IBIC2012 - List of Keywords (coupling)

Paper	Title	Other Keywords	Page
MOPA01	Design Study of the Striplines for the Extraction Kicker of the CLIC Damping Rings	impedance, kicker, simulation, damping	47
	C. Belver-Aguilar, A. Faus-Golfe IFIC, Valencia, Spain M.J. Barnes CERN, Geneva, Switzerland F. Toral CIEMAT, Madrid, Spain
	Pre-Damping Rings (PDRs) and Damping Rings (DRs) are needed to reduce the beam emittance and, therefore, to achieve the luminosity requirements for the CLIC main linac. Several stripline kicker systems will be used to inject and extract the beam from the PDRs and DRs. Results of initial studies of the stripline cross-section and the beam coupling impedance, for a non-tapered beam pipe, have previously been reported. In this paper, we present the analysis to study the final choice of the cross-section design, based on impedance matching and field inhomogeneity requirements, the power reflected in the transition between an electrode and the input coaxial feedthrough, and the predicted beam coupling impedance. Mechanical tolerances for the stripline manufacturing process are presently being studied. The striplines are planned to be prototyped by December 2012.

MOPA18	A Prototype Cavity Beam Position Monitor for the CLIC Main Beam	cavity, electronics, dipole, factory	95
	F.J. Cullinan, S.T. Boogert, N.Y. Joshi, A. Lyapin JAI, Egham, Surrey, United Kingdom D. Bastard, E. Calvo, N. Chritin, F. Guillot-Vignot, T. Lefèvre, L. Søby, M. Wendt CERN, Geneva, Switzerland A. Lunin, V.P. Yakovlev Fermilab, Batavia, USA S.R. Smith SLAC, Menlo Park, California, USA
	The Compact Linear Collider (CLIC) places unprecedented demands on its diagnostics systems. A large number of cavity beam position monitors (BPMs) throughout the main linac and beam delivery system must routinely perform with 50 nm spatial resolution. Multiple position measurements within a single 156~ns bunch train are also required. A prototype low-Q cavity beam position monitor has been designed and built to be tested on the CLIC Test Facility (CTF3) probe beam. This paper presents the latest measurements of the prototype cavity BPM and the design and simulation of the radio frequency (RF) signal processing electronics with regards to the final performance. Installation of the BPM in the CTF3 probe beamline is also discussed.

MOPA31	Design and Fabrication of the Stripline BPM at ESS-Bilbao	pick-up, controls, impedance, electronics	122
	S. Varnasseri, I. Arredondo, D. Belver, F.J. Bermejo, J. Feuchtwanger, N. Garmendia, P.J. González, L. Muguira ESS Bilbao, LEIOA, Spain V. Etxebarria, J. Jugo, J. Portilla University of the Basque Country, Faculty of Science and Technology, Bilbao, Spain
	A Stripline type BPM is designed and fabricated at ESSB. In order to compare, in the future, the functionality and response of the previous BPM capacitive pick-ups design with stripline, a design for stripline BPM is proposed. The design is based on travelling wave electrodes principles to detect the transverse position of the beam in the vacuum chamber. In the design of stripline setup, it has been considered to keep the comparison conditions with pick-ups as similar as possible. The length of strip electrodes is 200 mm and the coverage angle is 0.952 rad. The structure is rotationally pi/2 symmetric and the alignment of electrodes are pi/4, 3pi/, 5pi/4 and 7pi/4. The design is optimized for a frequency of 352 MHz, however it can function on a wide range of frequencies out coming from the measurement results. Striplines in general have well defined behavior even for low beta and low intensity beams as well as functionality at low and high frequencies. A report on the design and characteristics measurement of Stripline will be presented. The characteristics like frequency range, electrodes insulation, electrode response, sensitivities to beam power and position will be presented.

MOPA45	Study of Beam Length Measurement based on TM010 Mode	simulation, cavity, FEL, impedance	162
	R.X. Yuan, Y.B. Leng, L.Y. Yu, W.M. Zhou SINAP, Shanghai, People's Republic of China
	Beam length measurement in frequency domain is a familiar method, and the resolution is seriously limited by the system signal-noise-ratio (SNR) and the beam length measured. Usually this method can only obtain the resolution about ~10ps with beam length ~30ps when using signal from button or stripline BPM. But in FEL case, the beam length is the ps or sub-ps order. The paper discusses the probability of beam length measurement based on the TM010 mode in FEL case. When adopting High Order Mode(HOM) reject and system gain control, the system SNR can arrive at 110dB and the resolution can achieve 30fs with beam length ps or sub-ps.

MOPB72	First Measurements with Coded Aperture X-ray Monitor at the ATF2 Extraction Line	detector, extraction, optics, vacuum	237
	J.W. Flanagan, A. Arinaga, H. Fukuma, H. Ikeda, T.M. Mitsuhashi KEK, Ibaraki, Japan G.S. Varner University of Hawaii, Honolulu, HI, USA
	Funding: Kakenhi The ATF2 extraction line is used as a test-bed for technologies needed for the ILC final-focus region. An x-ray extraction beam line has been constructed at the final upstream bend before the extraction line straight section, for development and testing of optics and readout systems for a coded aperture-based imaging system. The x-ray monitor is expected to eventually be able to measure single-shot vertical bunch sizes down to a few microns in size at its source location in the ATF2 extraction line. Preliminary scanned measurements have been made with beams in the ~15 micron range, and it is planned to make more measurements with further-tuned beam, and with fast read-out electronics. The details of the layout, expected performance, and preliminary measurement results will be presented.

TUPA24	Design of Cavity BPM Pickups for SwissFEL	cavity, pick-up, undulator, linac	390
	F. Marcellini, B. Keil, M. Rohrer, M. Stadler, J. Stettler, D.M. Treyer PSI, Villigen PSI, Switzerland D. Lipka, D. Nölle, M. Pelzer, S. Vilcins DESY, Hamburg, Germany
	SwissFEL is a 0.1nm hard X-ray Free Electron Laser being built at PSI. A photocathode gun, S-band injector and C-band linac provide 2 bunches at 28ns spacing, 10-200pC charge, and 5.8GeV maximum energy. A fast distribution kicker will provide one bunch each to one hard X-ray and one soft X-ray undulator line. For linac and undulators, first prototypes of dual-resonator cavity BPM pickups have been designed and fabricated. The pickups were optimized for low charge and short bunch spacing in the linac. Design considerations, simulation and first test results will be reported.

TUPA25	Signal Transmission Characteristics in Stripline-Type Beam Position Monitor	impedance, electronics, positron, pick-up	394
	T. Suwada KEK, Ibaraki, Japan
	New stripline-type beam position monitor (BPM) system is under development at the KEKB injector linac in order to measure transverse beam positions with a high precision less than 10 micron meters towards the Super KEKB-factory (SKEKB) at KEK. During the KEKB operation, conventional stripline-type BPMs with a position resolution of 0.1 mm have been working well. However, the high-precision BPM system is strongly required for the SKEKB operation to stably accelerate single-bunch electron and positron beams with high bunch charges of ~5 nC/bunch, and also to keep the beam stability with higher brightness. The new stripline-type BPMs with large aperture compared with previously designed BPMs, which will be installed just after the positron production and capture section, have been designed. In this report, the basic design for fabricating the prototype stripline-type BPM, and, especially, theoretical analysis and experimental investigations on the signal propagation characteristics and performance along the stripling electrodes are described in detail on the base of a coupled-mode analysis of uniform coupled transmission lines.

TUPB70	The ATF2 Multi-OTR System: Studies and Design Improvements	emittance, target, operation, wakefield	505
	J. Alabau-Gonzalvo, C. Blanch Gutierrez, A. Faus-Golfe, J.J. García-Garrigós, J. Resta-López IFIC, Valencia, Spain J. Cruz, D.J. McCormick, G.R. White, M. Woodley SLAC, Menlo Park, California, USA
	Funding: Funding Agency: FPA2010-21456-C02-01 Work supported in part by Department of Energy Contract DE-AC02-76SF00515. A multi-Optical Transition Radiation system made of four stations has been installed in the extraction line of ATF2 and has been fully operational since September 2011. The system is being used routinely for beam size and emittance measurements as well as for coupling correction and energy spread measurements. In this paper we present the beam sizes and emittance measurements performed during 2012 runs as well as a detailed study of the experimental single-shot automated coupling correction and the comparison with the simulations. Wakefields problems experimented with the simultaneous measurement has been studied and will be solved by new target holders that will be installed in the next Fall 2012 run.

TUPB84	Storage Ring Tune Measurements using High-speed Metal-semiconductor-metal Photodetector	synchrotron, storage-ring, detector, electron	537
	S. Dawson, D.J. Peake, R.P. Rassool The University of Melbourne, Melbourne, Australia M.J. Boland ASCo, Clayton, Victoria, Australia R.J. Steinhagen CERN, Geneva, Switzerland
	Knowledge of the betatron tunes within a storage ring is important to prevent the creation of instabilities and maximise the lifetime of the stored current within the ring. Typical tune measurements excite the beam and measure the resulting motion over time using electromagnetic pickups. The novel measurement technique presented utilises high-speed MSM photodiodes in a balanced detector set-up to measure the vertical and horizontal betatron tunes. Radiation from a bending magnet consists of both visible light and X-rays. The visible light is separated from the X-rays with an optical chicane and focussed onto a pair of length-matched optical fibers each coupled to an MSM photodiode. The specialised biasing circuit for the photodiodes is constructed in a balanced detector configuration to emphasise any motion in the beam. Signal resulting from beam motion is amplified and digitised for analysis. Using this set-up the tunes for the storage ring at the Australian Synchrotron have been measured and verified with comparison to existing tune measurement technologies. The results from the new optical tune measurement system will be presented and discussed.

WECC03	Intensity Imbalance Optical Interferometer Beam Size Monitor	diagnostics, synchrotron, storage-ring, damping	566
	M.J. Boland ASCo, Clayton, Victoria, Australia T.M. Mitsuhashi, T. Naito KEK, Ibaraki, Japan K.P. Wootton The University of Melbourne, Melbourne, Australia
	The technique of measuring the beam size in a particle accelerator with an optical interferometer with the Mitsuhashi apparatus is well established and one of the only direct measurement techniques available. However, one of the limitations of the technique is the dynamic range and noise level of CCD cameras when measuring ultra low emittance beams and hence visibilities close to unity. A new design has been successfully tested to overcome these limitations by introducing a know intensity imbalance in one of the light paths of the interferometer. This modification reduces the visibility in a controlled way and lifts the measured interference pattern out of the noise level of the CCD, thus increasing the dynamic range of the apparatus. Results are presented from tests at the ATF2 at KEK and on the optical diagnostic beamline at the Australian Synchrotron storage ring.
	Slides WECC03 [2.383 MB]

THTA01	Beam Position Monitors for Circular Accelerators	pick-up, impedance, resonance, closed-orbit	590
	S. Hiramatsu KEK, Ibaraki, Japan
	The electrostatic induction type beam position monitors (BPMs) for circular accelerators such as proton synchrotrons and electron accumulation rings will be discussed. Discussions on the beam induced charge on the BPM pick-up electrodes, signal detection systems, and techniques of beam based alignment and beam based calibration will be given. For high beam current machines, the evaluation of the beam coupling impedance of BPM is an important issue to avoid the beam current limit by beam instabilities caused by BPM impedances. Another serious problem is the movement of BPMs by the thermal distortion of the beam pipe by high power synchrotron radiation. These problems will be also mentioned briefly.
	Slides THTA01 [6.252 MB]

Paper

Title

Other Keywords

Page

MOPA01

Design Study of the Striplines for the Extraction Kicker of the CLIC Damping Rings

impedance, kicker, simulation, damping

47

C. Belver-Aguilar, A. Faus-Golfe
IFIC, Valencia, Spain
M.J. Barnes
CERN, Geneva, Switzerland
F. Toral
CIEMAT, Madrid, Spain

Pre-Damping Rings (PDRs) and Damping Rings (DRs) are needed to reduce the beam emittance and, therefore, to achieve the luminosity requirements for the CLIC main linac. Several stripline kicker systems will be used to inject and extract the beam from the PDRs and DRs. Results of initial studies of the stripline cross-section and the beam coupling impedance, for a non-tapered beam pipe, have previously been reported. In this paper, we present the analysis to study the final choice of the cross-section design, based on impedance matching and field inhomogeneity requirements, the power reflected in the transition between an electrode and the input coaxial feedthrough, and the predicted beam coupling impedance. Mechanical tolerances for the stripline manufacturing process are presently being studied. The striplines are planned to be prototyped by December 2012.

MOPA18

A Prototype Cavity Beam Position Monitor for the CLIC Main Beam

cavity, electronics, dipole, factory

95

F.J. Cullinan, S.T. Boogert, N.Y. Joshi, A. Lyapin
JAI, Egham, Surrey, United Kingdom
D. Bastard, E. Calvo, N. Chritin, F. Guillot-Vignot, T. Lefèvre, L. Søby, M. Wendt
CERN, Geneva, Switzerland
A. Lunin, V.P. Yakovlev
Fermilab, Batavia, USA
S.R. Smith
SLAC, Menlo Park, California, USA

The Compact Linear Collider (CLIC) places unprecedented demands on its diagnostics systems. A large number of cavity beam position monitors (BPMs) throughout the main linac and beam delivery system must routinely perform with 50 nm spatial resolution. Multiple position measurements within a single 156~ns bunch train are also required. A prototype low-Q cavity beam position monitor has been designed and built to be tested on the CLIC Test Facility (CTF3) probe beam. This paper presents the latest measurements of the prototype cavity BPM and the design and simulation of the radio frequency (RF) signal processing electronics with regards to the final performance. Installation of the BPM in the CTF3 probe beamline is also discussed.

MOPA31

Design and Fabrication of the Stripline BPM at ESS-Bilbao

pick-up, controls, impedance, electronics

122

S. Varnasseri, I. Arredondo, D. Belver, F.J. Bermejo, J. Feuchtwanger, N. Garmendia, P.J. González, L. Muguira
ESS Bilbao, LEIOA, Spain
V. Etxebarria, J. Jugo, J. Portilla
University of the Basque Country, Faculty of Science and Technology, Bilbao, Spain

A Stripline type BPM is designed and fabricated at ESSB. In order to compare, in the future, the functionality and response of the previous BPM capacitive pick-ups design with stripline, a design for stripline BPM is proposed. The design is based on travelling wave electrodes principles to detect the transverse position of the beam in the vacuum chamber. In the design of stripline setup, it has been considered to keep the comparison conditions with pick-ups as similar as possible. The length of strip electrodes is 200 mm and the coverage angle is 0.952 rad. The structure is rotationally pi/2 symmetric and the alignment of electrodes are pi/4, 3pi/, 5pi/4 and 7pi/4. The design is optimized for a frequency of 352 MHz, however it can function on a wide range of frequencies out coming from the measurement results. Striplines in general have well defined behavior even for low beta and low intensity beams as well as functionality at low and high frequencies. A report on the design and characteristics measurement of Stripline will be presented. The characteristics like frequency range, electrodes insulation, electrode response, sensitivities to beam power and position will be presented.

MOPA45

Study of Beam Length Measurement based on TM010 Mode

simulation, cavity, FEL, impedance

162

R.X. Yuan, Y.B. Leng, L.Y. Yu, W.M. Zhou
SINAP, Shanghai, People's Republic of China

Beam length measurement in frequency domain is a familiar method, and the resolution is seriously limited by the system signal-noise-ratio (SNR) and the beam length measured. Usually this method can only obtain the resolution about ~10ps with beam length ~30ps when using signal from button or stripline BPM. But in FEL case, the beam length is the ps or sub-ps order. The paper discusses the probability of beam length measurement based on the TM010 mode in FEL case. When adopting High Order Mode(HOM) reject and system gain control, the system SNR can arrive at 110dB and the resolution can achieve 30fs with beam length ps or sub-ps.

MOPB72

First Measurements with Coded Aperture X-ray Monitor at the ATF2 Extraction Line

detector, extraction, optics, vacuum

237

J.W. Flanagan, A. Arinaga, H. Fukuma, H. Ikeda, T.M. Mitsuhashi
KEK, Ibaraki, Japan
G.S. Varner
University of Hawaii, Honolulu, HI, USA

Funding: Kakenhi
The ATF2 extraction line is used as a test-bed for technologies needed for the ILC final-focus region. An x-ray extraction beam line has been constructed at the final upstream bend before the extraction line straight section, for development and testing of optics and readout systems for a coded aperture-based imaging system. The x-ray monitor is expected to eventually be able to measure single-shot vertical bunch sizes down to a few microns in size at its source location in the ATF2 extraction line. Preliminary scanned measurements have been made with beams in the ~15 micron range, and it is planned to make more measurements with further-tuned beam, and with fast read-out electronics. The details of the layout, expected performance, and preliminary measurement results will be presented.

TUPA24

Design of Cavity BPM Pickups for SwissFEL

cavity, pick-up, undulator, linac

390

F. Marcellini, B. Keil, M. Rohrer, M. Stadler, J. Stettler, D.M. Treyer
PSI, Villigen PSI, Switzerland
D. Lipka, D. Nölle, M. Pelzer, S. Vilcins
DESY, Hamburg, Germany

SwissFEL is a 0.1nm hard X-ray Free Electron Laser being built at PSI. A photocathode gun, S-band injector and C-band linac provide 2 bunches at 28ns spacing, 10-200pC charge, and 5.8GeV maximum energy. A fast distribution kicker will provide one bunch each to one hard X-ray and one soft X-ray undulator line. For linac and undulators, first prototypes of dual-resonator cavity BPM pickups have been designed and fabricated. The pickups were optimized for low charge and short bunch spacing in the linac. Design considerations, simulation and first test results will be reported.

TUPA25

Signal Transmission Characteristics in Stripline-Type Beam Position Monitor

impedance, electronics, positron, pick-up

394

T. Suwada
KEK, Ibaraki, Japan

New stripline-type beam position monitor (BPM) system is under development at the KEKB injector linac in order to measure transverse beam positions with a high precision less than 10 micron meters towards the Super KEKB-factory (SKEKB) at KEK. During the KEKB operation, conventional stripline-type BPMs with a position resolution of 0.1 mm have been working well. However, the high-precision BPM system is strongly required for the SKEKB operation to stably accelerate single-bunch electron and positron beams with high bunch charges of ~5 nC/bunch, and also to keep the beam stability with higher brightness. The new stripline-type BPMs with large aperture compared with previously designed BPMs, which will be installed just after the positron production and capture section, have been designed. In this report, the basic design for fabricating the prototype stripline-type BPM, and, especially, theoretical analysis and experimental investigations on the signal propagation characteristics and performance along the stripling electrodes are described in detail on the base of a coupled-mode analysis of uniform coupled transmission lines.

TUPB70

The ATF2 Multi-OTR System: Studies and Design Improvements

emittance, target, operation, wakefield

505

J. Alabau-Gonzalvo, C. Blanch Gutierrez, A. Faus-Golfe, J.J. García-Garrigós, J. Resta-López
IFIC, Valencia, Spain
J. Cruz, D.J. McCormick, G.R. White, M. Woodley
SLAC, Menlo Park, California, USA

Funding: Funding Agency: FPA2010-21456-C02-01 Work supported in part by Department of Energy Contract DE-AC02-76SF00515.
A multi-Optical Transition Radiation system made of four stations has been installed in the extraction line of ATF2 and has been fully operational since September 2011. The system is being used routinely for beam size and emittance measurements as well as for coupling correction and energy spread measurements. In this paper we present the beam sizes and emittance measurements performed during 2012 runs as well as a detailed study of the experimental single-shot automated coupling correction and the comparison with the simulations. Wakefields problems experimented with the simultaneous measurement has been studied and will be solved by new target holders that will be installed in the next Fall 2012 run.

TUPB84

Storage Ring Tune Measurements using High-speed Metal-semiconductor-metal Photodetector

synchrotron, storage-ring, detector, electron

537

S. Dawson, D.J. Peake, R.P. Rassool
The University of Melbourne, Melbourne, Australia
M.J. Boland
ASCo, Clayton, Victoria, Australia
R.J. Steinhagen
CERN, Geneva, Switzerland

Knowledge of the betatron tunes within a storage ring is important to prevent the creation of instabilities and maximise the lifetime of the stored current within the ring. Typical tune measurements excite the beam and measure the resulting motion over time using electromagnetic pickups. The novel measurement technique presented utilises high-speed MSM photodiodes in a balanced detector set-up to measure the vertical and horizontal betatron tunes. Radiation from a bending magnet consists of both visible light and X-rays. The visible light is separated from the X-rays with an optical chicane and focussed onto a pair of length-matched optical fibers each coupled to an MSM photodiode. The specialised biasing circuit for the photodiodes is constructed in a balanced detector configuration to emphasise any motion in the beam. Signal resulting from beam motion is amplified and digitised for analysis. Using this set-up the tunes for the storage ring at the Australian Synchrotron have been measured and verified with comparison to existing tune measurement technologies. The results from the new optical tune measurement system will be presented and discussed.

WECC03

Intensity Imbalance Optical Interferometer Beam Size Monitor

diagnostics, synchrotron, storage-ring, damping

566

M.J. Boland
ASCo, Clayton, Victoria, Australia
T.M. Mitsuhashi, T. Naito
KEK, Ibaraki, Japan
K.P. Wootton
The University of Melbourne, Melbourne, Australia

The technique of measuring the beam size in a particle accelerator with an optical interferometer with the Mitsuhashi apparatus is well established and one of the only direct measurement techniques available. However, one of the limitations of the technique is the dynamic range and noise level of CCD cameras when measuring ultra low emittance beams and hence visibilities close to unity. A new design has been successfully tested to overcome these limitations by introducing a know intensity imbalance in one of the light paths of the interferometer. This modification reduces the visibility in a controlled way and lifts the measured interference pattern out of the noise level of the CCD, thus increasing the dynamic range of the apparatus. Results are presented from tests at the ATF2 at KEK and on the optical diagnostic beamline at the Australian Synchrotron storage ring.

Slides WECC03 [2.383 MB]

THTA01

Beam Position Monitors for Circular Accelerators

pick-up, impedance, resonance, closed-orbit

590

S. Hiramatsu
KEK, Ibaraki, Japan

The electrostatic induction type beam position monitors (BPMs) for circular accelerators such as proton synchrotrons and electron accumulation rings will be discussed. Discussions on the beam induced charge on the BPM pick-up electrodes, signal detection systems, and techniques of beam based alignment and beam based calibration will be given. For high beam current machines, the evaluation of the beam coupling impedance of BPM is an important issue to avoid the beam current limit by beam instabilities caused by BPM impedances. Another serious problem is the movement of BPMs by the thermal distortion of the beam pipe by high power synchrotron radiation. These problems will be also mentioned briefly.

Slides THTA01 [6.252 MB]