2011 Particle Accelerator Conference - List of Keywords (multipole)

Paper	Title	Other Keywords	Page
MOP104	Simulation Studies of the Dielectric Grating as an Accelerating and Focusing Structure	focusing, simulation, laser, alignment	292
	K. Soong, E.R. Colby SLAC, Menlo Park, California, USA R.L. Byer, E.A. Peralta Stanford University, Stanford, California, USA
	Funding: Work funded by DOE contract DE‐AC02‐76SF00515 (SLAC) A grating-based design is a promising candidate for a laser-driven dielectric accelerator. Through simulations, we show the merits of a readily fabricated grating structure as an accelerating component. Additionally, we show that with a small design perturbation, the accelerating component can be converted into a focusing structure. The understanding of these two components is critical in the successful development of any complete accelerator.

MOP192	NSLS-II BPM System Protection from Rogue Mode Coupling	shielding, vacuum, radiation, synchrotron	450
	A. Blednykh, B. Bacha, A. Borrelli, M.J. Ferreira, C. Hetzel, H.-C. Hseuh, B.N. Kosciuk, S. Krinsky, O. Singh, K. Vetter BNL, Upton, Long Island, New York, USA
	Funding: Work supported by DOE contract DE-AC02-98CH10886 Rogue mode RF shielding has been successfully designed and implemented into the production multipole vacuum chambers. In order to avoid systematic errors in the NSLS-II BPM system we introduced frequency shift of HOM's by using RF metal shielding located in the antechamber slot of each multipole vacuum chamber. To satisfy the pumping requirement the face of the shielding has been perforated with roughly 50 percent transparency. It stays clear of synchrotron radiation in each chamber.

TUOCN1	Accurate Computation of Transfer Maps for Realistic Beamline Elements from Surface Data	wiggler, dipole, electron, damping	742
	C.E. Mitchell NRL, Washington, DC, USA A. Dragt UMD, College Park, Maryland, USA
	The behavior of orbits in charged-particle beam transport systems, including both linear and circular accelerators as well as final focus sections and spectrometers, can depend sensitively on nonlinear fringe-field and high-order-multipole effects in the various beam-line elements. The inclusion of these effects requires a detailed and realistic model of the interior and fringe fields, including their high spatial derivatives. A collection of surface fitting methods has been developed for extracting this information accurately from 3-dimensional field data on a grid, as provided by various 3-dimensional finite-element field codes. Based on these realistic field models, Lie or other methods may be used to compute accurate design orbits and accurate transfer maps about these orbits. This talk will provide a description of the methods along with example applications. An exactly-soluble but numerically challenging model field is used to provide a rigorous collection of performance benchmarks.
	Slides TUOCN1 [1.630 MB]

TUP104	Nb3Sn Block-coil Dipole for High-field Substitution in the LHC Lattice	dipole, lattice, insertion, superconductivity	1033
	A. Sattarov, E.F. Holik, A.D. McInturff, P.M. McIntyre Texas A&M University, College Station, Texas, USA
	Funding: This work was supported in part by the U.S. Department of Energy under Grant DE-FG02-06ER41405 A design is being developed to prototype for a dipole for this purpose: a block-coil dipole with 13 T short- sample field, 11 T working field, and 6 cm aperture. The dipole is a natural application of the high-field dipole strategy developed at Texas A&M, using simple pancake windings, flux-plate suppression of low-field multipoles, and bladder preloading. A short model dipole is planned.

TUP174	Warm Magnetic Field Measurements of LARP HQ Magnet	quadrupole, dipole, luminosity, alignment	1154
	X. Wang, S. Caspi, D.W. Cheng, D.R. Dietderich, H. Felice, P. Ferracin, R.R. Hafalia, J.M. Joseph, J. Lizarazo, M. Martchevskii, C. Nash, G.L. Sabbi, C. Vu LBNL, Berkeley, California, USA G. Ambrosio, R. Bossert, G. Chlachidze, J. DiMarco, V. Kashikhin Fermilab, Batavia, USA J. Schmalzle, P. Wanderer BNL, Upton, Long Island, New York, USA
	The US-LHC Accelerator Research Program is develop- ing and testing a high-gradient quadrupole (HQ) magnet, aiming at demonstrating the feasibility of Nb3Sn technologies for the LHC luminosity upgrade. The 1 m long HQ magnet has a 120 mm bore with a conductor-limited gradient of 219 T/m at 1.9 K and a peak field of 15 T. HQ includes accelerator features such as alignment and field quality. Here we present the magnetic measurement results obtained at LBNL with a constant current of 30 A. A 100 mm long circuit-board rotating coil developed by FNAL was used and the induced voltage and flux increment were acquired. The measured b6 ranges from 0.3 to 0.5 units in the magnet straight section at a reference radius of 21.55 mm. The data reduced from the numerical integration of the raw voltage agree with those from the fast digital integrators.

TUP227	Status of NSLS-II Storage Ring Vacuum Systems	vacuum, photon, dipole, radiation	1244
	H.-C. Hseuh, A. Blednykh, L. Doom, M.J. Ferreira, C. Hetzel, J. Hu, S. Leng, C. Longo, V. Ravindranath, K. Roy, S.K. Sharma, F.J. Willeke, K. Wilson, D. Zigrosser BNL, Upton, Long Island, New York, USA
	Funding: Work performed under the auspices of U.S. Department of Energy, under contract DE-AC02-98CH10886 National Synchrotron Light Source II (NSLS-II), being constructed at Brookhaven National Laboratory, is a 3- GeV, high-flux and high-brightness synchrotron radiation facility with a nominal current of 500 mA. The storage ring vacuum system has extruded aluminium chambers, with ante-chamber for photon fans and distributed NEG strip pumping. Discrete photon absorbers are used to intercept the un-used bending magnet radiation. In-situ bakeout is implemented to achieve fast conditioning during initial commissioning and after interventions.

TUP235	Strategy for Neutralizing the Impact of Insertion Devices on the MAX IV 3 GeV Ring	storage-ring, optics, lattice, vacuum	1262
	E.J. Wallén, S.C. Leemann MAX-lab, Lund, Sweden
	In order to prepare for the potentially negative influence on the beam lifetime, injection efficiency and beam size from the insertion devices (IDs) on the stored beam of the MAX IV 3 GeV storage ring strategy for neutralizing the foreseen effects of the IDs has been developed. In short the strategy involves a local correction of the betatron phase advance by adjusting the strength of the quadrupoles adjacent to the ID. There will also be a global tune correction in order to avoid drift in the working point of the storage ring during operation. Air coils with empirical feed forward tables for the excitation current in the coils will compensate for field integral errors. The lattice of the MAX IV 3 GeV storage ring appears to be robust and it tolerates the dynamic multipoles created by the expected initial set of IDs provided that the local correction of the betatron phase advance has been carried out.

WEOCS2	Development of Nb3Sn 11 T Single Aperture Demonstrator Dipole for LHC Upgrades	dipole, collimation, magnet-design, injection	1460
	A.V. Zlobin, N. Andreev, G. Apollinari, E.Z. Barzi, V. Kashikhin, A. Nobrega, I. Novitski Fermilab, Batavia, USA B. Auchmann, M. Karppinen, L. Rossi CERN, Geneva, Switzerland
	Funding: Work is supported by Fermi Research Alliance, LLC, under contract No. DE-AC02-07CH11359 with the U.S. Department of Energy The LHC collimation upgrade foresees additional collimators installed in dispersion suppressor regions. To obtain the necessary space for the collimators, a solution based on the substitution of LHC main dipoles for stronger dipoles is being considered. CERN and FNAL have started a joint program to demonstrate the feasibility of Nb3Sn technology for this purpose. The goal of the first phase is the design and construction of a 2-m long single-aperture demonstrator magnet with a nominal field of 11 T at 11.85 kA with 20% margin. This paper describes the magnetic and mechanical design of the demonstrator magnet and summarizes its design parameters.
	Slides WEOCS2 [2.523 MB]

WEP017	Re-Examination of the NSLS-II Magnet Multipole Specifications	sextupole, quadrupole, magnet-design, lattice	1531
	W. Guo, A.K. Jain, S. Krinsky, S. Seiler, J. Skaritka, C.J. Spataro BNL, Upton, Long Island, New York, USA
	Funding: Work supported by Brookhaven Science Associates, LLC under Contract No. DE-AC02-98CH10886 with the U.S. Department of Energy The NSLS-II magnet multipole specifications were determined based on analysis of nonlinear beam dynamics. The required field quality does not exceed what was specified for the existing third-generation light sources. While the prototype magnets have met these specifications, the magnets from mass production could potentially have bigger errors which exceed certain tolerances. In this paper we discuss the results of recent calculations to provide further insight into the acceptable range of the magnet multipoles based on the physics requirements.

WEP070	Ring for Test of Nonlinear Integrable Optics	betatron, lattice, optics, quadrupole	1606
	A. Valishev, V.S. Kashikhin, S. Nagaitsev Fermilab, Batavia, USA V.V. Danilov ORNL, Oak Ridge, Tennessee, USA
	Funding: Work supported by UT-Battelle, LLC and by FRA, LLC for the U. S. DOE under contracts No. DE-AC05-00OR22725 and DE-AC02-07CH11359 respectively. Nonlinear optics is a promising idea potentially opening the path towards achieving super high beam intensities in circular accelerators. Creation of a tune spread reaching 50% of the betatron tune would provide strong Landau damping and make the beam immune to instabilities. Recent theoretical work* have identified a possible way to implement stable nonlinear optics by incorporating nonlinear focusing elements into a specially designed machine lattice. In this report we propose the design of a test accelerator for a proof-of-principle experiment. We discuss possible studies at the machine, requirements on the optics stability and sensitivity to imperfections. * V. Danilov and S. Nagaitsev, Phys. Rev. ST Accel. Beams 13, 084002 (2010)

WEP141	Development of a Stepwise Ray-Tracing Based on-Line Model at AGS	dipole, lattice, closed-orbit, quadrupole	1749
	F. Méot, L. A. Ahrens, K.A. Brown, J.W. Glenn, H. Huang, T. Roser, V. Schoefer, N. Tsoupas BNL, Upton, Long Island, New York, USA
	Funding: Work supported by Brookhaven Science Associates, LLC under Contract No. DE-AC02-98CH10886 with the U.S. Department of Energy. A model of the Alternating Gradient Synchrotron is being developed based on stepwise ray-tracing numerical tools. It provides a realistic representation of the lattice, and accounts for the two helical partial Siberian snake insertions. The aim is to make this stepwise ray-tracing based model an aid for the understanding of the AGS, in matter of both beam dynamics and polarization transmission.

WEP157	An Implementation of the Fast Multipole Method for High Accuracy Particle Tracking of Intense Beams	space-charge, simulation, hadron, brightness	1782
	E.W. Nissen, B. Erdelyi Northern Illinois University, DeKalb, Illinois, USA
	We implement a single level version of the fast multipole method in the software package COSY Infinity. This algorithm has been used in other physics fields to determine high accuracy electrostatic potentials, and is implemented here for charged particle beams. The method scales like NlogN with the particle number and has a priori error estimates, which can be reduced to essentially machine precision if multipole expansions of high enough order are employed, resulting in a highly accurate algorithm for simulation of intense beams without averaging such as encountered in PIC methods. In order to further speed up the algorithm we use COSY Infinity’s innate differential algebraic methods to help with the expansions inherent in this system. Differential algebras allow for fast and exact numerical differentiation of functions that carries through any mathematical transformations performed, and can be used to quickly create the expansions used in the fast multipole method. This can then be combined with moment method techniques to extract transfer maps which include space charge within distributions that are difficult to approximate.

THP214	Pulsed Multipole Injection for the MAX IV Storage Rings	injection, storage-ring, septum, sextupole	2522
	S.C. Leemann MAX-lab, Lund, Sweden
	The MAX IV facility presently under construction will include two storage rings for the production of synchrotron radiation. The 3 GeV ring will house insertion devices for the production for x-rays while the 1.5 GeV ring will serve UV and IR users. Both rings will be operated at a constant 500 mA of stored current with top-up shots supplied by the 3.5 GeV MAX IV linac acting as a full-energy injector. So far, injection into both storage rings has been designed using a conventional approach: a closed four-kicker injection bump brings the stored beam to the septum blade where the injected bunches are captured in a single turn. Recently, studies have been carried out to investigate the feasibility of using a pulsed multipole for injection into the storage rings. Pulsed multipole injection does not require an injection bump and has the potential to make top-up injection transparent to users. This paper reports on these studies and summarizes requirements for the pulsed sextupole magnet to be installed for injection into the MAX IV storage rings.

Paper

Title

Other Keywords

Page

MOP104

Simulation Studies of the Dielectric Grating as an Accelerating and Focusing Structure

focusing, simulation, laser, alignment

292

K. Soong, E.R. Colby
SLAC, Menlo Park, California, USA
R.L. Byer, E.A. Peralta
Stanford University, Stanford, California, USA

Funding: Work funded by DOE contract DE‐AC02‐76SF00515 (SLAC)
A grating-based design is a promising candidate for a laser-driven dielectric accelerator. Through simulations, we show the merits of a readily fabricated grating structure as an accelerating component. Additionally, we show that with a small design perturbation, the accelerating component can be converted into a focusing structure. The understanding of these two components is critical in the successful development of any complete accelerator.

MOP192

NSLS-II BPM System Protection from Rogue Mode Coupling

shielding, vacuum, radiation, synchrotron

450

A. Blednykh, B. Bacha, A. Borrelli, M.J. Ferreira, C. Hetzel, H.-C. Hseuh, B.N. Kosciuk, S. Krinsky, O. Singh, K. Vetter
BNL, Upton, Long Island, New York, USA

Funding: Work supported by DOE contract DE-AC02-98CH10886
Rogue mode RF shielding has been successfully designed and implemented into the production multipole vacuum chambers. In order to avoid systematic errors in the NSLS-II BPM system we introduced frequency shift of HOM's by using RF metal shielding located in the antechamber slot of each multipole vacuum chamber. To satisfy the pumping requirement the face of the shielding has been perforated with roughly 50 percent transparency. It stays clear of synchrotron radiation in each chamber.

TUOCN1

Accurate Computation of Transfer Maps for Realistic Beamline Elements from Surface Data

wiggler, dipole, electron, damping

742

C.E. Mitchell
NRL, Washington, DC, USA
A. Dragt
UMD, College Park, Maryland, USA

The behavior of orbits in charged-particle beam transport systems, including both linear and circular accelerators as well as final focus sections and spectrometers, can depend sensitively on nonlinear fringe-field and high-order-multipole effects in the various beam-line elements. The inclusion of these effects requires a detailed and realistic model of the interior and fringe fields, including their high spatial derivatives. A collection of surface fitting methods has been developed for extracting this information accurately from 3-dimensional field data on a grid, as provided by various 3-dimensional finite-element field codes. Based on these realistic field models, Lie or other methods may be used to compute accurate design orbits and accurate transfer maps about these orbits. This talk will provide a description of the methods along with example applications. An exactly-soluble but numerically challenging model field is used to provide a rigorous collection of performance benchmarks.

Slides TUOCN1 [1.630 MB]

TUP104

Nb3Sn Block-coil Dipole for High-field Substitution in the LHC Lattice

dipole, lattice, insertion, superconductivity

1033

A. Sattarov, E.F. Holik, A.D. McInturff, P.M. McIntyre
Texas A&M University, College Station, Texas, USA

Funding: This work was supported in part by the U.S. Department of Energy under Grant DE-FG02-06ER41405
A design is being developed to prototype for a dipole for this purpose: a block-coil dipole with 13 T short- sample field, 11 T working field, and 6 cm aperture. The dipole is a natural application of the high-field dipole strategy developed at Texas A&M, using simple pancake windings, flux-plate suppression of low-field multipoles, and bladder preloading. A short model dipole is planned.

TUP174

Warm Magnetic Field Measurements of LARP HQ Magnet

quadrupole, dipole, luminosity, alignment

1154

X. Wang, S. Caspi, D.W. Cheng, D.R. Dietderich, H. Felice, P. Ferracin, R.R. Hafalia, J.M. Joseph, J. Lizarazo, M. Martchevskii, C. Nash, G.L. Sabbi, C. Vu
LBNL, Berkeley, California, USA
G. Ambrosio, R. Bossert, G. Chlachidze, J. DiMarco, V. Kashikhin
Fermilab, Batavia, USA
J. Schmalzle, P. Wanderer
BNL, Upton, Long Island, New York, USA

The US-LHC Accelerator Research Program is develop- ing and testing a high-gradient quadrupole (HQ) magnet, aiming at demonstrating the feasibility of Nb3Sn technologies for the LHC luminosity upgrade. The 1 m long HQ magnet has a 120 mm bore with a conductor-limited gradient of 219 T/m at 1.9 K and a peak field of 15 T. HQ includes accelerator features such as alignment and field quality. Here we present the magnetic measurement results obtained at LBNL with a constant current of 30 A. A 100 mm long circuit-board rotating coil developed by FNAL was used and the induced voltage and flux increment were acquired. The measured b6 ranges from 0.3 to 0.5 units in the magnet straight section at a reference radius of 21.55 mm. The data reduced from the numerical integration of the raw voltage agree with those from the fast digital integrators.

TUP227

Status of NSLS-II Storage Ring Vacuum Systems

vacuum, photon, dipole, radiation

1244

H.-C. Hseuh, A. Blednykh, L. Doom, M.J. Ferreira, C. Hetzel, J. Hu, S. Leng, C. Longo, V. Ravindranath, K. Roy, S.K. Sharma, F.J. Willeke, K. Wilson, D. Zigrosser
BNL, Upton, Long Island, New York, USA

Funding: Work performed under the auspices of U.S. Department of Energy, under contract DE-AC02-98CH10886
National Synchrotron Light Source II (NSLS-II), being constructed at Brookhaven National Laboratory, is a 3- GeV, high-flux and high-brightness synchrotron radiation facility with a nominal current of 500 mA. The storage ring vacuum system has extruded aluminium chambers, with ante-chamber for photon fans and distributed NEG strip pumping. Discrete photon absorbers are used to intercept the un-used bending magnet radiation. In-situ bakeout is implemented to achieve fast conditioning during initial commissioning and after interventions.

TUP235

Strategy for Neutralizing the Impact of Insertion Devices on the MAX IV 3 GeV Ring

storage-ring, optics, lattice, vacuum

1262

E.J. Wallén, S.C. Leemann
MAX-lab, Lund, Sweden

In order to prepare for the potentially negative influence on the beam lifetime, injection efficiency and beam size from the insertion devices (IDs) on the stored beam of the MAX IV 3 GeV storage ring strategy for neutralizing the foreseen effects of the IDs has been developed. In short the strategy involves a local correction of the betatron phase advance by adjusting the strength of the quadrupoles adjacent to the ID. There will also be a global tune correction in order to avoid drift in the working point of the storage ring during operation. Air coils with empirical feed forward tables for the excitation current in the coils will compensate for field integral errors. The lattice of the MAX IV 3 GeV storage ring appears to be robust and it tolerates the dynamic multipoles created by the expected initial set of IDs provided that the local correction of the betatron phase advance has been carried out.

WEOCS2

Development of Nb3Sn 11 T Single Aperture Demonstrator Dipole for LHC Upgrades

dipole, collimation, magnet-design, injection

1460

A.V. Zlobin, N. Andreev, G. Apollinari, E.Z. Barzi, V. Kashikhin, A. Nobrega, I. Novitski
Fermilab, Batavia, USA
B. Auchmann, M. Karppinen, L. Rossi
CERN, Geneva, Switzerland

Funding: Work is supported by Fermi Research Alliance, LLC, under contract No. DE-AC02-07CH11359 with the U.S. Department of Energy
The LHC collimation upgrade foresees additional collimators installed in dispersion suppressor regions. To obtain the necessary space for the collimators, a solution based on the substitution of LHC main dipoles for stronger dipoles is being considered. CERN and FNAL have started a joint program to demonstrate the feasibility of Nb3Sn technology for this purpose. The goal of the first phase is the design and construction of a 2-m long single-aperture demonstrator magnet with a nominal field of 11 T at 11.85 kA with 20% margin. This paper describes the magnetic and mechanical design of the demonstrator magnet and summarizes its design parameters.

Slides WEOCS2 [2.523 MB]

WEP017

Re-Examination of the NSLS-II Magnet Multipole Specifications

sextupole, quadrupole, magnet-design, lattice

1531

W. Guo, A.K. Jain, S. Krinsky, S. Seiler, J. Skaritka, C.J. Spataro
BNL, Upton, Long Island, New York, USA

Funding: Work supported by Brookhaven Science Associates, LLC under Contract No. DE-AC02-98CH10886 with the U.S. Department of Energy
The NSLS-II magnet multipole specifications were determined based on analysis of nonlinear beam dynamics. The required field quality does not exceed what was specified for the existing third-generation light sources. While the prototype magnets have met these specifications, the magnets from mass production could potentially have bigger errors which exceed certain tolerances. In this paper we discuss the results of recent calculations to provide further insight into the acceptable range of the magnet multipoles based on the physics requirements.

WEP070

Ring for Test of Nonlinear Integrable Optics

betatron, lattice, optics, quadrupole

1606

A. Valishev, V.S. Kashikhin, S. Nagaitsev
Fermilab, Batavia, USA
V.V. Danilov
ORNL, Oak Ridge, Tennessee, USA

Funding: Work supported by UT-Battelle, LLC and by FRA, LLC for the U. S. DOE under contracts No. DE-AC05-00OR22725 and DE-AC02-07CH11359 respectively.
Nonlinear optics is a promising idea potentially opening the path towards achieving super high beam intensities in circular accelerators. Creation of a tune spread reaching 50% of the betatron tune would provide strong Landau damping and make the beam immune to instabilities. Recent theoretical work* have identified a possible way to implement stable nonlinear optics by incorporating nonlinear focusing elements into a specially designed machine lattice. In this report we propose the design of a test accelerator for a proof-of-principle experiment. We discuss possible studies at the machine, requirements on the optics stability and sensitivity to imperfections.
* V. Danilov and S. Nagaitsev, Phys. Rev. ST Accel. Beams 13, 084002 (2010)

WEP141

Development of a Stepwise Ray-Tracing Based on-Line Model at AGS

dipole, lattice, closed-orbit, quadrupole

1749

F. Méot, L. A. Ahrens, K.A. Brown, J.W. Glenn, H. Huang, T. Roser, V. Schoefer, N. Tsoupas
BNL, Upton, Long Island, New York, USA

Funding: Work supported by Brookhaven Science Associates, LLC under Contract No. DE-AC02-98CH10886 with the U.S. Department of Energy.
A model of the Alternating Gradient Synchrotron is being developed based on stepwise ray-tracing numerical tools. It provides a realistic representation of the lattice, and accounts for the two helical partial Siberian snake insertions. The aim is to make this stepwise ray-tracing based model an aid for the understanding of the AGS, in matter of both beam dynamics and polarization transmission.

WEP157

An Implementation of the Fast Multipole Method for High Accuracy Particle Tracking of Intense Beams

space-charge, simulation, hadron, brightness

1782

E.W. Nissen, B. Erdelyi
Northern Illinois University, DeKalb, Illinois, USA

We implement a single level version of the fast multipole method in the software package COSY Infinity. This algorithm has been used in other physics fields to determine high accuracy electrostatic potentials, and is implemented here for charged particle beams. The method scales like NlogN with the particle number and has a priori error estimates, which can be reduced to essentially machine precision if multipole expansions of high enough order are employed, resulting in a highly accurate algorithm for simulation of intense beams without averaging such as encountered in PIC methods. In order to further speed up the algorithm we use COSY Infinity’s innate differential algebraic methods to help with the expansions inherent in this system. Differential algebras allow for fast and exact numerical differentiation of functions that carries through any mathematical transformations performed, and can be used to quickly create the expansions used in the fast multipole method. This can then be combined with moment method techniques to extract transfer maps which include space charge within distributions that are difficult to approximate.

THP214

Pulsed Multipole Injection for the MAX IV Storage Rings

injection, storage-ring, septum, sextupole

2522

S.C. Leemann
MAX-lab, Lund, Sweden

The MAX IV facility presently under construction will include two storage rings for the production of synchrotron radiation. The 3 GeV ring will house insertion devices for the production for x-rays while the 1.5 GeV ring will serve UV and IR users. Both rings will be operated at a constant 500 mA of stored current with top-up shots supplied by the 3.5 GeV MAX IV linac acting as a full-energy injector. So far, injection into both storage rings has been designed using a conventional approach: a closed four-kicker injection bump brings the stored beam to the septum blade where the injected bunches are captured in a single turn. Recently, studies have been carried out to investigate the feasibility of using a pulsed multipole for injection into the storage rings. Pulsed multipole injection does not require an injection bump and has the potential to make top-up injection transparent to users. This paper reports on these studies and summarizes requirements for the pulsed sextupole magnet to be installed for injection into the MAX IV storage rings.