confirm that for these parameters, the spatial intensity distribution departs significantly from usual Gaussian approximations, instead resembling a double-slit diffraction pattern. This could be an important consideration for photon beamlines of ultimate storage ring light sources.
	Poster TUPF19 [2.364 MB]

WEAL1	Large Aperture X-ray Monitors for Beam Profile Diagnostics	optics, emittance, undulator, diagnostics	608
	C.A. Thomas, G. Rehm Diamond, Oxfordshire, United Kingdom F. Ewald ESRF, Grenoble, France J.W. Flanagan KEK, Ibaraki, Japan
	Emittance is one of the main characteristic properties of a beam of particles in an accelerator, and it is measured generally by means of the particle beam profile. In particular, when the beam of particles is emitting an X-ray photon beam, a non perturbative way of measuring the particle beam profile is to image it using the emitted X-ray photon beam. Over the years, numerous X-ray imaging methods have been developed, fulfilling the requirements imposed by a particle beam becoming smaller, and approaching micron size for electron beam machine with vertical emittance of the order of 1pm-rad. In this paper, we will first recall the properties of the X-ray photon as function of source and its properties. From this we will derive some natural definition of a large aperture X-ray imaging system. We will then use this selection criterion to select a number of X-ray imaging devices used as a beam profile diagnostics in an attempt to give an overview of what has been achieved and what is possible to achieve with the selected devices.
	Slides WEAL1 [7.499 MB]

WEPC20	Bunch Extension Monitor for LINAC of SPIRAL2 facility	linac, ion, MCP, diagnostics	720
	R.V. Revenko, J.L. Vignet GANIL, Caen, France
	Funding: This work is funded in frame of CRISP project. Measurements of the bunch longitudinal shape of beam particles are crucial for optimization and control of the LINAC beam parameters and maximization of its integrated luminosity. The non-interceptive bunch extension monitor for LINAC of SPIRAL2 facility is being developed at GANIL. The five bunch extension monitors are to be installed on the entrance of LINAC between superconducting cavities. The principle of monitor operation is based on registration of x-rays induced by ions of accelerator beam and emitted from thin tungsten wire. The monitor consists of two parts: system for wire insertion and positioning and x-ray detector based on microchannel plates. The prototype of detector has been developed and was tested using protons and heavy ions beams.
	Poster WEPC20 [9.366 MB]

WEPC43	Update on Beam Loss Monitoring at CTF3 for CLIC	CLIC, DIAMOND, beam-losses, quadrupole	787
	L.J. Devlin, S. Mallows, C.P. Welsch, E.N. del Busto Cockcroft Institute, Warrington, Cheshire, United Kingdom E. Branger Linköping University, Linköping, Sweden L.J. Devlin, S. Mallows, C.P. Welsch, E.N. del Busto The University of Liverpool, Liverpool, United Kingdom E. Effinger, E.B. Holzer, S. Mallows, E.N. del Busto CERN, Geneva, Switzerland
	Funding: Work supported by STFC Cockcroft Institute Core Grant No. ST/G008248/1 The primary role of the beam loss monitoring (BLM) system for the compact linear collider (CLIC) study is to work within the machine protection system. Due to the size of the CLIC facility, a BLM that covers large distances along the beamline is highly desirable, in particular for the CLIC drive beam decelerators, which would alternatively require some ~40,000 localised monitors. Therefore, an optical fiber BLM system is currently under investigation which can cover large sections of beamline at a time. A multimode fiber has been installed along the Test Beam Line at the CLIC test facility (CTF3) where the detection principle is based on the production of Cherenkov photons within the fiber resulting from beam loss and their subsequent transport along the fiber where they are then detected at the fiber ends using silicon photomultipliers. Several additional monitors including ACEMs, PEP-II and diamond detectors have also been installed. In this contribution the first results from the BLMs are presented, comparisons of the signals from each BLM are made and the possible achievable longitudinal resolution from the fiber BLM signal considering various loss patterns is discussed.

WEPF11	Emittance Measurement Using X-Ray Lenses at the ESRF	emittance, electron, dipole, lattice	833
	F. Ewald, J.C. Biasci, L. Farvacque, K.B. Scheidt ESRF, Grenoble, France
	During the year 2011, X-ray lenses were tested as an alternative way of emittance measurement in the ESRF storage ring. Following these tests it was decided to install a new bending magnet diagnostics beam port dedicated primarily to a permanent emittance measurement using X-ray lens imaging. The new beam port is equipped with a thin (0.6 mm) double CVD diamond window instead of 3 mm aluminium used at the pinhole beam ports. This increases the X-ray transmission, especially at low energies. The imaging and emittance measurement using aluminium lenses is discussed in comparison to the emittance measurement based on pinhole imaging. Although the principle works correctly, the setup presents different practical difficulties, such as low signal intensity and heat load.

WEPF12	Characterisation of Al-Compound Refractive Lenses for X-Rays	ESRF, LEFT, emittance, dipole	837
	F. Ewald, J.C. Biasci ESRF, Grenoble, France
	We report on measurements of the surface quality (shape) of aluminium compound refractive lenses using a thin collimated X-ray beam from one of our bending magnet diagnostics beam ports. Two types of lenses were tested for overall radius of curvature, surface quality and thickness: commercially available lenses (RWTH Aachen), and lenses of the same type manufactured at the ESRF. The different surface qualities can be readily discerned with our relatively simple setup. While the technique should be improved for more precise results, it already shows clearly the imperfect surface structure of the ESRF lenses. The image quality of the beam, however, is not affected to a visible extent in our emittance measurement setup at vertical emittances of typically ~ 6 pm.

WEPF36	X-ray Cherenkov Radiation as a Source for Relativistic Charged Particle Beam Diagnostics	radiation, polarization, electron, target	910
	A.S. Konkov, A.S. Gogolev, A. Potylitsyn TPU, Tomsk, Russia P. Karataev Royal Holloway, University of London, Surrey, United Kingdom
	Funding: The work was partially supported by Russian Ministry of Science and Education within the grant No. 14.B37.21.0912. Recent progress in development of accelerator technology for future linear colliders and X-ray free electron lasers has generated an interest in developing novel diagnostics equipment with resolution surpassing the unique beam parameters. Cherenkov radiation (CR) in the X-ray region in the vicinity of the absorption edges is one of the promising sources for relativistic charged particle beam diagnostics. In this work we have demonstrated CR characteristics in the X-ray region significantly depend on the energy of the emitted photons, because the CR is only generated in the frequency region in the vicinity of the atomic absorption edges, where the well-known Cherenkov condition is work. This peculiarity can be explained by resonance behaviour of the permittivity in the frequency range. It will result in the fact that the CR will stand out of any other types of polarisation radiation both on intensity and shape of angular distribution giving a unique opportunity to apply this phenomenon for charged particle beam diagnostics.
	Poster WEPF36 [42.675 MB]

THAL3	Charge Distribution Measurements at ALBA	synchrotron, electron, BPM, injection	925
	L. Torino, U. Iriso CELLS-ALBA Synchrotron, Cerdanyola del Vallès, Spain
	Two different set-ups are used to perform quantitative measurements of the charge distribution at ALBA. The first consists in a real-time analysis of data coming from the Fast Current Transformer or from the buttons of a Beam Position Monitor installed in the Storage Ring. The second is performed at the diagnostic visible beamline Xanadu, using a Photomultiplier that measures the temporal distribution of synchrotron light. In both cases a quantitative estimation of the charge distribution is obtained after a dedicated data treatment and beam current measurements from the DCCT. We compare results with both methods, and discuss differences and limitations with respect to bunch purity measurements with the Time Correlated Single Photon Counting technique.
	Slides THAL3 [15.369 MB]

Paper

Title

Other Keywords

Page

MOPC10

Optimization of NSLS-II Blade X-ray Beam Position Monitors: From Photoemission Type to Diamond Detector

undulator, DIAMOND, radiation, beam-position

67

P. Ilinski
BNL, Upton, Long Island, New York, USA

Optimization of blade type X-ray Beam Position Monitors (XBPM) was performed for NSLS-II undulator IVU20. Blade material, conﬁguration and operation principle were analyzed. Optimization is based on calculation of the XBPM signal spatial distribution. Along with standard photo-emission blades, Diamond Detector Blade (DDB) was examined as XBPM signal source. Analyses revealed, that Diamond Detector Blade XBPM would allow to overcome drawbacks of the photo-emission type XBPMs.

MOPF06

Beam Profile Monitors at REGAE

electron, diagnostics, optics, SNR

212

H. Delsim-Hashemi, K. Flöttmann
DESY, Hamburg, Germany
S. Bayesteh
Uni HH, Hamburg, Germany

A new linac is commissioned at DESY mainly as the electron source for femtosecond electron diffraction facility REGAE (Relativistic Electron Gun for Atomic Exploration). REGAE enables studies on structural dynamics of atomic transition states occurring in the sub-hundred femtosecond time-scale. REGAE comprises a photo-cathode gun followed by normal conducting 1.5 cell rf-cavity to provide sub pC electron-bunches of 2-5 MeV with a coherence length of 30nm. In order to produce and maintain such electron bunches, sophisticated single-shot diagnostics are desired e.g. emittance, energy, energy-spread and bunch-length measurement. REGAE rep-rate can be up to 50 Hz. This relatively high rep-rate makes it more challenging to deal with low intensity detection especially in single-shot mode. In this contribution the conceptual ideas, realization and results of transversal diagnostics will be presented.

MOPF16

Sub-Micrometre Resolution Laserwire Transverse Beam Size Measurement System

laser, electron, transverse, OTR

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.

MOPF20

Bunch Purity Measurement for BEPCII

synchrotron, synchrotron-radiation, radiation, electron

252

H. Jun, J.S. Cao, J.H. Junhui
IHEP, Beijing, People's Republic of China

The bunch purity is very important for time-resolved experiments. It is determined by the quality of the injection system and Touschek effect. The Beijing Electron-Positron Collider (BEPC) II was constructed for both high energy physics (HEP) and synchrotron radiation (SR) researches. It can be operated in the colliding mode and synchrotron radiation mode. It is planned to measure the beam quality in a short time of several minutes by using a timecorrelated single photon counting method. The method has a time resolution of 450 ps and a dynamic range of five orders of magnitude. In this paper, we describe our experimental set up and give a series of test results for colliding mode. We plan to set up a system which can kick out the unwanted bunches in the next stage.

TUPC10

Operation of Diamond Light Source XBPMs with Zero Bias

electron, DIAMOND, synchrotron, beam-position

376

C. Bloomer, G. Rehm
Diamond, Oxfordshire, United Kingdom

Tungsten blade X-ray Beam Position Monitors (XBPMs) have been used at Diamond Light Source since 2007, however a long-standing problem with these devices has been the growth of leakage current through the ceramic insulation within the XBPMs over time, often becoming greater than 10% of the signal current after a few years of operation. The growth of these leakage currents has been found to be exacerbated by the application of a negative bias (-70V) to the tungsten blades, a bias suggested for optimum position sensitivity. This bias is applied in order to accelerate free electrons away from the surface of the blades and to prevent cross-talk, however, we have found that the operation of the XBPMs without bias has negligible impact on our measurements. Removal of the bias has been found to prevent the growth of leakage currents over time, and can also significantly reduce the cost of our signal acquisition by removing the need for a low-current amplifier with a bias supply.

Poster TUPC10 [0.455 MB]

TUPC47

Simulation for Radiation Field Caused by Beam Loss of C-ADS Injector II

proton, beam-losses, electron, radiation

489

G. Ren, W. Li, Y. Li
USTC/NSRL, Hefei, Anhui, People's Republic of China
M. Zeng
Tsinghua University, Beijing, People's Republic of China

CADS is a Chinese ADS(Accelerator Driven Sub-critical System) project. Its injector is a high current, full superconducting proton accelerator. For such a facility, a BLM system is necessary, especially in low energy segments. This paper presents some basic simulation for 10MeV proton by Monte Carlo program FLUKA, as well as the distributions we got about different secondary particles in three aspects: angular, energy spectrum and current. These results are helpful to select the detector type and its location, determine its dynamic range matching different requirements for both fast and slow beam loss. This paper also analyzes the major impact of the background, such as superconducting cavity X radiation and radiation caused by material activation. This work is meaningful in BLM system research.

TUPF17

Phase Space Measurement using X-ray Pinhole Camera at SSRF

emittance, storage-ring, quadrupole, radiation

539

K.R. Ye, J. Chen, Z.C. Chen, G.Q. Huang, Y.B. Leng, L.Y. Yu, W.M. Zhou
SINAP, Shanghai, People's Republic of China

Since 2009 an X-ray pinhole camera that has been used to present the transverse beam size on diagnostic beamline of the storage ring in Shanghai Synchrotron Radiation Facility (SSRF). Transverse beam profiles in the real(x,y) and phase(Y,Y’) spaces are obtained by an X-ray pinhole camera sensitive by moving one pinhole. The large amount of collected data has allowed a detailed reconstruction of the transverse phase space evolution in this paper. An image on a fluorescent screen is observed by a CCD camera，digitized and stored, then the phase space and the real space profiles are reconstructed．A non-linear least square program fits the resultant profiles to a vertical dimensional Gaussian distributions to derive the phase space and emittances for SSRF storage ring．

TUPF18

Vertical Undulator Emittance Measurement: A Statistical Approach

undulator, emittance, electron, radiation

543

K.P. Wootton, R.P. Rassool
The University of Melbourne, Melbourne, Australia
M.J. Boland, B.C.C. Cowie, R.T. Dowd
SLSA, Clayton, Australia

Direct measurement of low vertical emittance in storage rings is typically achieved via interferometric techniques. Proof of low vertical emittance is demonstrated by the measurement of a null radiation field, which is also the crux of the vertical undulator emittance measurement. Here we present strategies to improve the sensitivity to low vertical emittance beams. We move away from photon spectrum analysis to a statistical analysis of undulator radiation, showing the measured increase in signal-to-background. Reproducing simulations of previous work, we demonstrate that photon beam polarisation extends the linearity of the technique by several decades in emittance. These statistical and polarisation improvements to the signal-to-background allow realistic measurement of smallest vertical emittance.

Poster TUPF18 [2.090 MB]

TUPF19

APPLE-II Undulator Magnetic Fields Characterised from Undulator Radiation

undulator, radiation, emittance, insertion

546

K.P. Wootton, R.P. Rassool
The University of Melbourne, Melbourne, Australia
M.J. Boland, B.C.C. Cowie
SLSA, Clayton, Australia

The spatial profile of APPLE-II undulator radiation has been measured at high undulator deflection parameter, high harmonic and very small emittance. Undulators are typically designed to operate with small deflection parameter to push the fundamental mode to high photon energies. This unusual choice of parameters is desirable for measurement of vertical emittance with a vertical undulator. We present 1-D and 2-D measured profiles of undulator radiation, and show that this is reproduced in numerical models using the measured magnetic field of the insertion device. Importantly these measurements confirm that for these parameters, the spatial intensity distribution departs significantly from usual Gaussian approximations, instead resembling a double-slit diffraction pattern. This could be an important consideration for photon beamlines of ultimate storage ring light sources.

Poster TUPF19 [2.364 MB]

WEAL1

Large Aperture X-ray Monitors for Beam Profile Diagnostics

optics, emittance, undulator, diagnostics

608

C.A. Thomas, G. Rehm
Diamond, Oxfordshire, United Kingdom
F. Ewald
ESRF, Grenoble, France
J.W. Flanagan
KEK, Ibaraki, Japan

Emittance is one of the main characteristic properties of a beam of particles in an accelerator, and it is measured generally by means of the particle beam profile. In particular, when the beam of particles is emitting an X-ray photon beam, a non perturbative way of measuring the particle beam profile is to image it using the emitted X-ray photon beam. Over the years, numerous X-ray imaging methods have been developed, fulfilling the requirements imposed by a particle beam becoming smaller, and approaching micron size for electron beam machine with vertical emittance of the order of 1pm-rad. In this paper, we will first recall the properties of the X-ray photon as function of source and its properties. From this we will derive some natural definition of a large aperture X-ray imaging system. We will then use this selection criterion to select a number of X-ray imaging devices used as a beam profile diagnostics in an attempt to give an overview of what has been achieved and what is possible to achieve with the selected devices.

Slides WEAL1 [7.499 MB]

WEPC20

Bunch Extension Monitor for LINAC of SPIRAL2 facility

linac, ion, MCP, diagnostics

720

R.V. Revenko, J.L. Vignet
GANIL, Caen, France

Funding: This work is funded in frame of CRISP project.
Measurements of the bunch longitudinal shape of beam particles are crucial for optimization and control of the LINAC beam parameters and maximization of its integrated luminosity. The non-interceptive bunch extension monitor for LINAC of SPIRAL2 facility is being developed at GANIL. The five bunch extension monitors are to be installed on the entrance of LINAC between superconducting cavities. The principle of monitor operation is based on registration of x-rays induced by ions of accelerator beam and emitted from thin tungsten wire. The monitor consists of two parts: system for wire insertion and positioning and x-ray detector based on microchannel plates. The prototype of detector has been developed and was tested using protons and heavy ions beams.

Poster WEPC20 [9.366 MB]

WEPC43

Update on Beam Loss Monitoring at CTF3 for CLIC

CLIC, DIAMOND, beam-losses, quadrupole

787

L.J. Devlin, S. Mallows, C.P. Welsch, E.N. del Busto
Cockcroft Institute, Warrington, Cheshire, United Kingdom
E. Branger
Linköping University, Linköping, Sweden
L.J. Devlin, S. Mallows, C.P. Welsch, E.N. del Busto
The University of Liverpool, Liverpool, United Kingdom
E. Effinger, E.B. Holzer, S. Mallows, E.N. del Busto
CERN, Geneva, Switzerland

Funding: Work supported by STFC Cockcroft Institute Core Grant No. ST/G008248/1
The primary role of the beam loss monitoring (BLM) system for the compact linear collider (CLIC) study is to work within the machine protection system. Due to the size of the CLIC facility, a BLM that covers large distances along the beamline is highly desirable, in particular for the CLIC drive beam decelerators, which would alternatively require some ~40,000 localised monitors. Therefore, an optical fiber BLM system is currently under investigation which can cover large sections of beamline at a time. A multimode fiber has been installed along the Test Beam Line at the CLIC test facility (CTF3) where the detection principle is based on the production of Cherenkov photons within the fiber resulting from beam loss and their subsequent transport along the fiber where they are then detected at the fiber ends using silicon photomultipliers. Several additional monitors including ACEMs, PEP-II and diamond detectors have also been installed. In this contribution the first results from the BLMs are presented, comparisons of the signals from each BLM are made and the possible achievable longitudinal resolution from the fiber BLM signal considering various loss patterns is discussed.

WEPF11

Emittance Measurement Using X-Ray Lenses at the ESRF

emittance, electron, dipole, lattice

833

F. Ewald, J.C. Biasci, L. Farvacque, K.B. Scheidt
ESRF, Grenoble, France

During the year 2011, X-ray lenses were tested as an alternative way of emittance measurement in the ESRF storage ring. Following these tests it was decided to install a new bending magnet diagnostics beam port dedicated primarily to a permanent emittance measurement using X-ray lens imaging. The new beam port is equipped with a thin (0.6 mm) double CVD diamond window instead of 3 mm aluminium used at the pinhole beam ports. This increases the X-ray transmission, especially at low energies. The imaging and emittance measurement using aluminium lenses is discussed in comparison to the emittance measurement based on pinhole imaging. Although the principle works correctly, the setup presents different practical difficulties, such as low signal intensity and heat load.

WEPF12

Characterisation of Al-Compound Refractive Lenses for X-Rays

ESRF, LEFT, emittance, dipole

837

F. Ewald, J.C. Biasci
ESRF, Grenoble, France

We report on measurements of the surface quality (shape) of aluminium compound refractive lenses using a thin collimated X-ray beam from one of our bending magnet diagnostics beam ports. Two types of lenses were tested for overall radius of curvature, surface quality and thickness: commercially available lenses (RWTH Aachen), and lenses of the same type manufactured at the ESRF. The different surface qualities can be readily discerned with our relatively simple setup. While the technique should be improved for more precise results, it already shows clearly the imperfect surface structure of the ESRF lenses. The image quality of the beam, however, is not affected to a visible extent in our emittance measurement setup at vertical emittances of typically ~ 6 pm.

WEPF36

X-ray Cherenkov Radiation as a Source for Relativistic Charged Particle Beam Diagnostics

radiation, polarization, electron, target

910

A.S. Konkov, A.S. Gogolev, A. Potylitsyn
TPU, Tomsk, Russia
P. Karataev
Royal Holloway, University of London, Surrey, United Kingdom

Funding: The work was partially supported by Russian Ministry of Science and Education within the grant No. 14.B37.21.0912.
Recent progress in development of accelerator technology for future linear colliders and X-ray free electron lasers has generated an interest in developing novel diagnostics equipment with resolution surpassing the unique beam parameters. Cherenkov radiation (CR) in the X-ray region in the vicinity of the absorption edges is one of the promising sources for relativistic charged particle beam diagnostics. In this work we have demonstrated CR characteristics in the X-ray region significantly depend on the energy of the emitted photons, because the CR is only generated in the frequency region in the vicinity of the atomic absorption edges, where the well-known Cherenkov condition is work. This peculiarity can be explained by resonance behaviour of the permittivity in the frequency range. It will result in the fact that the CR will stand out of any other types of polarisation radiation both on intensity and shape of angular distribution giving a unique opportunity to apply this phenomenon for charged particle beam diagnostics.

Poster WEPF36 [42.675 MB]

THAL3

Charge Distribution Measurements at ALBA

synchrotron, electron, BPM, injection

925

L. Torino, U. Iriso
CELLS-ALBA Synchrotron, Cerdanyola del Vallès, Spain

Two different set-ups are used to perform quantitative measurements of the charge distribution at ALBA. The first consists in a real-time analysis of data coming from the Fast Current Transformer or from the buttons of a Beam Position Monitor installed in the Storage Ring. The second is performed at the diagnostic visible beamline Xanadu, using a Photomultiplier that measures the temporal distribution of synchrotron light. In both cases a quantitative estimation of the charge distribution is obtained after a dedicated data treatment and beam current measurements from the DCCT. We compare results with both methods, and discuss differences and limitations with respect to bunch purity measurements with the Time Correlated Single Photon Counting technique.

Slides THAL3 [15.369 MB]