IPAC2013 - List of Keywords (octupole)

Paper	Title	Other Keywords	Page
MOODB102	Multiple Function Magnet Systems for MAX IV	dipole, multipole, quadrupole, sextupole	34
	F. Bødker, C.E. Hansen, N. Hauge, E.K. Krauthammer, D. Kristoffersen, G. Nielsen, C.W.O. Ostenfeld, C.G. Pedersen Danfysik A/S, Taastrup, Denmark
	Danfysik is currently producing 60 up to 3.3 m long magnet systems consisting of up to 12 multipole magnets integrated into each of the yokes for the bending achromats of the MAX IV 3 GeV storage ring and 12 similar systems for the MAX IV 1.5 GeV storage ring. Each magnet yoke contains combined function soft-end dipole and quadrupole elements which are machined out of one single iron block at tolerances of ± 0.02 mm. In addition, separate, higher order multipole magnets are kinematically mounted into the yokes. The integration of many magnetic elements into single yoke structures enables a compact, low emittance storage ring design. The dipole and quadrupole magnetic elements are magnetically field mapped with high precision on a 3D hall probe measuring bench. Higher order multipoles are measured on a slow rotating coil system developed for that purpose. Much effort has been put into automation in order to quickly perform the very comprehensive measurement program each girder will through.
	Slides MOODB102 [2.701 MB]

MOPME076	Determination of Octupole and Sextupole Polarities in the LHC	sextupole, coupling, injection, lattice	655
	M.J. McAteer, Y.I. Levinsen, E.H. Maclean, T. Persson, P.K. Skowroński, R.J. Steinhagen, R. Tomás CERN, Geneva, Switzerland
	We report the results of measurements to verify the polarity of the LHC’s lattice focusing and defocusing octupoles (MOF and MOD), spool piece octupole correctors (MCO), arc skew sextupole correctors (MSS), and interaction region sextupoles (MCSX and MCSSX). Octupole polarities were determined by measuring the change to second order chromaticity when a magnet family was trimmed. The MSS skew sextupole corrector polarities were checked by measuring the change to chromatic coupling when a magnet family was trimmed. The polarities of the MCSSX skew sextupoles in IR 1 and the MCSX normal sextupoles in IR 5 were checked by measuring the tune shift due to a magnet trim. Comparison of measurements with model predictions indicates that the polarities of the octupoles and the IR sextupoles are correct, and the polarities of the MSS skew sextupole correctors are reversed.

TUPFI030	LHC Machine Developments in 2011-12	optics, luminosity, collimation, ion	1406
	G. Papotti, R.W. Aßmann, F. Zimmermann CERN, Geneva, Switzerland
	In 2011 and 2012 LHC machine development (MD) sessions were performed during dedicated slots of beam time. These MD studies were scheduled and planned well in advance. Study topics reflected the previously agreed priorities, such as further optimizing machine performance, exploring beam parameters beyond design targets, assessing machine limitations, testing new concepts and machine settings, preparing future LHC running in view of the 2013/14 LHC shutdown and the re-commissioning of the LHC at nominal beam energy in 2014/15. We describe the planning, preparation, execution, review, and documentation of these LHC beam studies and highlight some key results.

TUPFI032	Observation of Instabilities in the LHC due to Missing Head-on Beam-beam Interactions	damping, luminosity, beam-beam-effects, betatron	1412
	W. Herr, G. Arduini, R. Giachino, E. Métral, G. Papotti, T. Pieloni CERN, Geneva, Switzerland X. Buffat, N. Mounet EPFL, Lausanne, Switzerland
	We report the observation of coherent instabilities on individual bunches out of the LHC bunch train. These instabilities occured spontaneously after several hours of stable beam while in other cases they were related to the application of a small transverse beam separation during a luminosity optimization. Only few bunches were affected, depending on there collision scheme and following various tests we interprete these instabilities as a sudden loss of Landau damping when the tune spread from the beam-beam interaction became insufficient.

TUPFI034	Observations of Two-beam Instabilities during the 2012 LHC Physics Run	damping, betatron, impedance, luminosity	1418
	T. Pieloni EPFL, Lausanne, Switzerland G. Arduini, X. Buffat, R. Giachino, W. Herr, M. Lamont, N. Mounet, E. Métral, G. Papotti, B. Salvant, J. Wenninger CERN, Geneva, Switzerland S.M. White BNL, Upton, Long Island, New York, USA
	During the 2012 run coherent beam instabilities have been observed in the LHC at 4 TeV, during the betatron squeeze and in collision for special filling patterns. Several studies to characterize these instabilities have been carried out during operation and in special dedicated experiments. In this paper we summarize the observations collected for different machine parameters and the present understanding of the origin of these instabilities.

TUPFI035	Head-on and Long range Beam-beam Interactions in the LHC: Effective Tune Spread and Beam Stability due to Landau Damping	damping, luminosity, lattice, feedback	1421
	X. Buffat EPFL, Lausanne, Switzerland W. Herr, N. Mounet, E. Métral, T. Pieloni CERN, Geneva, Switzerland
	We discuss the Landau damping of coherent instabilities in the presence of betatron tune spread. This tune spread can originate from dedicated non-linear magnets such as octupoles, or through the beam-beam interaction. In the latter case we have to distinguish the contribution from head-on and parasitic beam-beam interactions and the collision pattern of different bunches plays an important role. The interplay of these sources of tune spread and the resulting stability is discussed for the case of the LHC.

TUPFI036	Observation of Beam Instabilities with Very Tight Collimation	damping, impedance, collimation, proton	1424
	H. Burkhardt, N. Mounet, T. Pieloni CERN, Geneva, Switzerland
	We report about the observation of instabilities in the LHC in special runs with high β^* and very tight collimation down to 2 σ which increases the transverse impedance significantly. The losses appeared primarily on the highest intensity, non-colliding bunches which can be interpreted as evidence for insufficient Landau damping. We describe the beam conditions, observations and possible explanations for the observed effects.

TUPFI039	Optics Performance of the LHC During the 2012 Run	coupling, optics, sextupole, quadrupole	1433
	P. Skowroński, T. Bach, M. Giovannozzi, A. Langner, Y.I. Levinsen, E.H. Maclean, T. Persson, S. Redaelli, T. Risselada, M. Solfaroli Camillocci, R. Tomás, G. Vanbavinckhove CERN, Geneva, Switzerland M.J. McAteer The University of Texas at Austin, Austin, USA R. Miyamoto ESS, Lund, Sweden T. Persson Chalmers University of Technology, Chalmers Tekniska Högskola, Gothenburg, Sweden
	During 2012 the LHC was operating at 4TeV with beta star at ATLAS and CMS interaction points of 0.6m. During dedicated machine studies the nominal LHC optics was also setup with beta star of 0.4m. A huge effort was put into the optics commissioning leading to a record low peak beta-beating of around 7%. We describe the correction procedures and discuss the measurement results.

TUPWO048	Understanding the Tune, Coupling, and Chromaticity Dependence of the LHC on Landau Octupole Powering	closed-orbit, coupling, alignment, simulation	1976
	E.H. Maclean, M. Giovannozzi, W. Herr, Y.I. Levinsen, G. Papotti, T. Persson, P.K. Skowroński, R. Tomás, J. Wenninger CERN, Geneva, Switzerland
	During the 2012 LHC run there were several observations of unexpectedly large shifts to the tune, chromaticity, and coupling which were correlated with changes in the powering of Landau octupoles (MO). Understanding the chromaticity dependence is of particular importance given it's influence on instabilities. This paper summarizes the observations and our attempts to-date to understand the relationship between Q, Q', c- and the MO powering.

WEPEA009	Effects of Field Imperfections in the Isochronous Mode of the CR Storage Ring at FAIR	dipole, quadrupole, sextupole, simulation	2510
	S.A. Litvinov, A. Dolinskyy, O.E. Gorda, M. Steck, H. Weick GSI, Darmstadt, Germany D. Toprek VINCA, Belgrade, Serbia
	Today the challenge is to measure masses of exotic nuclei up to the limits of nuclear existence which are characterized by low production cross-sections and short half-lives. The large acceptance Collector Ring (CR) at FAIR tuned in the isochronous ion-optical mode offers unique possibilities for such measurements. Nonlinear field errors as well as fringe fields of the wide aperture quadrupoles and dipoles strongly excite the high-order aberrations which negatively affect the time resolution of the isochronous ring. Their influence is investigated here and a possible correction scheme is shown.

WEPEA043	Working Point and Resonance Studies at the CERN PS	resonance, injection, controls, focusing	2597
	A. Huschauer, M. Benedikt, H. Damerau, P. Freyermuth, S.S. Gilardoni, R. Steerenberg, B. Vandorpe CERN, Geneva, Switzerland
	The increase of luminosity demanded by the High Luminosity LHC (HL-LHC) requires an increase of beam intensity, which might result in instabilities appearing at injection energy in the CERN PS. Transverse head-tail instabilities have already been observed on operational LHC beams and a stabilizing mechanism as an alternative to linear coupling is currently being studied. It consists of reducing the mode number of the transverse oscillation by changing linear chromaticity and in succession completely suppressing the instability by a transverse damper system with appropriate bandwidth. Therefore, a chromaticity correction scheme at low energy exploiting the intrinsic possibilities offered by special circuits mounted on top of the main magnet poles, the Pole Face Windings (PFW), has been examined. The presence of destructive betatron resonances, which restrict the choice of the injection working point and the maximum acceptable tune spread, forms an additional limitation for high-brightness and high-intensity beams in the CERN PS. To improve the current working point control scheme, the influence of the P F W on the machine resonances is presented in this paper.

WEPEA046	Experimental Observations from the LHC Dynamic Aperture Machine Development Study in 2012	dynamic-aperture, beam-losses, emittance, injection	2606
	M. Giovannozzi, S. Cettour Cave, R. De Maria, M. Ludwig, A. Macpherson, S. Redaelli, F. Roncarolo, M. Solfaroli Camillocci, W. Venturini Delsolaro CERN, Geneva, Switzerland
	In view of improving the understanding of the behaviour of the dynamic aperture and to benchmark the numerical simulations performed so far, two experimental sessions have been scheduled at the LHC. The observations of the first sessions have been reported elsewhere[1], while in this paper the latest observations in terms of beam currents, blm losses and beam sizes will be described. The octupolar spool pieces have been used to artificially reduce the dynamic aperture and then induced slow beam losses. Alternating signs have been used in order to probe different configurations. Finally, scans over the strength of the decapolar spool pieces have been performed too. [1] M. Giovannozzi et al., “First Experimental Observations from the LHC Dynamic Aperture Experiment”, in proceedings of IPAC12, p. 1362

THYB101	Suppressing Transverse Beam Halo with Nonlinear Magnetic Fields	lattice, resonance, space-charge, damping	3099
	S.D. Webb, D.T. Abell, D.L. Bruhwiler, J.R. Cary Tech-X, Boulder, Colorado, USA V.V. Danilov ORNL, Oak Ridge, Tennessee, USA S. Nagaitsev, A. Valishev Fermilab, Batavia, USA
	Funding: This work was supported in part by the US Department of Energy's Office of Science, Office of High Energy Physics, under grant No. DE-SC0006247. Traditional space charge driven resonances, such as beam halo, arise due to the underlying linear nature of accelerator lattices. In this talk, we present initial results on a new class of intrinsically nonlinear lattices, which introduce a large tune spread naturally. The resulting nonlinear decoherence suppresses the onset of beam halo.
	Slides THYB101 [63.510 MB]

THPME005	Status of the Super FRS Magnet Development for FAIR	dipole, quadrupole, status, sextupole	3519
	H. Müller, E.S. Fischer, H. Leibrock, P. Schnizer, M. Winkler GSI, Darmstadt, Germany
	The Super-FRS is a new two stage in flight separator to be built on the site of GSI, Darmstadt, Germany as part of the FAIR (Facility for Anti-proton and Ion Research). It will be able to create and spatially separate rare isotopes from all elements up to Uranium. Also very short lived nuclei will be observed efficiently. The Super-FRS has three branches, so a wide variety of experiments can be carried out in frame of the NUSTAR collaboration. The large acceptance needed leads to large apertures of the magnets and therefore only a superconducting solution is feasible. The magnets of the Super-FRS are of the so called superferric type. These magnets use superconducting coils but the field is shaped by magnetic iron yoke. In this contribution the actual status of the designs of the dipole and multipole magnets will be presented.

THPWA038	GEANT4 Studies of Magnets Activation in the HEBT Line for the European Spallation Source	proton, target, neutron, quadrupole	3714
	C. Bungau, R.J. Barlow, A. Bungau, R. Cywinski, T.R. Edgecock University of Huddersfield, Huddersfield, United Kingdom P. Carlsson, H. Danared, F. Mezei ESS, Lund, Sweden A.I.S. Holm, S.P. Møller, H.D. Thomsen ISA, Aarhus, Denmark
	The High Energy Beam Transport (HEBT) line for the European Spallation Source is designed to transport the beam from the underground linac to the target at the surface level while keeping the beam losses small and providing the requested beam footprint and profile on the target. This paper presents activation studies of the magnets in the HEBT line due to backscattered neutrons from the target and beam interactions inside the collimators producing unstable isotopes.

Paper

Title

Other Keywords

Page

MOODB102

Multiple Function Magnet Systems for MAX IV

dipole, multipole, quadrupole, sextupole

34

F. Bødker, C.E. Hansen, N. Hauge, E.K. Krauthammer, D. Kristoffersen, G. Nielsen, C.W.O. Ostenfeld, C.G. Pedersen
Danfysik A/S, Taastrup, Denmark

Danfysik is currently producing 60 up to 3.3 m long magnet systems consisting of up to 12 multipole magnets integrated into each of the yokes for the bending achromats of the MAX IV 3 GeV storage ring and 12 similar systems for the MAX IV 1.5 GeV storage ring. Each magnet yoke contains combined function soft-end dipole and quadrupole elements which are machined out of one single iron block at tolerances of ± 0.02 mm. In addition, separate, higher order multipole magnets are kinematically mounted into the yokes. The integration of many magnetic elements into single yoke structures enables a compact, low emittance storage ring design. The dipole and quadrupole magnetic elements are magnetically field mapped with high precision on a 3D hall probe measuring bench. Higher order multipoles are measured on a slow rotating coil system developed for that purpose. Much effort has been put into automation in order to quickly perform the very comprehensive measurement program each girder will through.

Slides MOODB102 [2.701 MB]

MOPME076

Determination of Octupole and Sextupole Polarities in the LHC

sextupole, coupling, injection, lattice

655

M.J. McAteer, Y.I. Levinsen, E.H. Maclean, T. Persson, P.K. Skowroński, R.J. Steinhagen, R. Tomás
CERN, Geneva, Switzerland

We report the results of measurements to verify the polarity of the LHC’s lattice focusing and defocusing octupoles (MOF and MOD), spool piece octupole correctors (MCO), arc skew sextupole correctors (MSS), and interaction region sextupoles (MCSX and MCSSX). Octupole polarities were determined by measuring the change to second order chromaticity when a magnet family was trimmed. The MSS skew sextupole corrector polarities were checked by measuring the change to chromatic coupling when a magnet family was trimmed. The polarities of the MCSSX skew sextupoles in IR 1 and the MCSX normal sextupoles in IR 5 were checked by measuring the tune shift due to a magnet trim. Comparison of measurements with model predictions indicates that the polarities of the octupoles and the IR sextupoles are correct, and the polarities of the MSS skew sextupole correctors are reversed.

TUPFI030

LHC Machine Developments in 2011-12

optics, luminosity, collimation, ion

1406

G. Papotti, R.W. Aßmann, F. Zimmermann
CERN, Geneva, Switzerland

In 2011 and 2012 LHC machine development (MD) sessions were performed during dedicated slots of beam time. These MD studies were scheduled and planned well in advance. Study topics reflected the previously agreed priorities, such as further optimizing machine performance, exploring beam parameters beyond design targets, assessing machine limitations, testing new concepts and machine settings, preparing future LHC running in view of the 2013/14 LHC shutdown and the re-commissioning of the LHC at nominal beam energy in 2014/15. We describe the planning, preparation, execution, review, and documentation of these LHC beam studies and highlight some key results.

TUPFI032

Observation of Instabilities in the LHC due to Missing Head-on Beam-beam Interactions

damping, luminosity, beam-beam-effects, betatron

1412

W. Herr, G. Arduini, R. Giachino, E. Métral, G. Papotti, T. Pieloni
CERN, Geneva, Switzerland
X. Buffat, N. Mounet
EPFL, Lausanne, Switzerland

We report the observation of coherent instabilities on individual bunches out of the LHC bunch train. These instabilities occured spontaneously after several hours of stable beam while in other cases they were related to the application of a small transverse beam separation during a luminosity optimization. Only few bunches were affected, depending on there collision scheme and following various tests we interprete these instabilities as a sudden loss of Landau damping when the tune spread from the beam-beam interaction became insufficient.

TUPFI034

Observations of Two-beam Instabilities during the 2012 LHC Physics Run

damping, betatron, impedance, luminosity

1418

T. Pieloni
EPFL, Lausanne, Switzerland
G. Arduini, X. Buffat, R. Giachino, W. Herr, M. Lamont, N. Mounet, E. Métral, G. Papotti, B. Salvant, J. Wenninger
CERN, Geneva, Switzerland
S.M. White
BNL, Upton, Long Island, New York, USA

During the 2012 run coherent beam instabilities have been observed in the LHC at 4 TeV, during the betatron squeeze and in collision for special filling patterns. Several studies to characterize these instabilities have been carried out during operation and in special dedicated experiments. In this paper we summarize the observations collected for different machine parameters and the present understanding of the origin of these instabilities.

TUPFI035

Head-on and Long range Beam-beam Interactions in the LHC: Effective Tune Spread and Beam Stability due to Landau Damping

damping, luminosity, lattice, feedback

1421

X. Buffat
EPFL, Lausanne, Switzerland
W. Herr, N. Mounet, E. Métral, T. Pieloni
CERN, Geneva, Switzerland

We discuss the Landau damping of coherent instabilities in the presence of betatron tune spread. This tune spread can originate from dedicated non-linear magnets such as octupoles, or through the beam-beam interaction. In the latter case we have to distinguish the contribution from head-on and parasitic beam-beam interactions and the collision pattern of different bunches plays an important role. The interplay of these sources of tune spread and the resulting stability is discussed for the case of the LHC.

TUPFI036

Observation of Beam Instabilities with Very Tight Collimation

damping, impedance, collimation, proton

1424

H. Burkhardt, N. Mounet, T. Pieloni
CERN, Geneva, Switzerland

We report about the observation of instabilities in the LHC in special runs with high β^* and very tight collimation down to 2 σ which increases the transverse impedance significantly. The losses appeared primarily on the highest intensity, non-colliding bunches which can be interpreted as evidence for insufficient Landau damping. We describe the beam conditions, observations and possible explanations for the observed effects.

TUPFI039

Optics Performance of the LHC During the 2012 Run

coupling, optics, sextupole, quadrupole

1433

P. Skowroński, T. Bach, M. Giovannozzi, A. Langner, Y.I. Levinsen, E.H. Maclean, T. Persson, S. Redaelli, T. Risselada, M. Solfaroli Camillocci, R. Tomás, G. Vanbavinckhove
CERN, Geneva, Switzerland
M.J. McAteer
The University of Texas at Austin, Austin, USA
R. Miyamoto
ESS, Lund, Sweden
T. Persson
Chalmers University of Technology, Chalmers Tekniska Högskola, Gothenburg, Sweden

During 2012 the LHC was operating at 4TeV with beta star at ATLAS and CMS interaction points of 0.6m. During dedicated machine studies the nominal LHC optics was also setup with beta star of 0.4m. A huge effort was put into the optics commissioning leading to a record low peak beta-beating of around 7%. We describe the correction procedures and discuss the measurement results.

TUPWO048

Understanding the Tune, Coupling, and Chromaticity Dependence of the LHC on Landau Octupole Powering

closed-orbit, coupling, alignment, simulation

1976

E.H. Maclean, M. Giovannozzi, W. Herr, Y.I. Levinsen, G. Papotti, T. Persson, P.K. Skowroński, R. Tomás, J. Wenninger
CERN, Geneva, Switzerland

During the 2012 LHC run there were several observations of unexpectedly large shifts to the tune, chromaticity, and coupling which were correlated with changes in the powering of Landau octupoles (MO). Understanding the chromaticity dependence is of particular importance given it's influence on instabilities. This paper summarizes the observations and our attempts to-date to understand the relationship between Q, Q', c- and the MO powering.

WEPEA009

Effects of Field Imperfections in the Isochronous Mode of the CR Storage Ring at FAIR

dipole, quadrupole, sextupole, simulation

2510

S.A. Litvinov, A. Dolinskyy, O.E. Gorda, M. Steck, H. Weick
GSI, Darmstadt, Germany
D. Toprek
VINCA, Belgrade, Serbia

Today the challenge is to measure masses of exotic nuclei up to the limits of nuclear existence which are characterized by low production cross-sections and short half-lives. The large acceptance Collector Ring (CR) at FAIR tuned in the isochronous ion-optical mode offers unique possibilities for such measurements. Nonlinear field errors as well as fringe fields of the wide aperture quadrupoles and dipoles strongly excite the high-order aberrations which negatively affect the time resolution of the isochronous ring. Their influence is investigated here and a possible correction scheme is shown.

WEPEA043

Working Point and Resonance Studies at the CERN PS

resonance, injection, controls, focusing

2597

A. Huschauer, M. Benedikt, H. Damerau, P. Freyermuth, S.S. Gilardoni, R. Steerenberg, B. Vandorpe
CERN, Geneva, Switzerland

The increase of luminosity demanded by the High Luminosity LHC (HL-LHC) requires an increase of beam intensity, which might result in instabilities appearing at injection energy in the CERN PS. Transverse head-tail instabilities have already been observed on operational LHC beams and a stabilizing mechanism as an alternative to linear coupling is currently being studied. It consists of reducing the mode number of the transverse oscillation by changing linear chromaticity and in succession completely suppressing the instability by a transverse damper system with appropriate bandwidth. Therefore, a chromaticity correction scheme at low energy exploiting the intrinsic possibilities offered by special circuits mounted on top of the main magnet poles, the Pole Face Windings (PFW), has been examined. The presence of destructive betatron resonances, which restrict the choice of the injection working point and the maximum acceptable tune spread, forms an additional limitation for high-brightness and high-intensity beams in the CERN PS. To improve the current working point control scheme, the influence of the P F W on the machine resonances is presented in this paper.

WEPEA046

Experimental Observations from the LHC Dynamic Aperture Machine Development Study in 2012

dynamic-aperture, beam-losses, emittance, injection

2606

M. Giovannozzi, S. Cettour Cave, R. De Maria, M. Ludwig, A. Macpherson, S. Redaelli, F. Roncarolo, M. Solfaroli Camillocci, W. Venturini Delsolaro
CERN, Geneva, Switzerland

In view of improving the understanding of the behaviour of the dynamic aperture and to benchmark the numerical simulations performed so far, two experimental sessions have been scheduled at the LHC. The observations of the first sessions have been reported elsewhere[1], while in this paper the latest observations in terms of beam currents, blm losses and beam sizes will be described. The octupolar spool pieces have been used to artificially reduce the dynamic aperture and then induced slow beam losses. Alternating signs have been used in order to probe different configurations. Finally, scans over the strength of the decapolar spool pieces have been performed too.
[1] M. Giovannozzi et al., “First Experimental Observations from the LHC Dynamic Aperture Experiment”, in proceedings of IPAC12, p. 1362

THYB101

Suppressing Transverse Beam Halo with Nonlinear Magnetic Fields

lattice, resonance, space-charge, damping

3099

S.D. Webb, D.T. Abell, D.L. Bruhwiler, J.R. Cary
Tech-X, Boulder, Colorado, USA
V.V. Danilov
ORNL, Oak Ridge, Tennessee, USA
S. Nagaitsev, A. Valishev
Fermilab, Batavia, USA

Funding: This work was supported in part by the US Department of Energy's Office of Science, Office of High Energy Physics, under grant No. DE-SC0006247.
Traditional space charge driven resonances, such as beam halo, arise due to the underlying linear nature of accelerator lattices. In this talk, we present initial results on a new class of intrinsically nonlinear lattices, which introduce a large tune spread naturally. The resulting nonlinear decoherence suppresses the onset of beam halo.

Slides THYB101 [63.510 MB]

THPME005

Status of the Super FRS Magnet Development for FAIR

dipole, quadrupole, status, sextupole

3519

H. Müller, E.S. Fischer, H. Leibrock, P. Schnizer, M. Winkler
GSI, Darmstadt, Germany

The Super-FRS is a new two stage in flight separator to be built on the site of GSI, Darmstadt, Germany as part of the FAIR (Facility for Anti-proton and Ion Research). It will be able to create and spatially separate rare isotopes from all elements up to Uranium. Also very short lived nuclei will be observed efficiently. The Super-FRS has three branches, so a wide variety of experiments can be carried out in frame of the NUSTAR collaboration. The large acceptance needed leads to large apertures of the magnets and therefore only a superconducting solution is feasible. The magnets of the Super-FRS are of the so called superferric type. These magnets use superconducting coils but the field is shaped by magnetic iron yoke. In this contribution the actual status of the designs of the dipole and multipole magnets will be presented.

THPWA038

GEANT4 Studies of Magnets Activation in the HEBT Line for the European Spallation Source

proton, target, neutron, quadrupole

3714

C. Bungau, R.J. Barlow, A. Bungau, R. Cywinski, T.R. Edgecock
University of Huddersfield, Huddersfield, United Kingdom
P. Carlsson, H. Danared, F. Mezei
ESS, Lund, Sweden
A.I.S. Holm, S.P. Møller, H.D. Thomsen
ISA, Aarhus, Denmark

The High Energy Beam Transport (HEBT) line for the European Spallation Source is designed to transport the beam from the underground linac to the target at the surface level while keeping the beam losses small and providing the requested beam footprint and profile on the target. This paper presents activation studies of the magnets in the HEBT line due to backscattered neutrons from the target and beam interactions inside the collimators producing unstable isotopes.