IBIC2013 - List of Keywords (impedance)

Paper	Title	Other Keywords	Page
MOPC24	Design Of The Stripline BPM For The Advanced Photoinjector Experiment	BPM, simulation, coupling, diagnostics	108
	S. De Santis, M.J. Chin, D. Filippetto, W.E. Norum, Z. Paret, G.J. Portmann, F. Sannibale, R.P. Wells LBNL, Berkeley, California, USA
	Funding: Work supported by the U.S. Department of Energy under Contract No. DE-AC02-05CH11231 We describe the design, bench testing, and initial commissioning of the shorted striplines beam position monitors used in the Advanced Photoinjector Experiment (APEX) at Lawrence Berkeley National Laboratory. Our BPM's are characterized by extreme compactness, being designed to fit in the vacuum chamber of the quadrupole magnets, with only a short portion including the RF feedthroughs occupying additional beam pipe length. In this paper we illustrate the design process, which included extensive 3D computer simulations, the bench testing of prototype and final components, and the first measurements with beam. The readout electronics is also described.

MOPF23	Quantifying Dissipated Power From Wake Field Losses in Diagnostics Structures	simulation, resonance, single-bunch, DIAMOND	259
	A.F.D. Morgan, G. Rehm Diamond, Oxfordshire, United Kingdom
	As a charged particle beam passes through structures, wake fields can deposit a fraction of the energy carried by the beam as characterised by the wake loss factor. Some part of the deposited energy will be emitted into the beam pipe, some part can be coupled out of signal ports and some part will be absorbed by the materials of the structures. With increasingly higher stored currents, we require a better understanding of where all the energy deposited by wake losses ends up in order to avoid damaging components. This is of particular concern for diagnostics structures as they are often designed to couple a small fraction of energy from the beam, which makes them susceptible to thermal damage due to increased localised losses. We will detail the simulation and analysis approach which we have developed to quantify power deposition within structures. As an example the analysis of a beam position monitor pickup block of the Diamond storage ring is shown.
	Poster MOPF23 [0.249 MB]

MOPF24	Magnetic Materials for Current Transformers	CERN, vacuum, damping, GSI	263
	S. Aguilera, P. Odier, R. Ruffieux CERN, Geneva, Switzerland
	At CERN, the circulating beam current measurement is provided by two types of transformers, the Direct Current Current Transformers (DCCT) and the Fast Beam Current Transformers (FBCT). Each type of transformer requires different magnetic characteristics regarding parameters such as permeability, coercivity and shape of the magnetization curve. Each transformer is built based on toroidal cores of a magnetic material which gives these characteristics. For example, DCCTs consist of three cores, two for the measurement of the DC component and one for the AC component. In order to study the effect of changes in these parameters on the current transformers, several interesting raw materials based on their as-cast properties were selected with the annealing process used to tune their properties for the individual needs of each transformer. First annealing tests show that the magnetization curve, and therefore the permeability, of the material can be modified, opening the possibility for building and studying a variety of transformer cores.
	Poster MOPF24 [1.185 MB]

TUPC07	Design and Impedance Optimization of the SIRIUS BPM Button	BPM, vacuum, storage-ring, longitudinal	365
	H.O.C. Duarte, S.R. Marques, L. Sanfelici LNLS, Campinas, Brazil
	Design of several BPM Buttons is presented with detail impedance, heat transfer and mechanical analysis. Special attention is given to the application of ceramics as materials with low relative permittivity inside of the BPM Button and to the geometric shape of the BPM Button. The heat dissipation is evaluated based on the loss factor calculated for a 2.65mm bunch length. The narrow-band impedance is discussed and its dependence on applied ceramic materials is compared.
	Poster TUPC07 [1.715 MB]

TUPC08	Design and Impedance Optimization of the LNLS-UVX Longitudinal Kicker Cavity	longitudinal, kicker, feedback, synchrotron	369
	L. Sanfelici, H.O.C. Duarte, S.R. Marques LNLS, Campinas, Brazil
	Performance evolution of parameters achieved during the electromagnetic design of the longitudinal kicker cavity for the LNLS UVX storage ring is presented. The effort on the electromagnetic optimization process of the heavily loaded cavity has been made to reach the required electrodynamic parameters of the kicker. The results for three different geometries are compared and a good compromise between the longitudinal shunt impedance and the effect of the longitudinal Higher Order Modes (HOM’s) on beam stability has been found.
	Poster TUPC08 [1.365 MB]

TUPC11	Beam-Based Measurement of ID Taper Impedance at Diamond	transverse, vacuum, simulation, BPM	380
	V.V. Smaluk, R. Bartolini, R.T. Fielder, G. Rehm Diamond, Oxfordshire, United Kingdom
	New insertion devices (IDs) are being designed now for a Diamond upgrade. One of the important topics of the design is the coupling impedance of the ID vacuum chamber movable tapers. To get a complete and reliable information of the impedance, analytical estimations, numerical simulation and beam-based measurement have been performed. The impedance of an existing ID taper geometrically similar to the new one has been measured using the orbit bump method. It turns out that in spite of the small magnitude (a few um) of orbit distortion to be observed in this case, the BPM resolution is sufficient for this measurement. The measurement results in comparison with simulation data are discussed in this paper.

TUPC12	Status of the Stripline Beam Position Monitor Development for the CLIC Drive Beam	BPM, CLIC, beam-position, CTF3	384
	A. Benot-Morell, L. Søby, M. Wendt CERN, Geneva, Switzerland A. Benot-Morell, A. Faus-Golfe IFIC, Valencia, Spain J.M. Nappa, S. Vilalte IN2P3-LAPP, Annecy-le-Vieux, France S.R. Smith SLAC, Menlo Park, California, USA
	Funding: MINECO contract FPA2010-21456-C02-01, SEIC-2010-00028, U.S. Department of Energy contract DE-AC02-76SF00515 In collaboration with SLAC, LAPP and IFIC, a first prototype of a strip-line Beam Position Monitor (BPM) for the CLIC Drive Beam and its associated readout electronics has been successfully tested in the CLIC Test Facility linac (CTF3) at CERN. In addition, a modified prototype with downstream terminated strip-lines is under development to better suppress any unwanted RF signal interference. This paper presents the results of the beam tests, the most relevant design aspects for the modified strip-line BPM version and its expected performance.
	Poster TUPC12 [1.729 MB]

TUPC28	Strip Line Monitor design for the ISIS Proton Synchrotron using the FEA program HFSS	coupling, kicker, feedback, scattering	435
	S.J. Payne STFC/RAL/ISIS, Chilton, Didcot, Oxon, United Kingdom
	This paper reports the development of a strip line monitor for the ISIS accelerator main ring. The strip line is still in the design phase and the work reported here is the results of the FEA programme HFSS. The strip line will eventually form part of a beam instability feedback system and will be used to control instabilities both in the current ISIS machine and for all future ISIS upgrades where higher intensities and energies could be realised. The strip line consists of two pairs of 550mm by 160mm broad flat electrodes configured to allow damping in both the horizontal and vertical planes. The paper describes the efforts to achieve a bandwidth of >260MHz which will allow the feedback system deal with instabilities such as those caused by electron clouds. Design of the electrodes including matching of the feed throughs to the electrodes , concerns of materials for the electrode supports are considered. Also considered are methods used to improved inter-electrode decoupling (to better than -30db) . Results in the form of scattering parameters, smith charts, time domain reflectivity and shunt impedances will be presented.

WEPC17	Design and Simulation of Beam Position Monitor for the CADS Injector I Proton Linac	BPM, simulation, pick-up, linac	710
	Y.F. Sui, J.S. Cao, H.Z. Ma, Q. Ye, J. Yue IHEP, People's Republic of China
	Funding: Work supported by the National Natural Science Foundation of China (NO. 11205172) Beam Position Monitors (BPM) based on both capacitive and stripline pick-ups are designed for the China Accelerator Driven Subcritical system (C-ADS) Injector I proton LINAC. The BPM will be installed to measure the transverse beam position in the LINAC, of which the beam parameters are listed as current 10mA, energy 10MeV and the repetition frequency 325MHz. This contribution presents the status of the BPM design development and focuses on the design of the pick-ups and CST Particle Studio simulation results, including impedance, sensitivity, time domain, frequency domain response, etc. The main goal of the simulation is optimization of the mechanical design.

WEPC26	Pickup Electrode Electrodynamics Investigation	pick-up, LEFT, transverse, vacuum	742
	A. Kalinin STFC/DL/ASTeC, Daresbury, Warrington, Cheshire, United Kingdom
	Waves induced in a pickup by beam were investigated on a large scale model, using 10ps step in coaxial line as beam, and a differentiating capacitive probe. The probe signal was observed at 20GHz oscilloscope. In each of the front and rear transverse gaps between pickup electrode and wall (button pickup), a shorter-than-gap bunch excites a ‘plain-wave’ packet which length is of the order of gap length over c. Two packets are spaced by electrode length over c. The packets propagate along the electrode to a coaxial connector. At this low impedance common point each of the packets partially reflects back and partially passes into the opposite gap. The voltage appearing on the impedance excites two TEM-wave packets: one propagates backwards, another one propagates forward through connector. The connector output is sum of two such packets spaced the same as two incident packets. The packets propagating backwards reflect from the electrode open end, come back to the summing point and generate output in similar way. The same processes occur in a pickup with single gap electrodes (stripline pickup). This phenomenological picture can be used as a guide in pickup design and simulation.
	Poster WEPC26 [0.647 MB]

THBL1	RF Heating from Wake Losses in Diagnostics Structures	resonance, longitudinal, LHC, simulation	929
	E. Métral CERN, Geneva, Switzerland
	Heating of diagnostics structures (striplines, buttons, screen vessels, wire scanners etc) has been observed at many facilities with higher stored currents. Simulations of wake losses using 3D EM codes are regularly used to estimate the amount of power lost from the bunched beam but on its own this does not tell how much is radiated back into the beam pipe or transmitted into external ports and how much is actually being dissipated in the structure and where. This talk should introduce into the matter, summarise some of the observations at various facilities and illustrate what approaches of detailed simulations have been taken. summarizing a workshop at DLS (see http://tinyurl.com/wakeloss )
	Slides THBL1 [9.078 MB]

Paper

Title

Other Keywords

Page

MOPC24

Design Of The Stripline BPM For The Advanced Photoinjector Experiment

BPM, simulation, coupling, diagnostics

108

S. De Santis, M.J. Chin, D. Filippetto, W.E. Norum, Z. Paret, G.J. Portmann, F. Sannibale, R.P. Wells
LBNL, Berkeley, California, USA

Funding: Work supported by the U.S. Department of Energy under Contract No. DE-AC02-05CH11231
We describe the design, bench testing, and initial commissioning of the shorted striplines beam position monitors used in the Advanced Photoinjector Experiment (APEX) at Lawrence Berkeley National Laboratory. Our BPM's are characterized by extreme compactness, being designed to fit in the vacuum chamber of the quadrupole magnets, with only a short portion including the RF feedthroughs occupying additional beam pipe length. In this paper we illustrate the design process, which included extensive 3D computer simulations, the bench testing of prototype and final components, and the first measurements with beam. The readout electronics is also described.

MOPF23

Quantifying Dissipated Power From Wake Field Losses in Diagnostics Structures

simulation, resonance, single-bunch, DIAMOND

259

A.F.D. Morgan, G. Rehm
Diamond, Oxfordshire, United Kingdom

As a charged particle beam passes through structures, wake fields can deposit a fraction of the energy carried by the beam as characterised by the wake loss factor. Some part of the deposited energy will be emitted into the beam pipe, some part can be coupled out of signal ports and some part will be absorbed by the materials of the structures. With increasingly higher stored currents, we require a better understanding of where all the energy deposited by wake losses ends up in order to avoid damaging components. This is of particular concern for diagnostics structures as they are often designed to couple a small fraction of energy from the beam, which makes them susceptible to thermal damage due to increased localised losses. We will detail the simulation and analysis approach which we have developed to quantify power deposition within structures. As an example the analysis of a beam position monitor pickup block of the Diamond storage ring is shown.

Poster MOPF23 [0.249 MB]

MOPF24

Magnetic Materials for Current Transformers

CERN, vacuum, damping, GSI

263

S. Aguilera, P. Odier, R. Ruffieux
CERN, Geneva, Switzerland

At CERN, the circulating beam current measurement is provided by two types of transformers, the Direct Current Current Transformers (DCCT) and the Fast Beam Current Transformers (FBCT). Each type of transformer requires different magnetic characteristics regarding parameters such as permeability, coercivity and shape of the magnetization curve. Each transformer is built based on toroidal cores of a magnetic material which gives these characteristics. For example, DCCTs consist of three cores, two for the measurement of the DC component and one for the AC component. In order to study the effect of changes in these parameters on the current transformers, several interesting raw materials based on their as-cast properties were selected with the annealing process used to tune their properties for the individual needs of each transformer. First annealing tests show that the magnetization curve, and therefore the permeability, of the material can be modified, opening the possibility for building and studying a variety of transformer cores.

Poster MOPF24 [1.185 MB]

TUPC07

Design and Impedance Optimization of the SIRIUS BPM Button

BPM, vacuum, storage-ring, longitudinal

365

H.O.C. Duarte, S.R. Marques, L. Sanfelici
LNLS, Campinas, Brazil

Design of several BPM Buttons is presented with detail impedance, heat transfer and mechanical analysis. Special attention is given to the application of ceramics as materials with low relative permittivity inside of the BPM Button and to the geometric shape of the BPM Button. The heat dissipation is evaluated based on the loss factor calculated for a 2.65mm bunch length. The narrow-band impedance is discussed and its dependence on applied ceramic materials is compared.

Poster TUPC07 [1.715 MB]

TUPC08

Design and Impedance Optimization of the LNLS-UVX Longitudinal Kicker Cavity

longitudinal, kicker, feedback, synchrotron

369

L. Sanfelici, H.O.C. Duarte, S.R. Marques
LNLS, Campinas, Brazil

Performance evolution of parameters achieved during the electromagnetic design of the longitudinal kicker cavity for the LNLS UVX storage ring is presented. The effort on the electromagnetic optimization process of the heavily loaded cavity has been made to reach the required electrodynamic parameters of the kicker. The results for three different geometries are compared and a good compromise between the longitudinal shunt impedance and the effect of the longitudinal Higher Order Modes (HOM’s) on beam stability has been found.

Poster TUPC08 [1.365 MB]

TUPC11

Beam-Based Measurement of ID Taper Impedance at Diamond

transverse, vacuum, simulation, BPM

380

V.V. Smaluk, R. Bartolini, R.T. Fielder, G. Rehm
Diamond, Oxfordshire, United Kingdom

New insertion devices (IDs) are being designed now for a Diamond upgrade. One of the important topics of the design is the coupling impedance of the ID vacuum chamber movable tapers. To get a complete and reliable information of the impedance, analytical estimations, numerical simulation and beam-based measurement have been performed. The impedance of an existing ID taper geometrically similar to the new one has been measured using the orbit bump method. It turns out that in spite of the small magnitude (a few um) of orbit distortion to be observed in this case, the BPM resolution is sufficient for this measurement. The measurement results in comparison with simulation data are discussed in this paper.

TUPC12

Status of the Stripline Beam Position Monitor Development for the CLIC Drive Beam

BPM, CLIC, beam-position, CTF3

384

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

Funding: MINECO contract FPA2010-21456-C02-01, SEIC-2010-00028, U.S. Department of Energy contract DE-AC02-76SF00515
In collaboration with SLAC, LAPP and IFIC, a first prototype of a strip-line Beam Position Monitor (BPM) for the CLIC Drive Beam and its associated readout electronics has been successfully tested in the CLIC Test Facility linac (CTF3) at CERN. In addition, a modified prototype with downstream terminated strip-lines is under development to better suppress any unwanted RF signal interference. This paper presents the results of the beam tests, the most relevant design aspects for the modified strip-line BPM version and its expected performance.

Poster TUPC12 [1.729 MB]

TUPC28

Strip Line Monitor design for the ISIS Proton Synchrotron using the FEA program HFSS

coupling, kicker, feedback, scattering

435

S.J. Payne
STFC/RAL/ISIS, Chilton, Didcot, Oxon, United Kingdom

This paper reports the development of a strip line monitor for the ISIS accelerator main ring. The strip line is still in the design phase and the work reported here is the results of the FEA programme HFSS. The strip line will eventually form part of a beam instability feedback system and will be used to control instabilities both in the current ISIS machine and for all future ISIS upgrades where higher intensities and energies could be realised. The strip line consists of two pairs of 550mm by 160mm broad flat electrodes configured to allow damping in both the horizontal and vertical planes. The paper describes the efforts to achieve a bandwidth of >260MHz which will allow the feedback system deal with instabilities such as those caused by electron clouds. Design of the electrodes including matching of the feed throughs to the electrodes , concerns of materials for the electrode supports are considered. Also considered are methods used to improved inter-electrode decoupling (to better than -30db) . Results in the form of scattering parameters, smith charts, time domain reflectivity and shunt impedances will be presented.

WEPC17

Design and Simulation of Beam Position Monitor for the CADS Injector I Proton Linac

BPM, simulation, pick-up, linac

710

Y.F. Sui, J.S. Cao, H.Z. Ma, Q. Ye, J. Yue
IHEP, People's Republic of China

Funding: Work supported by the National Natural Science Foundation of China (NO. 11205172)
Beam Position Monitors (BPM) based on both capacitive and stripline pick-ups are designed for the China Accelerator Driven Subcritical system (C-ADS) Injector I proton LINAC. The BPM will be installed to measure the transverse beam position in the LINAC, of which the beam parameters are listed as current 10mA, energy 10MeV and the repetition frequency 325MHz. This contribution presents the status of the BPM design development and focuses on the design of the pick-ups and CST Particle Studio simulation results, including impedance, sensitivity, time domain, frequency domain response, etc. The main goal of the simulation is optimization of the mechanical design.

WEPC26

Pickup Electrode Electrodynamics Investigation

pick-up, LEFT, transverse, vacuum

742

A. Kalinin
STFC/DL/ASTeC, Daresbury, Warrington, Cheshire, United Kingdom

Waves induced in a pickup by beam were investigated on a large scale model, using 10ps step in coaxial line as beam, and a differentiating capacitive probe. The probe signal was observed at 20GHz oscilloscope. In each of the front and rear transverse gaps between pickup electrode and wall (button pickup), a shorter-than-gap bunch excites a ‘plain-wave’ packet which length is of the order of gap length over c. Two packets are spaced by electrode length over c. The packets propagate along the electrode to a coaxial connector. At this low impedance common point each of the packets partially reflects back and partially passes into the opposite gap. The voltage appearing on the impedance excites two TEM-wave packets: one propagates backwards, another one propagates forward through connector. The connector output is sum of two such packets spaced the same as two incident packets. The packets propagating backwards reflect from the electrode open end, come back to the summing point and generate output in similar way. The same processes occur in a pickup with single gap electrodes (stripline pickup). This phenomenological picture can be used as a guide in pickup design and simulation.

Poster WEPC26 [0.647 MB]

THBL1

RF Heating from Wake Losses in Diagnostics Structures

resonance, longitudinal, LHC, simulation

929

E. Métral
CERN, Geneva, Switzerland

Heating of diagnostics structures (striplines, buttons, screen vessels, wire scanners etc) has been observed at many facilities with higher stored currents*. Simulations of wake losses using 3D EM codes are regularly used to estimate the amount of power lost from the bunched beam but on its own this does not tell how much is radiated back into the beam pipe or transmitted into external ports and how much is actually being dissipated in the structure and where. This talk should introduce into the matter, summarise some of the observations at various facilities and illustrate what approaches of detailed simulations have been taken.
* summarizing a workshop at DLS (see http://tinyurl.com/wakeloss )

Slides THBL1 [9.078 MB]