IBIC2014 - List of Keywords (coupling)

Paper	Title	Other Keywords	Page
MOPF16	CERN-SPS Wire Scanner Impedence and Wire Heating Studies	simulation, vacuum, electromagnetic-fields, emittance	88
	E. Piselli, O.E. Berrig, F. Caspers, B. Dehning, J. Emery, M. Hamani, J. Kuczerowski, B. Salvant, R.S. Sautier, R. Veness, C. Vuitton, C. Zannini CERN, Geneva, Switzerland
	This article describes a study performed on one of the SPS vertical rotational wire scanners in order to investigate the breakage of the wire, which occurred on several occasions during the last year of operation. The thermionic emission current of the wire was measured to evaluate temperature changes, and was observed to rise significantly as the wire approached the ultimate LHC beam in the SPS, indicating the possibility of strong coupling between the beam’s electromagnetic field and the wire. Different laboratory measurements, complemented by CST Microwave Studio simulations, have therefore been performed to try and understand the RF modes responsible for this heating. These results are presented here, along with the subsequent modifications adopted on all of the operational SPS wire scanners.
	Poster MOPF16 [0.747 MB]
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TUTUB1	Managing Electromagnetic Interference in Large Instrumentation Environments	instrumentation, impedance, network, shielding	224
	M.E. Gruchalla URS, Albuquerque, New Mexico, USA M. Thuot LANL, Los Alamos, New Mexico, USA
	Funding: Work supported by the US Department of Energy Implementing high-quality measurement systems in large test environments presents a number of unique challenges. And, these challenges are made even more interesting where new instrumentation systems are being implemented in existing legacy environments where there is little opportunity to modify the infrastructure. Often, Electromagnetic Interference (EMI) is encountered. This interference may be simply an annoyance were sufficiently low that data integrity is not severely compromised, but in many cases, perhaps most, EMI is so severe as to totally obscure the signals of interest. Various sources of EMI and common points of entry of are reviewed. Means of mitigation of EMI in the design and implementation of instrumentation systems in legacy environments are presented. Common sources of EMI potentially introduced by the instrumentation systems themselves are examined, and means of design to mitigate such self-induce interference are examined. Real-life examples are provided to demonstrate the EMI issues, and the affect of mitigation. It’s all about the current – pretty much!
	Slides TUTUB1 [5.452 MB]
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TUPF03	Overview of the Geometrical Non-Linear Effects of Button BPMs and Methodology for Their Efficient Suppression	pick-up, simulation, storage-ring, vacuum	298
	A.A. Nosych, U. Iriso, A. Olmos ALBA-CELLS Synchrotron, Cerdanyola del Vallès, Spain M. Wendt CERN, Geneva, Switzerland
	This paper describes an overview of the geometric non-linear effects common to beam position monitors (BPMs) installed in the accelerators and a methodology to correct for these effects. A typical characteristic curve of a pick-up is linear within a limited range from the BPM origin. At larger offsets the non-linearity of the curve is more pronounced and gets worse if the button diameter is small with respect to the beam pipe diameter. The general real-time linearization methods usually utilize linear correction combined with a simplistic polynomial, which may lead to inaccuracies in their limited application. We have developed a more rigorous methodology to suppress the non-linear effects of the BPMs through electromagnetic (EM) simulations and 2D fitting approximations. The focus is mainly on standard button pick-ups for the electron (ALBA) and proton machines (LHC).
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TUPF14	Newly Developed 6mm Buttons for the BPMs in the ESRF Low-Emittance-Ring	factory, simulation, vacuum, operation	346
	K.B. Scheidt ESRF, Grenoble, France
	For the small beam pipe of the BPMs in the LE-ring a development of 6mm button-UHV-feedthroughs was launched and has resulted in the delivery of a total of 27 prototypes from both the Kyocera and the PMB-ALCEN companies. These buttons are flat, without skirt, with a central pin of Molybdenum ending in a male SMA connector. Among these prototype units are versions with Copper, Steel and Molybdenum material for the button itself, with the aim of assessing possible different heatload issues. All design considerations, that are compatible with a further button reduction to 4mm, will be presented next to issues of costs, mechanical tolerances and feasibility.
	Poster TUPF14 [1.420 MB]
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TUPD21	AC Coupling Studies and Circuit Model for Loss Monitor Ring	niobium, background, ion, simulation	455
	Z. Liu, J.L. Crisp, S.M. Lidia FRIB, East Lansing, Michigan, USA
	Funding: This material is based upon work supported by the U.S. Department of Energy Office of Science under Cooperative Agreement DE-SC0000661, the State of Michigan and Michigan State University. As a follow-up study to the initial design of FRIB Loss Monitor Ring (previously named Halo Monitor Ring [1]), we present recent results of coupling studies between the FRIB CW beam and the Loss Monitor Ring (LMR). While a ~33 kHz low-pass filter was proposed to attenuate high-frequency AC-coupled signals [1,2], the LMR current signal may still contain low frequency signals induced by the un-intercepted beam, for example, by the 50μs beam notch that repeats every 10ms. We use CST Microwave Studio to simulate the AC response of a Gaussian source signal and benchmarked it to analytical model. A circuit model for beam-notch-induced AC signal is deduced and should put a ~33pA (peak) bipolar pulse on the LMR at 100Hz repetition rate. Although its amplitude falls into our tolerable region, we could consider an extended background integration to eliminate this effect.
	Poster TUPD21 [1.201 MB]
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WEPF04	A Cryogenic Current Comparator for the Low Energy Antiproton Facitities at CERN	pick-up, cryogenics, feedback, 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.
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Paper

Title

Other Keywords

Page

MOPF16

CERN-SPS Wire Scanner Impedence and Wire Heating Studies

simulation, vacuum, electromagnetic-fields, emittance

88

E. Piselli, O.E. Berrig, F. Caspers, B. Dehning, J. Emery, M. Hamani, J. Kuczerowski, B. Salvant, R.S. Sautier, R. Veness, C. Vuitton, C. Zannini
CERN, Geneva, Switzerland

This article describes a study performed on one of the SPS vertical rotational wire scanners in order to investigate the breakage of the wire, which occurred on several occasions during the last year of operation. The thermionic emission current of the wire was measured to evaluate temperature changes, and was observed to rise significantly as the wire approached the ultimate LHC beam in the SPS, indicating the possibility of strong coupling between the beam’s electromagnetic field and the wire. Different laboratory measurements, complemented by CST Microwave Studio simulations, have therefore been performed to try and understand the RF modes responsible for this heating. These results are presented here, along with the subsequent modifications adopted on all of the operational SPS wire scanners.

Poster MOPF16 [0.747 MB]

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

TUTUB1

Managing Electromagnetic Interference in Large Instrumentation Environments

instrumentation, impedance, network, shielding

224

M.E. Gruchalla
URS, Albuquerque, New Mexico, USA
M. Thuot
LANL, Los Alamos, New Mexico, USA

Funding: Work supported by the US Department of Energy
Implementing high-quality measurement systems in large test environments presents a number of unique challenges. And, these challenges are made even more interesting where new instrumentation systems are being implemented in existing legacy environments where there is little opportunity to modify the infrastructure. Often, Electromagnetic Interference (EMI) is encountered. This interference may be simply an annoyance were sufficiently low that data integrity is not severely compromised, but in many cases, perhaps most, EMI is so severe as to totally obscure the signals of interest. Various sources of EMI and common points of entry of are reviewed. Means of mitigation of EMI in the design and implementation of instrumentation systems in legacy environments are presented. Common sources of EMI potentially introduced by the instrumentation systems themselves are examined, and means of design to mitigate such self-induce interference are examined. Real-life examples are provided to demonstrate the EMI issues, and the affect of mitigation. It’s all about the current – pretty much!

Slides TUTUB1 [5.452 MB]

Export •

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

TUPF03

Overview of the Geometrical Non-Linear Effects of Button BPMs and Methodology for Their Efficient Suppression

pick-up, simulation, storage-ring, vacuum

298

A.A. Nosych, U. Iriso, A. Olmos
ALBA-CELLS Synchrotron, Cerdanyola del Vallès, Spain
M. Wendt
CERN, Geneva, Switzerland

This paper describes an overview of the geometric non-linear effects common to beam position monitors (BPMs) installed in the accelerators and a methodology to correct for these effects. A typical characteristic curve of a pick-up is linear within a limited range from the BPM origin. At larger offsets the non-linearity of the curve is more pronounced and gets worse if the button diameter is small with respect to the beam pipe diameter. The general real-time linearization methods usually utilize linear correction combined with a simplistic polynomial, which may lead to inaccuracies in their limited application. We have developed a more rigorous methodology to suppress the non-linear effects of the BPMs through electromagnetic (EM) simulations and 2D fitting approximations. The focus is mainly on standard button pick-ups for the electron (ALBA) and proton machines (LHC).

Export •

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

TUPF14

Newly Developed 6mm Buttons for the BPMs in the ESRF Low-Emittance-Ring

factory, simulation, vacuum, operation

346

K.B. Scheidt
ESRF, Grenoble, France

For the small beam pipe of the BPMs in the LE-ring a development of 6mm button-UHV-feedthroughs was launched and has resulted in the delivery of a total of 27 prototypes from both the Kyocera and the PMB-ALCEN companies. These buttons are flat, without skirt, with a central pin of Molybdenum ending in a male SMA connector. Among these prototype units are versions with Copper, Steel and Molybdenum material for the button itself, with the aim of assessing possible different heatload issues. All design considerations, that are compatible with a further button reduction to 4mm, will be presented next to issues of costs, mechanical tolerances and feasibility.

Poster TUPF14 [1.420 MB]

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

TUPD21

AC Coupling Studies and Circuit Model for Loss Monitor Ring

niobium, background, ion, simulation

455

Z. Liu, J.L. Crisp, S.M. Lidia
FRIB, East Lansing, Michigan, USA

Funding: This material is based upon work supported by the U.S. Department of Energy Office of Science under Cooperative Agreement DE-SC0000661, the State of Michigan and Michigan State University.
As a follow-up study to the initial design of FRIB Loss Monitor Ring (previously named Halo Monitor Ring [1]), we present recent results of coupling studies between the FRIB CW beam and the Loss Monitor Ring (LMR). While a ~33 kHz low-pass filter was proposed to attenuate high-frequency AC-coupled signals [1,2], the LMR current signal may still contain low frequency signals induced by the un-intercepted beam, for example, by the 50μs beam notch that repeats every 10ms. We use CST Microwave Studio to simulate the AC response of a Gaussian source signal and benchmarked it to analytical model. A circuit model for beam-notch-induced AC signal is deduced and should put a ~33pA (peak) bipolar pulse on the LMR at 100Hz repetition rate. Although its amplitude falls into our tolerable region, we could consider an extended background integration to eliminate this effect.

Poster TUPD21 [1.201 MB]

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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, cryogenics, feedback, 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)