IBIC2012 - List of Keywords (electronics)

Paper	Title	Other Keywords	Page
MOCB02	A Generic BPM Electronics Platform for European XFEL, SwissFEL and SLS	FPGA, cavity, interface, FEL	11
	B. Keil, R. Baldinger, R. Ditter, W. Koprek, R. Kramert, G. Marinkovic, M. Roggli, M. Stadler, D.M. Treyer PSI, Villigen PSI, Switzerland
	Funding: Work supported by Swiss State Secretariat for Education and Research SER PSI is currently developing the 2nd generation of a generic modular electronics platform for linac and storage ring BPMs and other beam diagnostics systems. The first platform, developed in 2004 and based on a generic digital back-end with Xilinx Virtex 2Pro FPGAs, is currently used at PSI for proton accelerator BPMs, resonant stripline BPMs at the SwissFEL test injector facility, and a number of other diagnostics and detector systems. The 2nd platform will be employed e.g. for European XFEL BPMs, a new SLS BPM system, and the SwissFEL BPM system. This paper gives an overview of the architecture, features and applications of the new platform, including interfaces to control, timing and feedback systems. Differences and synergies of the different BPM and non-BPM applications will be discussed.
	Slides MOCB02 [2.440 MB]

MOPA15	New Electronics Design for the European XFEL Re-entrant Cavity Monitor	cavity, FPGA, dipole, linac	83
	C.S. Simon CEA/DSM/IRFU, France N. Baboi DESY, Hamburg, Germany R. Baldinger, B. Keil, R. Kramert, G. Marinkovic, M. Roggli, M. Stadler PSI, Villigen PSI, Switzerland
	About one third of the beam position monitors (BPMs) in the European XFEL (E-XFEL) cryomodules will be re-entrant cavities. The BPM mechanics and Radio-Frequency front-end (RFFE) electronics are developed by CEA/Saclay. Two RFFEs and a digital back-end with two ADC mezzanines are integrated into a compact standalone unit called MBU (modular BPM unit) developed by PSI. The signal processing uses hybrids and a single stage downconversion to generate the signals sum and delta. Every RF/analog component of the re-entrant BPM electronics has been simulated with a Mathcad model and tested independently on test benches. The very low Q of the cavity monopole mode allows the new electronics to filter this mode at the dipole mode frequency and an IQ demodulation for delta and sum channels allow the digital back-end to determine the sign of the beam position just by comparing the phases of the channels, independently of beam arrival time jitter and external reference clock phase. This paper describes the design and architecture of a new re-entrant BPM electronics, including results of beam tests at FLASH that were performed to validate the chosen design.

MOPA16	Design and Characterization of a Prototype Stripline Beam Position Monitor for the CLIC Drive Beam	simulation, pick-up, damping, impedance	87
	A. Benot-Morell, L. Søby, M. Wendt CERN, Geneva, Switzerland A. Benot-Morell IFIC, Valencia, Spain J.M. Nappa, J. Tassan-Viol, S. Vilalte IN2P3-LAPP, Annecy-le-Vieux, France S.R. Smith SLAC, Menlo Park, California, USA
	Funding: FPA2010-21456-C02-01, SEIC-2010-00028 The prototype of a stripline Beam Position Monitor (BPM) with its associated readout electronics is under development at CERN, in collaboration with SLAC, LAPP and IFIC. The anticipated position resolution and accuracy are expected to be below 2μm and 20μm respectively for operation of the BPM in the CLIC drive beam (DB) linac. This paper describes the particular CLIC DB conditions with respect to the beam position monitoring, presents the measurement concept, and summarizes electromagnetic simulations and RF measurements performed on the prototype.

MOPA18	A Prototype Cavity Beam Position Monitor for the CLIC Main Beam	cavity, dipole, coupling, 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, coupling, controls, impedance	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.

MOPA47	Planar Transmission Line BPM for Horizontal Aperture Chicane for XFEL	pick-up, simulation, electron, kicker	168
	A. Angelovski, R. Jakoby, A. Penirschke TU Darmstadt, Darmstadt, Germany C. Gerth, U. Mavrič, C. Sydlo DESY, Hamburg, Germany
	In order to obtain ultra-short bunches in the Free Electron Laser FLASH at DESY, the electron beam is compressed in magnetic chicanes. Precise knowledge of the beam position in the chicane is of great significance for the longitudinal dynamics control. In the current implementation cylindrical pickup-striplines mounted perpendicularly to the beam are used as a Beam Position Monitor (BPM)(). One can determine the horizontal beam position by measuring the phase difference of the beam induced signal at opposite ends of a pickup. Due to the different electrical and mechanical requirements for the European XFEL a new BPM has to be developed. In this paper, we present the design and analysis of a planar transmission line structure which is planned to be used as a BPM in the European XFEL. The planar design of the pickups can provide for proper impedance match to the subsequent electronics as well as sufficient mechanical stability along the aperture when using alumina substrates. A scaled non-hermetic prototype of the BPM is built and characterized by scattering parameters. The measurement results are compared to simulations obtained by CST STUDIO SUITE®. () K. Hacker at el, Proceedings of DIPAC 2007, Venice, Italy 2007, p.108

MOPB87	Development and First Tests of a High Sensitivity Charge Monitor for SwissFEL	electron, operation, FEL, instrumentation	287
	S. Artinian, J.F. Bergoz, F. Stulle BERGOZ Instrumentation, Saint Genis Pouilly, France P. Pollet, V. Schlott PSI, Villigen PSI, Switzerland
	The compact X-ray free electron laser SwissFEL, which is presently under development at the Paul Scherrer Institut (PSI) in Villigen, Switzerland, will operate at comparably low charges, allowing the compression of the electron bunches to a few femto-seconds (nominal 200 pC mode) and even towards the atto-second range (short bunch 10 pC mode). A high precision charge measurement turns out to be a challenge, especially in the presence of dark currents, which may occur from high gradient RF gun and accelerating structure operation. In response to this challenge, a higher sensitivity charge transformer and new beam charge monitor electronics were developed in collaboration between Bergoz Instrumentation and PSI. The Turbo-ICT captures sub-pC bunch charge thanks to a new magnetic alloy exhibiting very low core loss. Transmission over a carrier using narrow-band cable television technique preserves the signal integrity from the Turbo-ICT to the BCM-RF. Electro-magnetic and RF interferences are strongly attenuated; the dark current signal is suppressed. First beam test results, which have been performed at the SwissFEL Test Injector Facility (STIF), are presented in this contribution.

TUPA15	Beam Postion Monitor for Energy Recovery Linac	pick-up, linac, vacuum, monitoring	361
	I. Pinayev BNL, Upton, Long Island, New York, USA
	Funding: This work is supported by US Department of Energy. The energy recovery linacs have co-propagating beams in the same vacuum vessel. These beams can have different trajectories, which should be distinguished by beam position monitors (BPM). In this paper we present a concept of BPM utilizing the phase information for calculation individual position of each of the two beams (accelerating and decelerating). The practical realizations are presented and achievable accuracy is estimated.

TUPA16	HOM Choice Study with Test Electronics for use as Beam Position Diagnostics in 3.9 GHz Accelerating Cavities in FLASH	cavity, HOM, dipole, electron	364
	N. Baboi, B. Lorbeer, P. Zhang DESY, Hamburg, Germany N. Eddy, B.J. Fellenz, M. Wendt Fermilab, Batavia, USA
	Funding: Work supported in part by the European Commission within the Framework Programme 7, Grant Agreement 227579 Higher Order Modes (HOM) excited by the beam in the 3.9 GHz accelerating cavities in FLASH can be used for beam position diagnostics, as in a cavity beam position monitor. Previous studies of the modal choices within the complicated spectrum have revealed several options: cavity modes with high coupling to the beam, and therefore with the potential for better position resolution, but which are propagating within all 4 cavities, and modes localized in the cavities or the beam pipes, which can give localized position information, but which provide worse resolution. For a better characterization of these options, test electronics has been built, which can down convert various frequencies between about 4 and 9 GHz to 70 MHz. The performance of various 20 MHz bands has been estimated. The best resolution of 20 μm was found for some propagating modes. Based on this study one band at ca. 5 GHz was chosen for high resolution position monitoring and a band at ca. 9 GHz for localized monitoring. N. Baboi et al., SRF2011, Chicago, IL, US

TUPA17	TPS BPM Electronics Performance Measurement and Statistics	FPGA, EPICS, booster, controls	369
	P.C. Chiu, K.T. Hsu, K.H. Hu, C.H. Kuo NSRRC, Hsinchu, Taiwan
	The new BPM electronics Libera Brilliance Plus are developed for Taiwan Photon Source (TPS) which is a 3 GeV synchrotron light source constructed at NSRRC. This new BPM electronics can accommodate four BPM modules with integrated FPGA-based hardware. The preliminary test for the first arrival unit had been performed in the TLS (Taiwan Light Source) and had shown nearly equal performance compared with Libera Brilliance. The extra 75 sets had been delivered in 2011 and 2012. Performance of each unit are individually tested and measured.

TUPA19	First Tests of a Low Charge MTCA-based Electronics for Button and Strip-line BPM at FLASH	detector, timing, electron, operation	378
	B. Lorbeer, N. Baboi, F. Schmidt-Föhre DESY, Hamburg, Germany
	Current FEL based light sources foresee operation with very short electron bunches. These can be obtained with charges of 100pC and lower. The specified charge range for FLASH, DESY, Hamburg goes from 100pC up to 1nC. The electronics currently installed at button and stripline BPMs of FLASH have been designed for best performance at higher charges and have reached their limits. Currently a new type of electronics is being developed at DESY to overcome these limitations. These electronics is/are conforming with the uTCA for physics standard(ref). This paper describes the next generation of FLASH BPM electronics suitable for button and stripline BPM. Furthermore the first measurement results taken with beam at FLASH, DESY are presented here.

TUPA23	Performance of a Downconverter Test-electronics with MTCA-based Digitizers for Beam Position Monitoring in 3.9 GHz Accelerating Cavities	HOM, electron, cavity, monitoring	386
	T. Wamsat, N. Baboi, B. Lorbeer DESY, Hamburg, Germany P. Zhang UMAN, Manchester, United Kingdom
	Beam excited higher order modes (HOM) in 3.9GHz accelerating cavities at the European XFEL are planned to be used for beam position monitoring. The selected HOMs are located around 5440MHz and 9060MHz and are filtered in a bandwidth of 100MHz. A downconverter test electronics converts the HOMs to an intermediate frequency of 70MHz. The μTCA (Micro Telecommunications Computing Architecture) standard will be used for the XFEL. Thus it is important to have a performance study of the downconverter test electronics using the μTCA digitizer card SIS8300. In the digitizer IF frequency of 70MHz is undersampled with a clock frequency of 108MS/s. The paper will present the performance of the digitizer together with the test-electronics. A comparison with a 216MS/s VME (Versa Module Eurocard) digitizer will be made.

TUPA25	Signal Transmission Characteristics in Stripline-Type Beam Position Monitor	coupling, impedance, 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.

TUPA26	Development of New BPM Electronics for the Swiss Light Source	FPGA, controls, feedback, hardware	399
	W. Koprek, R. Baldinger, R. Ditter, B. Keil, G. Marinkovic, M. Roggli, M. Stadler PSI, Villigen PSI, Switzerland
	PSI is currently developing new BPM electronics for the Swiss Light Source (SLS). Although the present "DBPM1" system that was designed 12 years ago still allows to achieve excellent beam stability and uptime, the development of a new system is motivated by long-term maintenance, improved performance in line with increasing user requirements, and new features and functionality provided by latest electronics technology. The new electronics is based on a generic modular BPM electronics platform developed by PSI that will also be used for linac based FELs like European XFEL and SwissFEL. The hardware and firmware architecture of the present prototypes as well as first test results will be presented.

TUPA27	Beam Test Results of Undulator Cavity BPM Electronics for the European XFEL	cavity, pick-up, undulator, feedback	404
	M. Stadler, R. Baldinger, R. Ditter, B. Keil, R. Kramert, G. Marinkovic, M. Roggli PSI, Villigen PSI, Switzerland D. Lipka, D. Nölle, M. Pelzer, S. Vilcins DESY, Hamburg, Germany
	Funding: Work supported by Swiss State Secretariat for Education and Research SER The European X-ray Free Electron Laser (E-XFEL) will use dual-resonator cavity BPMs (CBPMs) in the SASE undulators to measure and stabilize the beam trajectory. The BPM electronics is developed by PSI, while the pickup mechanics is developed by DESY. First beam tests with three adjacent pickups have been performed. The system architecture and algorithms, achieved performance and noise correlation measurements of the present electronics prototypes will be presented.

Paper

Title

Other Keywords

Page

MOCB02

A Generic BPM Electronics Platform for European XFEL, SwissFEL and SLS

FPGA, cavity, interface, FEL

11

B. Keil, R. Baldinger, R. Ditter, W. Koprek, R. Kramert, G. Marinkovic, M. Roggli, M. Stadler, D.M. Treyer
PSI, Villigen PSI, Switzerland

Funding: Work supported by Swiss State Secretariat for Education and Research SER
PSI is currently developing the 2nd generation of a generic modular electronics platform for linac and storage ring BPMs and other beam diagnostics systems. The first platform, developed in 2004 and based on a generic digital back-end with Xilinx Virtex 2Pro FPGAs, is currently used at PSI for proton accelerator BPMs, resonant stripline BPMs at the SwissFEL test injector facility, and a number of other diagnostics and detector systems. The 2nd platform will be employed e.g. for European XFEL BPMs, a new SLS BPM system, and the SwissFEL BPM system. This paper gives an overview of the architecture, features and applications of the new platform, including interfaces to control, timing and feedback systems. Differences and synergies of the different BPM and non-BPM applications will be discussed.

Slides MOCB02 [2.440 MB]

MOPA15

New Electronics Design for the European XFEL Re-entrant Cavity Monitor

cavity, FPGA, dipole, linac

83

C.S. Simon
CEA/DSM/IRFU, France
N. Baboi
DESY, Hamburg, Germany
R. Baldinger, B. Keil, R. Kramert, G. Marinkovic, M. Roggli, M. Stadler
PSI, Villigen PSI, Switzerland

About one third of the beam position monitors (BPMs) in the European XFEL (E-XFEL) cryomodules will be re-entrant cavities. The BPM mechanics and Radio-Frequency front-end (RFFE) electronics are developed by CEA/Saclay. Two RFFEs and a digital back-end with two ADC mezzanines are integrated into a compact standalone unit called MBU (modular BPM unit) developed by PSI. The signal processing uses hybrids and a single stage downconversion to generate the signals sum and delta. Every RF/analog component of the re-entrant BPM electronics has been simulated with a Mathcad model and tested independently on test benches. The very low Q of the cavity monopole mode allows the new electronics to filter this mode at the dipole mode frequency and an IQ demodulation for delta and sum channels allow the digital back-end to determine the sign of the beam position just by comparing the phases of the channels, independently of beam arrival time jitter and external reference clock phase. This paper describes the design and architecture of a new re-entrant BPM electronics, including results of beam tests at FLASH that were performed to validate the chosen design.

MOPA16

Design and Characterization of a Prototype Stripline Beam Position Monitor for the CLIC Drive Beam

simulation, pick-up, damping, impedance

87

A. Benot-Morell, L. Søby, M. Wendt
CERN, Geneva, Switzerland
A. Benot-Morell
IFIC, Valencia, Spain
J.M. Nappa, J. Tassan-Viol, S. Vilalte
IN2P3-LAPP, Annecy-le-Vieux, France
S.R. Smith
SLAC, Menlo Park, California, USA

Funding: FPA2010-21456-C02-01, SEIC-2010-00028
The prototype of a stripline Beam Position Monitor (BPM) with its associated readout electronics is under development at CERN, in collaboration with SLAC, LAPP and IFIC. The anticipated position resolution and accuracy are expected to be below 2μm and 20μm respectively for operation of the BPM in the CLIC drive beam (DB) linac. This paper describes the particular CLIC DB conditions with respect to the beam position monitoring, presents the measurement concept, and summarizes electromagnetic simulations and RF measurements performed on the prototype.

MOPA18

A Prototype Cavity Beam Position Monitor for the CLIC Main Beam

cavity, dipole, coupling, 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, coupling, controls, impedance

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.

MOPA47

Planar Transmission Line BPM for Horizontal Aperture Chicane for XFEL

pick-up, simulation, electron, kicker

168

A. Angelovski, R. Jakoby, A. Penirschke
TU Darmstadt, Darmstadt, Germany
C. Gerth, U. Mavrič, C. Sydlo
DESY, Hamburg, Germany

In order to obtain ultra-short bunches in the Free Electron Laser FLASH at DESY, the electron beam is compressed in magnetic chicanes. Precise knowledge of the beam position in the chicane is of great significance for the longitudinal dynamics control. In the current implementation cylindrical pickup-striplines mounted perpendicularly to the beam are used as a Beam Position Monitor (BPM)(*). One can determine the horizontal beam position by measuring the phase difference of the beam induced signal at opposite ends of a pickup. Due to the different electrical and mechanical requirements for the European XFEL a new BPM has to be developed. In this paper, we present the design and analysis of a planar transmission line structure which is planned to be used as a BPM in the European XFEL. The planar design of the pickups can provide for proper impedance match to the subsequent electronics as well as sufficient mechanical stability along the aperture when using alumina substrates. A scaled non-hermetic prototype of the BPM is built and characterized by scattering parameters. The measurement results are compared to simulations obtained by CST STUDIO SUITE®.
(*) K. Hacker at el, Proceedings of DIPAC 2007, Venice, Italy 2007, p.108

MOPB87

Development and First Tests of a High Sensitivity Charge Monitor for SwissFEL

electron, operation, FEL, instrumentation

287

S. Artinian, J.F. Bergoz, F. Stulle
BERGOZ Instrumentation, Saint Genis Pouilly, France
P. Pollet, V. Schlott
PSI, Villigen PSI, Switzerland

The compact X-ray free electron laser SwissFEL, which is presently under development at the Paul Scherrer Institut (PSI) in Villigen, Switzerland, will operate at comparably low charges, allowing the compression of the electron bunches to a few femto-seconds (nominal 200 pC mode) and even towards the atto-second range (short bunch 10 pC mode). A high precision charge measurement turns out to be a challenge, especially in the presence of dark currents, which may occur from high gradient RF gun and accelerating structure operation. In response to this challenge, a higher sensitivity charge transformer and new beam charge monitor electronics were developed in collaboration between Bergoz Instrumentation and PSI. The Turbo-ICT captures sub-pC bunch charge thanks to a new magnetic alloy exhibiting very low core loss. Transmission over a carrier using narrow-band cable television technique preserves the signal integrity from the Turbo-ICT to the BCM-RF. Electro-magnetic and RF interferences are strongly attenuated; the dark current signal is suppressed. First beam test results, which have been performed at the SwissFEL Test Injector Facility (STIF), are presented in this contribution.

TUPA15

Beam Postion Monitor for Energy Recovery Linac

pick-up, linac, vacuum, monitoring

361

I. Pinayev
BNL, Upton, Long Island, New York, USA

Funding: This work is supported by US Department of Energy.
The energy recovery linacs have co-propagating beams in the same vacuum vessel. These beams can have different trajectories, which should be distinguished by beam position monitors (BPM). In this paper we present a concept of BPM utilizing the phase information for calculation individual position of each of the two beams (accelerating and decelerating). The practical realizations are presented and achievable accuracy is estimated.

TUPA16

HOM Choice Study with Test Electronics for use as Beam Position Diagnostics in 3.9 GHz Accelerating Cavities in FLASH

cavity, HOM, dipole, electron

364

N. Baboi, B. Lorbeer, P. Zhang
DESY, Hamburg, Germany
N. Eddy, B.J. Fellenz, M. Wendt
Fermilab, Batavia, USA

Funding: Work supported in part by the European Commission within the Framework Programme 7, Grant Agreement 227579
Higher Order Modes (HOM) excited by the beam in the 3.9 GHz accelerating cavities in FLASH can be used for beam position diagnostics, as in a cavity beam position monitor. Previous studies of the modal choices within the complicated spectrum have revealed several options*: cavity modes with high coupling to the beam, and therefore with the potential for better position resolution, but which are propagating within all 4 cavities, and modes localized in the cavities or the beam pipes, which can give localized position information, but which provide worse resolution. For a better characterization of these options, test electronics has been built, which can down convert various frequencies between about 4 and 9 GHz to 70 MHz. The performance of various 20 MHz bands has been estimated. The best resolution of 20 μm was found for some propagating modes. Based on this study one band at ca. 5 GHz was chosen for high resolution position monitoring and a band at ca. 9 GHz for localized monitoring.
* N. Baboi et al., SRF2011, Chicago, IL, US

TUPA17

TPS BPM Electronics Performance Measurement and Statistics

FPGA, EPICS, booster, controls

369

P.C. Chiu, K.T. Hsu, K.H. Hu, C.H. Kuo
NSRRC, Hsinchu, Taiwan

The new BPM electronics Libera Brilliance Plus are developed for Taiwan Photon Source (TPS) which is a 3 GeV synchrotron light source constructed at NSRRC. This new BPM electronics can accommodate four BPM modules with integrated FPGA-based hardware. The preliminary test for the first arrival unit had been performed in the TLS (Taiwan Light Source) and had shown nearly equal performance compared with Libera Brilliance. The extra 75 sets had been delivered in 2011 and 2012. Performance of each unit are individually tested and measured.

TUPA19

First Tests of a Low Charge MTCA-based Electronics for Button and Strip-line BPM at FLASH

detector, timing, electron, operation

378

B. Lorbeer, N. Baboi, F. Schmidt-Föhre
DESY, Hamburg, Germany

Current FEL based light sources foresee operation with very short electron bunches. These can be obtained with charges of 100pC and lower. The specified charge range for FLASH, DESY, Hamburg goes from 100pC up to 1nC. The electronics currently installed at button and stripline BPMs of FLASH have been designed for best performance at higher charges and have reached their limits. Currently a new type of electronics is being developed at DESY to overcome these limitations. These electronics is/are conforming with the uTCA for physics standard(ref). This paper describes the next generation of FLASH BPM electronics suitable for button and stripline BPM. Furthermore the first measurement results taken with beam at FLASH, DESY are presented here.

TUPA23

Performance of a Downconverter Test-electronics with MTCA-based Digitizers for Beam Position Monitoring in 3.9 GHz Accelerating Cavities

HOM, electron, cavity, monitoring

386

T. Wamsat, N. Baboi, B. Lorbeer
DESY, Hamburg, Germany
P. Zhang
UMAN, Manchester, United Kingdom

Beam excited higher order modes (HOM) in 3.9GHz accelerating cavities at the European XFEL are planned to be used for beam position monitoring. The selected HOMs are located around 5440MHz and 9060MHz and are filtered in a bandwidth of 100MHz. A downconverter test electronics converts the HOMs to an intermediate frequency of 70MHz. The μTCA (Micro Telecommunications Computing Architecture) standard will be used for the XFEL. Thus it is important to have a performance study of the downconverter test electronics using the μTCA digitizer card SIS8300. In the digitizer IF frequency of 70MHz is undersampled with a clock frequency of 108MS/s. The paper will present the performance of the digitizer together with the test-electronics. A comparison with a 216MS/s VME (Versa Module Eurocard) digitizer will be made.

TUPA25

Signal Transmission Characteristics in Stripline-Type Beam Position Monitor

coupling, impedance, 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.

TUPA26

Development of New BPM Electronics for the Swiss Light Source

FPGA, controls, feedback, hardware

399

W. Koprek, R. Baldinger, R. Ditter, B. Keil, G. Marinkovic, M. Roggli, M. Stadler
PSI, Villigen PSI, Switzerland

PSI is currently developing new BPM electronics for the Swiss Light Source (SLS). Although the present "DBPM1" system that was designed 12 years ago still allows to achieve excellent beam stability and uptime, the development of a new system is motivated by long-term maintenance, improved performance in line with increasing user requirements, and new features and functionality provided by latest electronics technology. The new electronics is based on a generic modular BPM electronics platform developed by PSI that will also be used for linac based FELs like European XFEL and SwissFEL. The hardware and firmware architecture of the present prototypes as well as first test results will be presented.

TUPA27

Beam Test Results of Undulator Cavity BPM Electronics for the European XFEL

cavity, pick-up, undulator, feedback

404

M. Stadler, R. Baldinger, R. Ditter, B. Keil, R. Kramert, G. Marinkovic, M. Roggli
PSI, Villigen PSI, Switzerland
D. Lipka, D. Nölle, M. Pelzer, S. Vilcins
DESY, Hamburg, Germany

Funding: Work supported by Swiss State Secretariat for Education and Research SER
The European X-ray Free Electron Laser (E-XFEL) will use dual-resonator cavity BPMs (CBPMs) in the SASE undulators to measure and stabilize the beam trajectory. The BPM electronics is developed by PSI, while the pickup mechanics is developed by DESY. First beam tests with three adjacent pickups have been performed. The system architecture and algorithms, achieved performance and noise correlation measurements of the present electronics prototypes will be presented.