IPAC2015 - List of Authors (Appleby, R.B.)

Paper	Title	Page
WEPWA043	Progress on the Design of the Racetrack FFAG Decay Ring for nuSTORM	2594
	J.-B. Lagrange, J. Pasternak Imperial College of Science and Technology, Department of Physics, London, United Kingdom R.B. Appleby, J.M. Garland, H.L. Owen, S.C. Tygier UMAN, Manchester, United Kingdom R.B. Appleby Cockcroft Institute, Warrington, Cheshire, United Kingdom Y. Mori Kyoto University, Research Reactor Institute, Osaka, Japan
	The neutrino beam produced from muons decaying in a storage ring would be an ideal tool for precise neutrino cross section measurements and search for sterile neutrinos due to its precisely known flavour content and spectrum. In the proposed nuSTORM facility pions would be directly injected into a storage ring, where circulating muon beam would be captured. The racetrack FFAG (Fixed Field Alternating Gradient) option for nuSTORM decay ring offers a very good performance due to a large dynamic and momentum acceptance. Machine parameters, linear optics design, beam dynamics and injection system for nuSTORM FFAG ring are discussed in this paper.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2015-WEPWA043
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MOPJE082	Analytical Approach to the Beam-Beam Interaction with the Hourglass Effect	510
	M.P. Crouch, R.B. Appleby UMAN, Manchester, United Kingdom B.D. Muratori STFC/DL/ASTeC, Daresbury, Warrington, Cheshire, United Kingdom
	Funding: STFC HL-LHC The HL-LHC upgrade will allow higher luminosities to be reached in the LHC. To achieve higher luminosities the β-function at the IP is decreased, which in turn will result in the hourglass effect becoming more prominent as the transverse bunch sizes become comparable to the length of the bunch. This effect reduces the luminosity since not all particles in the bunch will collide at the minimum IP. The standard derivation of the electric and magnetic fields of the beam-beam interaction is that undertaken by Bassetti and Erskine. The derivation by Bassetti Erskine does not include a coupling between bunch planes. When the transverse bunch sizes are comparable to the length of the bunch the magnitude of the transverse kick will be dependent on the longitudinal position. Currently only numerical methods are available to evaluate this effect. Here a theoretical framework is outlined that provides an analytical approach to derive the electric field for the beam-beam interaction with a coupling between the transverse and longitudinal planes.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2015-MOPJE082
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TUPTY069	Simulation of Hollow Electron Lenses as LHC Beam Halo Reducers using Merlin	2188
	H. Rafique, R.J. Barlow University of Huddersfield, Huddersfield, United Kingdom R.B. Appleby, S.C. Tygier UMAN, Manchester, United Kingdom R. Bruce, S. Redaelli CERN, Geneva, Switzerland
	Funding: Research supported by FP7 HiLumi LHC (Grant agreement 284404) The Large Hadron Collider (LHC) and its High Luminosity (HL) upgrade foresee unprecedented stored beam energies of up to 700 MJ. The collimation system is responsible for cleaning the beam halo and is vital for successful machine operation. Hollow electron lenses (HEL) are being considered for the LHC, based on Tevatron designs and operational experience, for active halo control. HELs can be used as soft scraper devices, and can operate close to the beam core without undergoing damage. We use the Merlin C++ accelerator libraries to implement a HEL and examine the effect on the beam halo for various test scenarios.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2015-TUPTY069
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TUPTY070	Strong-Strong Simulations of Beta star Levelling for Flat and Round Beams	2192
	M.P. Crouch, R.B. Appleby UMAN, Manchester, United Kingdom B.D. Muratori STFC/DL/ASTeC, Daresbury, Warrington, Cheshire, United Kingdom
	Funding: STFC HL-LHC The HL-LHC project aims to reach larger peak luminosities, however this can lead to a high pile up in the detectors. To control the pile up, luminosity levelling has been suggested. One proposed method is β-luminosity levelling, in which beams collide at a larger than nominal β. The β* is then reduced in steps as the beam intensity decays. This allows the luminosity to be kept constant over part of a physics fill. The use of round or flat optics will change the beam-beam effect of the head on collisions as well as the long range interactions. Here simulations of β* levelling are presented for the case of flat and round beam optics and the difference in terms of the beam-beam effect is highlighted.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2015-TUPTY070
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TUPWI021	Progress on a 30 - 350 MeV Normal-Conducting Scaling FFAG for Proton Therapy	2285
	J.M. Garland, R.B. Appleby, H.L. Owen, S.C. Tygier UMAN, Manchester, United Kingdom
	Funding: Work supported by the STFC (UK) under grant no. ST/K002503/1 We present our progress on a new design for a 30 - 350 MeV scaling FFAG for proton therapy and tomography - NORMA (NOrmal-conducting Racetrack Medical Accelerator) which allows the realisation of proton computed tomography (pCT) and utilises normal conducting magnets in both a circular and racetrack configuration which are designed using advanced optimisation algorithms developed in PyZgoubi. The ring and racetrack configurations have average circumferences of around 60 and 70 m respectively, peak magnetic fields of < 1.8 T, average orbit excursions < 50 cm and dynamic aperture calculations of > 50 mm.mrad using a novel technique. The racetrack design has a total magnet-free straight length of 4.9 m at two opposing points, designed to ease injection and extraction systems.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2015-TUPWI021
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WEPWA049	Low Energy Beam Tracking Under Scattering for a Cold Electron Source in Manchester	2615
	R.B. Appleby, W. Bertsche, Ö. Mete, G.X. Xia UMAN, Manchester, United Kingdom M.A. Harvey, M. Jones, A.J. Murray The University of Manchester, The Photon Science Institute, Manchester, United Kingdom B. Kyle University of Manchester, Manchester, United Kingdom
	High quality electron beams, with high spatial and temporal resolution, have an important use in electron diffraction experiments to probe and study the constituents of matter. A cold electron source is being developed based on electron ionisation from an atom cloud trapped by using AC magneto-optical methods in the University of Manchester. The technique will produce bunches of electrons well suited for high precision and single shot electron diffraction. In this paper issues of modelling at low energies for this state of art electron source with very low energy spread are presented, with a focus on newly developed tools to model the scattering in the meshes used to support the extraction electric fields. The dependence on emittance growth on mesh wire thickness is studied.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2015-WEPWA049
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Paper

Title

Page

Progress on the Design of the Racetrack FFAG Decay Ring for nuSTORM

2594

J.-B. Lagrange, J. Pasternak
Imperial College of Science and Technology, Department of Physics, London, United Kingdom
R.B. Appleby, J.M. Garland, H.L. Owen, S.C. Tygier
UMAN, Manchester, United Kingdom
R.B. Appleby
Cockcroft Institute, Warrington, Cheshire, United Kingdom
Y. Mori
Kyoto University, Research Reactor Institute, Osaka, Japan

The neutrino beam produced from muons decaying in a storage ring would be an ideal tool for precise neutrino cross section measurements and search for sterile neutrinos due to its precisely known flavour content and spectrum. In the proposed nuSTORM facility pions would be directly injected into a storage ring, where circulating muon beam would be captured. The racetrack FFAG (Fixed Field Alternating Gradient) option for nuSTORM decay ring offers a very good performance due to a large dynamic and momentum acceptance. Machine parameters, linear optics design, beam dynamics and injection system for nuSTORM FFAG ring are discussed in this paper.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2015-WEPWA043

Export •

reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

MOPJE082

Analytical Approach to the Beam-Beam Interaction with the Hourglass Effect

510

M.P. Crouch, R.B. Appleby
UMAN, Manchester, United Kingdom
B.D. Muratori
STFC/DL/ASTeC, Daresbury, Warrington, Cheshire, United Kingdom

Funding: STFC HL-LHC
The HL-LHC upgrade will allow higher luminosities to be reached in the LHC. To achieve higher luminosities the β-function at the IP is decreased, which in turn will result in the hourglass effect becoming more prominent as the transverse bunch sizes become comparable to the length of the bunch. This effect reduces the luminosity since not all particles in the bunch will collide at the minimum IP. The standard derivation of the electric and magnetic fields of the beam-beam interaction is that undertaken by Bassetti and Erskine. The derivation by Bassetti Erskine does not include a coupling between bunch planes. When the transverse bunch sizes are comparable to the length of the bunch the magnitude of the transverse kick will be dependent on the longitudinal position. Currently only numerical methods are available to evaluate this effect. Here a theoretical framework is outlined that provides an analytical approach to derive the electric field for the beam-beam interaction with a coupling between the transverse and longitudinal planes.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2015-MOPJE082

Export •

reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

TUPTY069

Simulation of Hollow Electron Lenses as LHC Beam Halo Reducers using Merlin

2188

H. Rafique, R.J. Barlow
University of Huddersfield, Huddersfield, United Kingdom
R.B. Appleby, S.C. Tygier
UMAN, Manchester, United Kingdom
R. Bruce, S. Redaelli
CERN, Geneva, Switzerland

Funding: Research supported by FP7 HiLumi LHC (Grant agreement 284404)
The Large Hadron Collider (LHC) and its High Luminosity (HL) upgrade foresee unprecedented stored beam energies of up to 700 MJ. The collimation system is responsible for cleaning the beam halo and is vital for successful machine operation. Hollow electron lenses (HEL) are being considered for the LHC, based on Tevatron designs and operational experience, for active halo control. HELs can be used as soft scraper devices, and can operate close to the beam core without undergoing damage. We use the Merlin C++ accelerator libraries to implement a HEL and examine the effect on the beam halo for various test scenarios.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2015-TUPTY069

Export •

reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

TUPTY070

Strong-Strong Simulations of Beta star Levelling for Flat and Round Beams

2192

M.P. Crouch, R.B. Appleby
UMAN, Manchester, United Kingdom
B.D. Muratori
STFC/DL/ASTeC, Daresbury, Warrington, Cheshire, United Kingdom

Funding: STFC HL-LHC
The HL-LHC project aims to reach larger peak luminosities, however this can lead to a high pile up in the detectors. To control the pile up, luminosity levelling has been suggested. One proposed method is β*-luminosity levelling, in which beams collide at a larger than nominal β*. The β* is then reduced in steps as the beam intensity decays. This allows the luminosity to be kept constant over part of a physics fill. The use of round or flat optics will change the beam-beam effect of the head on collisions as well as the long range interactions. Here simulations of β* levelling are presented for the case of flat and round beam optics and the difference in terms of the beam-beam effect is highlighted.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2015-TUPTY070

Export •

reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

TUPWI021

Progress on a 30 - 350 MeV Normal-Conducting Scaling FFAG for Proton Therapy

2285

J.M. Garland, R.B. Appleby, H.L. Owen, S.C. Tygier
UMAN, Manchester, United Kingdom

Funding: Work supported by the STFC (UK) under grant no. ST/K002503/1
We present our progress on a new design for a 30 - 350 MeV scaling FFAG for proton therapy and tomography - NORMA (NOrmal-conducting Racetrack Medical Accelerator) which allows the realisation of proton computed tomography (pCT) and utilises normal conducting magnets in both a circular and racetrack configuration which are designed using advanced optimisation algorithms developed in PyZgoubi. The ring and racetrack configurations have average circumferences of around 60 and 70 m respectively, peak magnetic fields of < 1.8 T, average orbit excursions < 50 cm and dynamic aperture calculations of > 50 mm.mrad using a novel technique. The racetrack design has a total magnet-free straight length of 4.9 m at two opposing points, designed to ease injection and extraction systems.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2015-TUPWI021

Export •

reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

WEPWA049

Low Energy Beam Tracking Under Scattering for a Cold Electron Source in Manchester

2615

R.B. Appleby, W. Bertsche, Ö. Mete, G.X. Xia
UMAN, Manchester, United Kingdom
M.A. Harvey, M. Jones, A.J. Murray
The University of Manchester, The Photon Science Institute, Manchester, United Kingdom
B. Kyle
University of Manchester, Manchester, United Kingdom

High quality electron beams, with high spatial and temporal resolution, have an important use in electron diffraction experiments to probe and study the constituents of matter. A cold electron source is being developed based on electron ionisation from an atom cloud trapped by using AC magneto-optical methods in the University of Manchester. The technique will produce bunches of electrons well suited for high precision and single shot electron diffraction. In this paper issues of modelling at low energies for this state of art electron source with very low energy spread are presented, with a focus on newly developed tools to model the scattering in the meshes used to support the extraction electric fields. The dependence on emittance growth on mesh wire thickness is studied.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2015-WEPWA049

Export •

reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)