IBIC2013 - List of Keywords (SPS)

Paper	Title	Other Keywords	Page
MOPC17	Calibration of a Non-Linear Beam Position Monitor Electronics by Switching Electrode Signals	BPM, beam-position, LHC, CERN	85
	M. Gasior CERN, Geneva, Switzerland
	Button electrode signals from beam position monitors embedded into new LHC collimators will be individually processed with front-end electronics based on compensated diode detectors and digitized with 24-bit audio-range ADCs. This scheme allows sub-micrometre beam orbit resolution to be achieved with simple hardware and no external timing. As the diode detectors only operate in a linear regime with large amplitude signals, offset errors of the electronics cannot be calibrated in the classical way with no input. This paper describes the algorithms developed to calibrate the offset and gain asymmetry of these nonlinear electronic channels. Presented algorithm application examples are based on measurements performed with prototype diode orbit systems installed on the CERN SPS and LHC machines.

MOPC18	Development of a High Dynamic Range Beam Position Measurement System Using Logarithmic Amplifiers for the SPS at CERN	injection, beam-position, proton, CERN	89
	J.L. Gonzalez, T.B. Bogey, C. Deplano, J.-J. Savioz CERN, Geneva, Switzerland
	A new Front-End electronics, based on Logarithmic Amplifiers, is currently being developed for the CERN SPS Multi Orbit POsition System (MOPOS). The aim is to resolve the multi-batch structure of the beams and cope with their large intensity range (> 70 dB). Position and intensity signals are digitized in the Front-End electronics installed in the tunnel. The data are then transmitted over a serial fibre-optic link to a VME Digital Acquisition board located in surface buildings. A first prototype, equipped with a calibration system, has been successfully tested on the SPS under different beam conditions, including single bunch, 25ns and 50ns bunch trains. The system architecture and the first beam measurements are reported in this paper.
	Poster MOPC18 [4.013 MB]

MOPC28	The Hardware Implementation of the CERN SPS Ultrafast Feedback Processor Demonstrator	feedback, controls, FIR, CERN	124
	J.E. Dusatko, J.M. Cesaratto, J.D. Fox, J.J. Olsen, C.H. Rivetta SLAC, Menlo Park, 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) An ultrafast 4GSa/s transverse feedback processor has been developed for proof-of-concept studies of feedback control of e-cloud driven and transverse mode coupled intra-bunch instabilities in the CERN SPS. This system consists of a high-speed ADC on the front end and equally fast DAC on the back end. All control and signal processing is implemented in FPGA logic. This system is capable of taking up to 16 sample slices across a single SPS bunch and processing each slice individually within a reconfigurable signal processor. This demonstrator system is a rapidly developed prototype, consisting of both commercial and custom-design components. It can stabilize the motion of a single particle bunch using closed loop feedback. The system can also run open loop as a high-speed arbitrary waveform generator and contains diagnostic features including a special ADC snapshot capture memory. This paper describes the overall system, the feedback processor and focuses on the hardware architecture, design and implementation.
	Poster MOPC28 [1.684 MB]

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

TUBL2	A 4 GS/s Feedback Processing System for Control of Intra-Bunch Instabilities	feedback, controls, kicker, injection	323
	J.D. Fox, J.M. Cesaratto, J.E. Dusatko, J.J. Olsen, K.M. Pollock, C.H. Rivetta, O. Turgut SLAC, Menlo Park, 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) We present the architecture and implementation overview of a digital signal processing system developed to study control of Electron-Cloud and Transverse Mode coupling instabilities in the CERN SPS. The system is based on a reconfigurable processing architecture which samples vertical bunch motion and applies correction signals at a 4 GS/s rate, allowing 16 samples across a single 5 ns SPS RF bucket. The system requires wideband beam pickups and a vertical kicker structure with GHz bandwidth. This demonstration system implements a general purpose 16 tap FIR control filter for each sample. We present results from SPS machine studies showing the impact of wideband feedback to excite/damp internal modes of vertical motion as well as stabilize an unstable beam. These results highlight the challenges of intra-bunch feedback and show proof of principle feasibility of the architecture.
	Slides TUBL2 [12.154 MB]

TUBL3	A Multiband-Instability-Monitor for High-Frequency Intra-Bunch Beam Diagnostics	LHC, CERN, synchrotron, pick-up	327
	R.J. Steinhagen CERN, Geneva, Switzerland M.J. Boland, T.G. Lucas The University of Melbourne, Melbourne, Australia
	To provide the best possible luminosity, even higher beam intensities are needed in the Large Hadron Collider (LHC) and in its injector chain. This is fundamentally limited by self-amplifying beam instabilities, intrinsic to unavoidable imperfections in accelerators. Traditionally, intra-bunch or head-tail particle motion is measured using fast digitizers, which even using state-of-the-art technology are limited in their effective intra-bunch position resolution to few tens of um in the multi-GHz regime. Oscillations at this scale cause partial or total loss of the beam due to the tight transverse constraints imposed by the LHC collimation system. To improve on the present signal processing, a prototype system has been designed, constructed and tested at the CERN Super-Proton-Synchrotron (SPS) and later on LHC. The system splits the signal into multiple equally-spaced narrow frequency bands that are processed and analysed in parallel. Working with narrow-band signals in frequency-domain permits the use of much higher resolution analogue-to-digital-converters that can be used to resolve nm-scale particle motion already during the onset of instabilities.
	Slides TUBL3 [3.165 MB]

TUPF03	Performance Assessment of Wire-Scanners at CERN	LHC, CERN, laser, synchrotron	499
	G. Baud, B. Dehning, J. Emery, J-J. Gras, A. Guerrero, E.P. Piselli CERN, Geneva, Switzerland
	This article describes the current fast wire-scanner devices installed in circular accelerators at CERN with an emphasis of the error studies carried out during the last two runs. At present the wire-scanners have similar acquisition systems but are varied in terms of mechanics. Several measurement campaigns were performed aimed at establishing optimal operational settings and to identify and assess systematic errors. In several cases the results led to direct performance improvements while in others this helped in defining the requirements for new detectors.
	Poster TUPF03 [1.040 MB]

WEPC11	Radiation Resistance Testing of Commercial Components for the New SPS Beam Position Measurement System	radiation, CERN, beam-position, BPM	686
	C. Deplano, J. Albertone, T.B. Bogey, J.L. Gonzalez, J.-J. Savioz CERN, Geneva, Switzerland
	A new Front-End (FE) electronics is under development for the SPS Multi Orbit POsition System (MOPOS). To cover the large dynamic range of beam intensities (70dB) to be measured in the SPS, the beam position monitor signals are processed using logarithmic amplifiers. They are then digitized locally and transmitted via optical fibers over long distances (up to 1km) to VME acquisition boards located in surface buildings. The FE board is designed to be located in the SPS tunnel, where it must cope with a radiation dose rate of up to 100 Gy per year. Analogue components, such as Logarithmic Amplifiers, ADC-Drivers and Voltage regulators, have been tested at PSI for radiation hardness, while several families of bidirectional SFP, both single-fiber and double-fiber, have been tested at both PSI and CNRAD. This paper gives a description of the overall system architecture and presents the results of the radiation hardness tests in detail.
	Poster WEPC11 [3.299 MB]

WEPC12	Evaluation of Strip-line Pick-up System for the SPS Wideband Transverse Feedback System	pick-up, feedback, transverse, coupling	690
	G. Kotzian, W. Höfle, R.J. Steinhagen, D. Valuch, U. Wehrle CERN, Geneva, Switzerland
	The proposed SPS Wideband Transverse Feedback system requires a wide-band pick-up system to be able to detect intra-bunch motion within the SPS proton bunches, captured and accelerated in a 200 MHz bucket. We present the electro-magnetic design of transverse beam position pick-up options optimised for installation in the SPS and evaluate their performance reach with respect to direct time domain sampling of the intra-bunch motion. The analysis also discusses the achieved subsystem responses of the associated cabling with new low dispersion smooth wall cables, wide-band generation of intensity and position signals by means of 180 degree RF hybrids as well as passive techniques to electronically suppress the beam offset signal, needed to optimise the dynamic range and position resolution of the planned digital intra-bunch feedback system.

Paper

Title

Other Keywords

Page

MOPC17

Calibration of a Non-Linear Beam Position Monitor Electronics by Switching Electrode Signals

BPM, beam-position, LHC, CERN

85

M. Gasior
CERN, Geneva, Switzerland

Button electrode signals from beam position monitors embedded into new LHC collimators will be individually processed with front-end electronics based on compensated diode detectors and digitized with 24-bit audio-range ADCs. This scheme allows sub-micrometre beam orbit resolution to be achieved with simple hardware and no external timing. As the diode detectors only operate in a linear regime with large amplitude signals, offset errors of the electronics cannot be calibrated in the classical way with no input. This paper describes the algorithms developed to calibrate the offset and gain asymmetry of these nonlinear electronic channels. Presented algorithm application examples are based on measurements performed with prototype diode orbit systems installed on the CERN SPS and LHC machines.

MOPC18

Development of a High Dynamic Range Beam Position Measurement System Using Logarithmic Amplifiers for the SPS at CERN

injection, beam-position, proton, CERN

89

J.L. Gonzalez, T.B. Bogey, C. Deplano, J.-J. Savioz
CERN, Geneva, Switzerland

A new Front-End electronics, based on Logarithmic Amplifiers, is currently being developed for the CERN SPS Multi Orbit POsition System (MOPOS). The aim is to resolve the multi-batch structure of the beams and cope with their large intensity range (> 70 dB). Position and intensity signals are digitized in the Front-End electronics installed in the tunnel. The data are then transmitted over a serial fibre-optic link to a VME Digital Acquisition board located in surface buildings. A first prototype, equipped with a calibration system, has been successfully tested on the SPS under different beam conditions, including single bunch, 25ns and 50ns bunch trains. The system architecture and the first beam measurements are reported in this paper.

Poster MOPC18 [4.013 MB]

MOPC28

The Hardware Implementation of the CERN SPS Ultrafast Feedback Processor Demonstrator

feedback, controls, FIR, CERN

124

J.E. Dusatko, J.M. Cesaratto, J.D. Fox, J.J. Olsen, C.H. Rivetta
SLAC, Menlo Park, 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)
An ultrafast 4GSa/s transverse feedback processor has been developed for proof-of-concept studies of feedback control of e-cloud driven and transverse mode coupled intra-bunch instabilities in the CERN SPS. This system consists of a high-speed ADC on the front end and equally fast DAC on the back end. All control and signal processing is implemented in FPGA logic. This system is capable of taking up to 16 sample slices across a single SPS bunch and processing each slice individually within a reconfigurable signal processor. This demonstrator system is a rapidly developed prototype, consisting of both commercial and custom-design components. It can stabilize the motion of a single particle bunch using closed loop feedback. The system can also run open loop as a high-speed arbitrary waveform generator and contains diagnostic features including a special ADC snapshot capture memory. This paper describes the overall system, the feedback processor and focuses on the hardware architecture, design and implementation.

Poster MOPC28 [1.684 MB]

MOPF07

Turn by Turn Profile Monitors for the CERN SPS and LHC

LHC, OTR, optics, proton

216

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

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

TUBL2

A 4 GS/s Feedback Processing System for Control of Intra-Bunch Instabilities

feedback, controls, kicker, injection

323

J.D. Fox, J.M. Cesaratto, J.E. Dusatko, J.J. Olsen, K.M. Pollock, C.H. Rivetta, O. Turgut
SLAC, Menlo Park, 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)
We present the architecture and implementation overview of a digital signal processing system developed to study control of Electron-Cloud and Transverse Mode coupling instabilities in the CERN SPS. The system is based on a reconfigurable processing architecture which samples vertical bunch motion and applies correction signals at a 4 GS/s rate, allowing 16 samples across a single 5 ns SPS RF bucket. The system requires wideband beam pickups and a vertical kicker structure with GHz bandwidth. This demonstration system implements a general purpose 16 tap FIR control filter for each sample. We present results from SPS machine studies showing the impact of wideband feedback to excite/damp internal modes of vertical motion as well as stabilize an unstable beam. These results highlight the challenges of intra-bunch feedback and show proof of principle feasibility of the architecture.

Slides TUBL2 [12.154 MB]

TUBL3

A Multiband-Instability-Monitor for High-Frequency Intra-Bunch Beam Diagnostics

LHC, CERN, synchrotron, pick-up

327

R.J. Steinhagen
CERN, Geneva, Switzerland
M.J. Boland, T.G. Lucas
The University of Melbourne, Melbourne, Australia

To provide the best possible luminosity, even higher beam intensities are needed in the Large Hadron Collider (LHC) and in its injector chain. This is fundamentally limited by self-amplifying beam instabilities, intrinsic to unavoidable imperfections in accelerators. Traditionally, intra-bunch or head-tail particle motion is measured using fast digitizers, which even using state-of-the-art technology are limited in their effective intra-bunch position resolution to few tens of um in the multi-GHz regime. Oscillations at this scale cause partial or total loss of the beam due to the tight transverse constraints imposed by the LHC collimation system. To improve on the present signal processing, a prototype system has been designed, constructed and tested at the CERN Super-Proton-Synchrotron (SPS) and later on LHC. The system splits the signal into multiple equally-spaced narrow frequency bands that are processed and analysed in parallel. Working with narrow-band signals in frequency-domain permits the use of much higher resolution analogue-to-digital-converters that can be used to resolve nm-scale particle motion already during the onset of instabilities.

Slides TUBL3 [3.165 MB]

TUPF03

Performance Assessment of Wire-Scanners at CERN

LHC, CERN, laser, synchrotron

499

G. Baud, B. Dehning, J. Emery, J-J. Gras, A. Guerrero, E.P. Piselli
CERN, Geneva, Switzerland

This article describes the current fast wire-scanner devices installed in circular accelerators at CERN with an emphasis of the error studies carried out during the last two runs. At present the wire-scanners have similar acquisition systems but are varied in terms of mechanics. Several measurement campaigns were performed aimed at establishing optimal operational settings and to identify and assess systematic errors. In several cases the results led to direct performance improvements while in others this helped in defining the requirements for new detectors.

Poster TUPF03 [1.040 MB]

WEPC11

Radiation Resistance Testing of Commercial Components for the New SPS Beam Position Measurement System

radiation, CERN, beam-position, BPM

686

C. Deplano, J. Albertone, T.B. Bogey, J.L. Gonzalez, J.-J. Savioz
CERN, Geneva, Switzerland

A new Front-End (FE) electronics is under development for the SPS Multi Orbit POsition System (MOPOS). To cover the large dynamic range of beam intensities (70dB) to be measured in the SPS, the beam position monitor signals are processed using logarithmic amplifiers. They are then digitized locally and transmitted via optical fibers over long distances (up to 1km) to VME acquisition boards located in surface buildings. The FE board is designed to be located in the SPS tunnel, where it must cope with a radiation dose rate of up to 100 Gy per year. Analogue components, such as Logarithmic Amplifiers, ADC-Drivers and Voltage regulators, have been tested at PSI for radiation hardness, while several families of bidirectional SFP, both single-fiber and double-fiber, have been tested at both PSI and CNRAD. This paper gives a description of the overall system architecture and presents the results of the radiation hardness tests in detail.

Poster WEPC11 [3.299 MB]

WEPC12

Evaluation of Strip-line Pick-up System for the SPS Wideband Transverse Feedback System

pick-up, feedback, transverse, coupling

690

G. Kotzian, W. Höfle, R.J. Steinhagen, D. Valuch, U. Wehrle
CERN, Geneva, Switzerland

The proposed SPS Wideband Transverse Feedback system requires a wide-band pick-up system to be able to detect intra-bunch motion within the SPS proton bunches, captured and accelerated in a 200 MHz bucket. We present the electro-magnetic design of transverse beam position pick-up options optimised for installation in the SPS and evaluate their performance reach with respect to direct time domain sampling of the intra-bunch motion. The analysis also discusses the achieved subsystem responses of the associated cabling with new low dispersion smooth wall cables, wide-band generation of intensity and position signals by means of 180 degree RF hybrids as well as passive techniques to electronically suppress the beam offset signal, needed to optimise the dynamic range and position resolution of the planned digital intra-bunch feedback system.