IBIC2014 - List of Keywords (feedback)

Paper	Title	Other Keywords	Page
MOCZB3	Comparison of Feedback Controller for Link Stabilizing Units of the Laser Based Synchronisation System used at the European XFEL	controls, laser, timing, electron	34
	M. Heuer, S. Pfeiffer, H. Schlarb DESY, Hamburg, Germany G. Lichtenberg HAW, Hamburg, Germany
	The European X-ray Free Electron Laser will allow scientists to perform experiments with an atomic scale resolution. To perform time resolved experiments at the end of the facility it is essential to provide a highly stable clock signal to all subsystems. The accuracy of this signal is extremely important since it defines limitations of precise measurement devices. A laser based synchronization system is used for the synchronization with an error in sub-femtosecond range. These light pulses are carried by an optical fiber and exposed to external disturbances which changes the optical length of the fiber. For that reason the up to 4 kilometer long fibers are actively stabilized using a controller implemented on the new MicroTCA Platform. Due to the high computation resources of this platform it is possible to attack the time delay of the link system with well known model based feedback control strategies. This contribution shows the design of a model based controller for such a system and compares the control performance of the previously used PID controller with advanced control algorithms at the currently installed laboratory setup.
	Slides MOCZB3 [4.973 MB]
Export •	reference for this paper to ※ LaTeX, ※ Text, ※ IS/RefMan, ※ EndNote (xml)

MOPF19	Design of a Profile Monitor with 12 Inches of Actuation for FRIB	alignment, diagnostics, interface, vacuum	97
	S. Rodriguez Esparza, G. Kiupel, I.N. Nesterenko FRIB, East Lansing, Michigan, USA
	Funding: FACILITY FOR RARE ISOTOPE BEAMS Actuated diagnostics present additional challenges that static diagnostics devices do not such as alignment, stability, and incorporating an appropriate drive mechanism. These challenges become even more apparent as the actuaded length increases. At the Facility for Rare Isotope Beams (FRIB) we plan on using a number of actuated diagnostics devices including a Profile Monitor (AKA: Wire Scanner) with 12 inches of actuation. The Profile Monitor uses tungsten wires to traverse the beam pipe aperture to measure the beam intensity with respect to it’s location in the X-Y plane. This paper will detail the design of the 12 inch Profile Monitor and how it is able to overcome the stability, alignment, and drive issues that come with the 12 inches of actuation.
	Poster MOPF19 [1.128 MB]
Export •	reference for this paper to ※ LaTeX, ※ Text, ※ IS/RefMan, ※ EndNote (xml)

TUPF18	Development of a Button BPM for the LCLS-II project	diagnostics, wakefield, electron, HOM	361
	A. Lunin, T.N. Khabiboulline, N. Solyak, V.P. Yakovlev Fermilab, Batavia, Illinois, USA
	A high sensitivity button BPM is under development for a linac section of the LCLS-II project. Since the LCLS-II linac will operate with bunch charge as low as 10 pC, we analyse various options for pickup button and feedthrough in order to maximize the BPM output signal at low charge regime. As a result the conceptual BPM design is proposed including an analytical estimation of the BPM performance as well as numerical simulation with CST Particle Studio and ANSYS HFSS. Both numerical methods show a good agreement of BPM output signals for various design parameters. Finally we describe the signal processing scheme and the electronics we are going to use.
	Poster TUPF18 [0.846 MB]
Export •	reference for this paper to ※ LaTeX, ※ Text, ※ IS/RefMan, ※ EndNote (xml)

WECYB3	Status of the Sirius RF BPM Electronics	electronics, hardware, FPGA, storage-ring	505
	S.R. Marques, R.A. Baron, G.B.M. Bruno, F.H. Cardoso, L.A. Martins, J.L.B. Neto, L.M. Russo, D.O. Tavares LNLS, Campinas, Brazil
	A modular and open-source RF BPM electronics based on the PICMG(R) MicroTCA.4 and ANSI/VITA 57.1 FMC standards has been developed to be used at Sirius, a 3 GeV low emittance synchrotron light source under construction in Brazil. This paper reports on the latest development advances focusing on bench tests of the second version of the RF front-end and evaluation of the electronics with beam at SPEAR3 (SSRL/SLAC). The interface of the BPM electronics with the orbit feedback system is also discussed.
	Slides WECYB3 [3.265 MB]
Export •	reference for this paper to ※ LaTeX, ※ Text, ※ IS/RefMan, ※ EndNote (xml)

WEPF04	A Cryogenic Current Comparator for the Low Energy Antiproton Facitities at CERN	pick-up, coupling, cryogenics, antiproton	530
	M.F. Fernandes, J. Tan CERN, Geneva, Switzerland C.P. Welsch Cockcroft Institute, Warrington, Cheshire, United Kingdom C.P. Welsch The University of Liverpool, Liverpool, United Kingdom
	Funding: Funded by the European Unions Seventh Framework Programme for research, technological development and demonstration under grant agreement no 289485. Several laboratories have shown the potential of using Superconducting QUantum Interference Device (SQUID) magnetometers together with superconductor magnetic shields to measure beam current intensities in the sub-micro-Ampere regime. CERN, in collaboration with GSI, Jena university and Helmholtz Institute Jena, is currently working on developing an improved version of such a current monitor for the Antiproton Decelerator (AD) and Extra Low ENergy Antiproton (ELENA) rings at CERN, aiming for better current resolution and overall system availability. This contribution will present the current design, including theoretical estimation of the current resolution; stability limits of SQUID systems and adaptation of the coupling circuit to the AD beam parameters; the analysis of thermal and mechanical cryostat modes.
Export •	reference for this paper to ※ LaTeX, ※ Text, ※ IS/RefMan, ※ EndNote (xml)

WEPF31	Sensor Studies for DC Current Transformer Application	ion, synchrotron, storage-ring, instrumentation	624
	E. Soliman, K. Hofmann TU Darmstadt, Darmstadt, Germany H. Reeg, M. Schwickert GSI, Darmstadt, Germany
	DC Current Transformers (DCCTs) are known since decades as non-intercepting standard tools for online beam current measurement in synchrotrons and storage rings. In general, the measurement principle of commonly used DCCTs is to introduce a modulating AC signal for a pair of ferromagnetic toroid. A passing DC ion beam leads to an asymmetric shift of the hysteresis curves of the toroid pair. However, a drawback for this measurement principle is found at certain revolution frequencies in ring accelerators, when interference caused by the modulating frequency and its harmonics leads to inaccurate readings by the DCCT. Recent developments of magnetic field sensors allow for new approaches towards a DCCT design without using the modulation principle. This paper shows a review of different kinds of usable magnetic sensors, their characteristics and how they could be used in novel DCCT instruments.
	Poster WEPF31 [4.396 MB]
Export •	reference for this paper to ※ LaTeX, ※ Text, ※ IS/RefMan, ※ EndNote (xml)

WEPD08	Beam Jitter Spectra Measurements of the APEX Photoinjector	laser, gun, timing, electron	652
	H.J. Qian, J.M. Byrd, L.R. Doolittle, Q. Du, D. Filippetto, G. Huang, F. Sannibale, R.P. Wells LBNL, Berkeley, California, USA J. Yang TUB, Beijing, People's Republic of China
	High repetition rate photoinjectors such as the APEX at LBNL are one of the enabling technologies for next generation MHz XFELs. Due to the higher repetition rate, a wider bandwidth is available for feedback systems to achieve ultra-stable beam performance. In a first step to improve APEX beam stability, the noise power spectra of the APEX laser beam and electron beam are characterized in terms of intensity and timing. Possible feedback systems are also discussed.
Export •	reference for this paper to ※ LaTeX, ※ Text, ※ IS/RefMan, ※ EndNote (xml)

WEPD23	Commissioning of the ALBA Fast Orbit Feedback System	kicker, injection, FPGA, controls	691
	A. Olmos, S. Blanch-Torné, G. Cuní, Z. Martí, J. Moldes, R. Petrocelli, S. Rubio-Manrique, X. Serra-Gallifa, D. Yépez ALBA-CELLS Synchrotron, Cerdanyola del Vallès, Spain
	The ALBA Fast Orbit FeedBack system (FOFB) started its commissioning phase in September 2013, when all the required hardware was installed and the development of different controls for the feedback started. This report shows our experience tuning the different parameters to setup the system, together with vibration and beam noise measurements at different conditions. Finally, the present results and future steps for this system are described.
	Poster WEPD23 [0.902 MB]
Export •	reference for this paper to ※ LaTeX, ※ Text, ※ IS/RefMan, ※ EndNote (xml)

WEPD24	New Features and Measurements using the Upgraded Transverse Multibunch Feedback at Diamond	damping, betatron, experiment, FPGA	696
	G. Rehm, M.G. Abbott, A.F.D. Morgan DLS, Oxfordshire, United Kingdom
	A Transverse Multi-Bunch Feedback has been used in the Diamond Storage Ring for the stabilization of instabilities since 2007. Following a recent upgrade of the FPGA code and EPICS layer, a set of new features is now available to support operation and machine development: Firstly, a bunch by bunch choice of feedback filter allows for better stabilization of a single high charge bunch in a hybrid fill pattern. Secondly, complex grow-damp experiments are now possible using a sequencer of internal states allowing precise measurements of the damping rates on a mode by mode basis. Thirdly, a phase locked loop excitation and detection has been implemented to allow both extremely fast (kHz update rates) and extremely precise tracking of the betatron tune frequencies. Finally, short FIR filters on the ADC input and DAC output enable a fine tuning of the impulse response to provide maximum bunch to bunch isolation, as for instance required for efficient bunch cleaning.
	Poster WEPD24 [1.977 MB]
Export •	reference for this paper to ※ LaTeX, ※ Text, ※ IS/RefMan, ※ EndNote (xml)

WEPD25	Upgrade Development Progress for the CERN SPS High Bandwidth Transverse Feedback Demonstrator System	kicker, controls, pick-up, timing	700
	J.E. Dusatko, J.M. Cesaratto, J.D. Fox, C.H. Rivetta SLAC, Menlo Park, California, USA S. De Santis LBNL, Berkeley, California, USA W. Höfle CERN, Geneva, Switzerland
	Funding: Work supported by the U.S. Department of Energy under contract DE-AC02-76SF00515 and the US LHC Accelerator Research Program (LARP) A high bandwidth feedback demonstrator system has been developed for proof of concept transverse intra-bunch closed loop feedback control studies at the CERN SPS. This system contains a beam pickup, analog front end receiver, signal processor, back end driver, power amplifiers and kicker structure. The main signal processing functions are performed digitally, using very fast (4GSa/s) data converters to bring the system signals into and out of the digital domain. The digital signal processing function is flexibly implemented in an FPGA allowing for maximum speed and reconfigurability for testing multiple control algorithms. The signal processor is a modular design consisting of commercial and custom components. This approach allowed for a rapidly-developed prototype to be delivered in a short time with limited resources. Initial beam studies at the SPS using the system prior to the CERN long shutdown one (LS1) have been very encouraging. We are planning several key upgrades to the system, including the signal processor. This paper describes these upgrades and reports on their progress.
	Poster WEPD25 [1.301 MB]
Export •	reference for this paper to ※ LaTeX, ※ Text, ※ IS/RefMan, ※ EndNote (xml)

WEPD26	Bunch-by-Bunch Feedback Systems at the DELTA Storage Ring used for Beam Diagnostics	damping, storage-ring, laser, radiation	703
	M. Höner, S. Khan, M. Sommer DELTA, Dortmund, Germany
	Funding: Work supported by the BMBF. At the 1.5-GeV electron storage ring DELTA operated by the TU Dortmund University, a bunch-by-bunch feedback system was installed in 2011. Since then, it is in operation for different beam diagnostic purposes. A fast analysis of bunch-position data allows a real-time multibunch mode analysis during machine operation. In addition, the data analysis can be triggered by external events, e.g. beam losses or the injection process. In this paper, a feedback-based method to measure the damping times of multi-bunch modes is presented. Furthermore, a chromaticity-dependent single-bunch instability is analyzed. Finally, the use of the feedback system in the presence of an RF-phase modulation is presented.
Export •	reference for this paper to ※ LaTeX, ※ Text, ※ IS/RefMan, ※ EndNote (xml)

WEPD27	Commissioning of Bunch-by-Bunch Feedback System for NSLS2 Storage Ring	ion, storage-ring, kicker, betatron	707
	W.X. Cheng, B. Bacha, Y. Hu, O. Singh, H. Xu BNL, Upton, Long Island, New York, USA D. Teytelman Dimtel, San Jose, USA
	NSLS2 Storage Ring transverse bunch by bunch feedback system has been designed to cure the coupled bunch instabilities, caused by HOM, resistive wall or ions. The system has been constructed, tested and commissioned with beam. Preliminary studies show that the feedback system can suppress single bunch instability. Mode analysis of the unstable coupled bunch motion reveals fast ion instability exist even at relative low current. The bunch by bunch feedback system performance will be presented in this paper.
	Poster WEPD27 [0.623 MB]
Export •	reference for this paper to ※ LaTeX, ※ Text, ※ IS/RefMan, ※ EndNote (xml)

THCXB2	Performance Evaluation of the Intra-Bunch Feedback System at J-PARC Main Ring	simulation, damping, betatron, experiment	727
	K.G. Nakamura Kyoto University, Kyoto, Japan Y.H. Chin, T. Koseki, H. Kuboki, M. Okada, M. Tobiyama KEK, Ibaraki, Japan Y. Shobuda JAEA/J-PARC, Tokai-Mura, Naka-Gun, Ibaraki-Ken, Japan T. Toyama J-PARC, KEK & JAEA, Ibaraki-ken, Japan
	Intra-bunch feedback system in J-PARC (Japan Proton Accelerator Complex) Main Ring(MR) has been developed for suppression of head-tail motion and reduction of beam loss. This system consists of mainly BPM, signal processing circuit (iGp12), power amplifiers, and stripline kickers. These components were fabricated and installed in April of 2014. This system succeeded in suppressing the internal bunch motion caused by injection kicker error in the 3GeV constant-energy operation, and showed shorter damping time compared to the bunch by bunch feedback system, which is currently working in the normal operation. In this paper, we will report the performance of the system by comparison with simulations.
	Slides THCXB2 [6.430 MB]
Export •	reference for this paper to ※ LaTeX, ※ Text, ※ IS/RefMan, ※ EndNote (xml)

Paper

Title

Other Keywords

Page

Comparison of Feedback Controller for Link Stabilizing Units of the Laser Based Synchronisation System used at the European XFEL

controls, laser, timing, electron

34

M. Heuer, S. Pfeiffer, H. Schlarb
DESY, Hamburg, Germany
G. Lichtenberg
HAW, Hamburg, Germany

The European X-ray Free Electron Laser will allow scientists to perform experiments with an atomic scale resolution. To perform time resolved experiments at the end of the facility it is essential to provide a highly stable clock signal to all subsystems. The accuracy of this signal is extremely important since it defines limitations of precise measurement devices. A laser based synchronization system is used for the synchronization with an error in sub-femtosecond range. These light pulses are carried by an optical fiber and exposed to external disturbances which changes the optical length of the fiber. For that reason the up to 4 kilometer long fibers are actively stabilized using a controller implemented on the new MicroTCA Platform. Due to the high computation resources of this platform it is possible to attack the time delay of the link system with well known model based feedback control strategies. This contribution shows the design of a model based controller for such a system and compares the control performance of the previously used PID controller with advanced control algorithms at the currently installed laboratory setup.

Slides MOCZB3 [4.973 MB]

Export •

reference for this paper to ※ LaTeX, ※ Text, ※ IS/RefMan, ※ EndNote (xml)

MOPF19

Design of a Profile Monitor with 12 Inches of Actuation for FRIB

alignment, diagnostics, interface, vacuum

97

S. Rodriguez Esparza, G. Kiupel, I.N. Nesterenko
FRIB, East Lansing, Michigan, USA

Funding: FACILITY FOR RARE ISOTOPE BEAMS
Actuated diagnostics present additional challenges that static diagnostics devices do not such as alignment, stability, and incorporating an appropriate drive mechanism. These challenges become even more apparent as the actuaded length increases. At the Facility for Rare Isotope Beams (FRIB) we plan on using a number of actuated diagnostics devices including a Profile Monitor (AKA: Wire Scanner) with 12 inches of actuation. The Profile Monitor uses tungsten wires to traverse the beam pipe aperture to measure the beam intensity with respect to it’s location in the X-Y plane. This paper will detail the design of the 12 inch Profile Monitor and how it is able to overcome the stability, alignment, and drive issues that come with the 12 inches of actuation.

Poster MOPF19 [1.128 MB]

Export •

reference for this paper to ※ LaTeX, ※ Text, ※ IS/RefMan, ※ EndNote (xml)

TUPF18

Development of a Button BPM for the LCLS-II project

diagnostics, wakefield, electron, HOM

361

A. Lunin, T.N. Khabiboulline, N. Solyak, V.P. Yakovlev
Fermilab, Batavia, Illinois, USA

A high sensitivity button BPM is under development for a linac section of the LCLS-II project. Since the LCLS-II linac will operate with bunch charge as low as 10 pC, we analyse various options for pickup button and feedthrough in order to maximize the BPM output signal at low charge regime. As a result the conceptual BPM design is proposed including an analytical estimation of the BPM performance as well as numerical simulation with CST Particle Studio and ANSYS HFSS. Both numerical methods show a good agreement of BPM output signals for various design parameters. Finally we describe the signal processing scheme and the electronics we are going to use.

Poster TUPF18 [0.846 MB]

Export •

reference for this paper to ※ LaTeX, ※ Text, ※ IS/RefMan, ※ EndNote (xml)

WECYB3

Status of the Sirius RF BPM Electronics

electronics, hardware, FPGA, storage-ring

505

S.R. Marques, R.A. Baron, G.B.M. Bruno, F.H. Cardoso, L.A. Martins, J.L.B. Neto, L.M. Russo, D.O. Tavares
LNLS, Campinas, Brazil

A modular and open-source RF BPM electronics based on the PICMG(R) MicroTCA.4 and ANSI/VITA 57.1 FMC standards has been developed to be used at Sirius, a 3 GeV low emittance synchrotron light source under construction in Brazil. This paper reports on the latest development advances focusing on bench tests of the second version of the RF front-end and evaluation of the electronics with beam at SPEAR3 (SSRL/SLAC). The interface of the BPM electronics with the orbit feedback system is also discussed.

Slides WECYB3 [3.265 MB]

Export •

reference for this paper to ※ LaTeX, ※ Text, ※ IS/RefMan, ※ EndNote (xml)

WEPF04

A Cryogenic Current Comparator for the Low Energy Antiproton Facitities at CERN

pick-up, coupling, cryogenics, antiproton

530

M.F. Fernandes, J. Tan
CERN, Geneva, Switzerland
C.P. Welsch
Cockcroft Institute, Warrington, Cheshire, United Kingdom
C.P. Welsch
The University of Liverpool, Liverpool, United Kingdom

Funding: Funded by the European Unions Seventh Framework Programme for research, technological development and demonstration under grant agreement no 289485.
Several laboratories have shown the potential of using Superconducting QUantum Interference Device (SQUID) magnetometers together with superconductor magnetic shields to measure beam current intensities in the sub-micro-Ampere regime. CERN, in collaboration with GSI, Jena university and Helmholtz Institute Jena, is currently working on developing an improved version of such a current monitor for the Antiproton Decelerator (AD) and Extra Low ENergy Antiproton (ELENA) rings at CERN, aiming for better current resolution and overall system availability. This contribution will present the current design, including theoretical estimation of the current resolution; stability limits of SQUID systems and adaptation of the coupling circuit to the AD beam parameters; the analysis of thermal and mechanical cryostat modes.

Export •

reference for this paper to ※ LaTeX, ※ Text, ※ IS/RefMan, ※ EndNote (xml)

WEPF31

Sensor Studies for DC Current Transformer Application

ion, synchrotron, storage-ring, instrumentation

624

E. Soliman, K. Hofmann
TU Darmstadt, Darmstadt, Germany
H. Reeg, M. Schwickert
GSI, Darmstadt, Germany

DC Current Transformers (DCCTs) are known since decades as non-intercepting standard tools for online beam current measurement in synchrotrons and storage rings. In general, the measurement principle of commonly used DCCTs is to introduce a modulating AC signal for a pair of ferromagnetic toroid. A passing DC ion beam leads to an asymmetric shift of the hysteresis curves of the toroid pair. However, a drawback for this measurement principle is found at certain revolution frequencies in ring accelerators, when interference caused by the modulating frequency and its harmonics leads to inaccurate readings by the DCCT. Recent developments of magnetic field sensors allow for new approaches towards a DCCT design without using the modulation principle. This paper shows a review of different kinds of usable magnetic sensors, their characteristics and how they could be used in novel DCCT instruments.

Poster WEPF31 [4.396 MB]

Export •

reference for this paper to ※ LaTeX, ※ Text, ※ IS/RefMan, ※ EndNote (xml)

WEPD08

Beam Jitter Spectra Measurements of the APEX Photoinjector

laser, gun, timing, electron

652

H.J. Qian, J.M. Byrd, L.R. Doolittle, Q. Du, D. Filippetto, G. Huang, F. Sannibale, R.P. Wells
LBNL, Berkeley, California, USA
J. Yang
TUB, Beijing, People's Republic of China

High repetition rate photoinjectors such as the APEX at LBNL are one of the enabling technologies for next generation MHz XFELs. Due to the higher repetition rate, a wider bandwidth is available for feedback systems to achieve ultra-stable beam performance. In a first step to improve APEX beam stability, the noise power spectra of the APEX laser beam and electron beam are characterized in terms of intensity and timing. Possible feedback systems are also discussed.

Export •

reference for this paper to ※ LaTeX, ※ Text, ※ IS/RefMan, ※ EndNote (xml)

WEPD23

Commissioning of the ALBA Fast Orbit Feedback System

kicker, injection, FPGA, controls

691

A. Olmos, S. Blanch-Torné, G. Cuní, Z. Martí, J. Moldes, R. Petrocelli, S. Rubio-Manrique, X. Serra-Gallifa, D. Yépez
ALBA-CELLS Synchrotron, Cerdanyola del Vallès, Spain

The ALBA Fast Orbit FeedBack system (FOFB) started its commissioning phase in September 2013, when all the required hardware was installed and the development of different controls for the feedback started. This report shows our experience tuning the different parameters to setup the system, together with vibration and beam noise measurements at different conditions. Finally, the present results and future steps for this system are described.

Poster WEPD23 [0.902 MB]

Export •

reference for this paper to ※ LaTeX, ※ Text, ※ IS/RefMan, ※ EndNote (xml)

WEPD24

New Features and Measurements using the Upgraded Transverse Multibunch Feedback at Diamond

damping, betatron, experiment, FPGA

696

G. Rehm, M.G. Abbott, A.F.D. Morgan
DLS, Oxfordshire, United Kingdom

A Transverse Multi-Bunch Feedback has been used in the Diamond Storage Ring for the stabilization of instabilities since 2007. Following a recent upgrade of the FPGA code and EPICS layer, a set of new features is now available to support operation and machine development: Firstly, a bunch by bunch choice of feedback filter allows for better stabilization of a single high charge bunch in a hybrid fill pattern. Secondly, complex grow-damp experiments are now possible using a sequencer of internal states allowing precise measurements of the damping rates on a mode by mode basis. Thirdly, a phase locked loop excitation and detection has been implemented to allow both extremely fast (kHz update rates) and extremely precise tracking of the betatron tune frequencies. Finally, short FIR filters on the ADC input and DAC output enable a fine tuning of the impulse response to provide maximum bunch to bunch isolation, as for instance required for efficient bunch cleaning.

Poster WEPD24 [1.977 MB]

Export •

reference for this paper to ※ LaTeX, ※ Text, ※ IS/RefMan, ※ EndNote (xml)

WEPD25

Upgrade Development Progress for the CERN SPS High Bandwidth Transverse Feedback Demonstrator System

kicker, controls, pick-up, timing

700

J.E. Dusatko, J.M. Cesaratto, J.D. Fox, C.H. Rivetta
SLAC, Menlo Park, California, USA
S. De Santis
LBNL, Berkeley, California, USA
W. Höfle
CERN, Geneva, Switzerland

Funding: Work supported by the U.S. Department of Energy under contract DE-AC02-76SF00515 and the US LHC Accelerator Research Program (LARP)
A high bandwidth feedback demonstrator system has been developed for proof of concept transverse intra-bunch closed loop feedback control studies at the CERN SPS. This system contains a beam pickup, analog front end receiver, signal processor, back end driver, power amplifiers and kicker structure. The main signal processing functions are performed digitally, using very fast (4GSa/s) data converters to bring the system signals into and out of the digital domain. The digital signal processing function is flexibly implemented in an FPGA allowing for maximum speed and reconfigurability for testing multiple control algorithms. The signal processor is a modular design consisting of commercial and custom components. This approach allowed for a rapidly-developed prototype to be delivered in a short time with limited resources. Initial beam studies at the SPS using the system prior to the CERN long shutdown one (LS1) have been very encouraging. We are planning several key upgrades to the system, including the signal processor. This paper describes these upgrades and reports on their progress.

Poster WEPD25 [1.301 MB]

Export •

reference for this paper to ※ LaTeX, ※ Text, ※ IS/RefMan, ※ EndNote (xml)

WEPD26

Bunch-by-Bunch Feedback Systems at the DELTA Storage Ring used for Beam Diagnostics

damping, storage-ring, laser, radiation

703

M. Höner, S. Khan, M. Sommer
DELTA, Dortmund, Germany

Funding: Work supported by the BMBF.
At the 1.5-GeV electron storage ring DELTA operated by the TU Dortmund University, a bunch-by-bunch feedback system was installed in 2011. Since then, it is in operation for different beam diagnostic purposes. A fast analysis of bunch-position data allows a real-time multibunch mode analysis during machine operation. In addition, the data analysis can be triggered by external events, e.g. beam losses or the injection process. In this paper, a feedback-based method to measure the damping times of multi-bunch modes is presented. Furthermore, a chromaticity-dependent single-bunch instability is analyzed. Finally, the use of the feedback system in the presence of an RF-phase modulation is presented.

Export •

reference for this paper to ※ LaTeX, ※ Text, ※ IS/RefMan, ※ EndNote (xml)

WEPD27

Commissioning of Bunch-by-Bunch Feedback System for NSLS2 Storage Ring

ion, storage-ring, kicker, betatron

707

W.X. Cheng, B. Bacha, Y. Hu, O. Singh, H. Xu
BNL, Upton, Long Island, New York, USA
D. Teytelman
Dimtel, San Jose, USA

NSLS2 Storage Ring transverse bunch by bunch feedback system has been designed to cure the coupled bunch instabilities, caused by HOM, resistive wall or ions. The system has been constructed, tested and commissioned with beam. Preliminary studies show that the feedback system can suppress single bunch instability. Mode analysis of the unstable coupled bunch motion reveals fast ion instability exist even at relative low current. The bunch by bunch feedback system performance will be presented in this paper.

Poster WEPD27 [0.623 MB]

Export •

reference for this paper to ※ LaTeX, ※ Text, ※ IS/RefMan, ※ EndNote (xml)

THCXB2

Performance Evaluation of the Intra-Bunch Feedback System at J-PARC Main Ring

simulation, damping, betatron, experiment

727

K.G. Nakamura
Kyoto University, Kyoto, Japan
Y.H. Chin, T. Koseki, H. Kuboki, M. Okada, M. Tobiyama
KEK, Ibaraki, Japan
Y. Shobuda
JAEA/J-PARC, Tokai-Mura, Naka-Gun, Ibaraki-Ken, Japan
T. Toyama
J-PARC, KEK & JAEA, Ibaraki-ken, Japan

Intra-bunch feedback system in J-PARC (Japan Proton Accelerator Complex) Main Ring(MR) has been developed for suppression of head-tail motion and reduction of beam loss. This system consists of mainly BPM, signal processing circuit (iGp12), power amplifiers, and stripline kickers. These components were fabricated and installed in April of 2014. This system succeeded in suppressing the internal bunch motion caused by injection kicker error in the 3GeV constant-energy operation, and showed shorter damping time compared to the bunch by bunch feedback system, which is currently working in the normal operation. In this paper, we will report the performance of the system by comparison with simulations.

Slides THCXB2 [6.430 MB]

Export •

reference for this paper to ※ LaTeX, ※ Text, ※ IS/RefMan, ※ EndNote (xml)