IPAC2021 - List of Authors (Lagrange, J.-B.)

Paper	Title	Page
TUPAB186	Longitudinal Dynamics in the Prototype vFFA Ring for ISIS2	1834
	D.J. Kelliher, J.-B. Lagrange, S. Machida, C.R. Prior, C.T. Rogers STFC/RAL/ISIS, Chilton, Didcot, Oxon, United Kingdom A.P. Letchford, J. Pasternak STFC/RAL, Chilton, Didcot, Oxon, United Kingdom J. Pasternak Imperial College of Science and Technology, Department of Physics, London, United Kingdom E. Yamakawa JAI, Egham, Surrey, United Kingdom
	A vertical Fixed Field Accelerator (vFFA) is a candidate for a future high-power (MW-class) spallation source at ISIS. In order to assess the feasibility of this novel ring, a prototype is currently being designed. Here we consider the longitudinal dynamics in the prototype ring. A key requirement of future neutron spallation sources is flexibility of operation to best serve multiple target stations. Beam stacking allows a rapid cycling, high intensity machine to operate at lower repetition rates but with higher peak output. Here we show how beam stacking can be realised in the vFFA while minimising the peak RF voltage required.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-TUPAB186
About •	paper received ※ 19 May 2021 paper accepted ※ 17 June 2021 issue date ※ 23 August 2021
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TUPAB208	FETS-FFA Ring Study	1901
	J.-B. Lagrange, D.J. Kelliher, A.P. Letchford, S. Machida, C.R. Prior, C.T. Rogers STFC/RAL/ISIS, Chilton, Didcot, Oxon, United Kingdom S.J. Brooks BNL, Upton, New York, USA C. Brown Brunel University, Middlesex, United Kingdom J. Pasternak STFC/RAL, Chilton, Didcot, Oxon, United Kingdom J. Pasternak Imperial College of Science and Technology, Department of Physics, London, United Kingdom E. Yamakawa JAI, Egham, Surrey, United Kingdom
	ISIS is the spallation neutron source at the Rutherford Appleton Laboratory in the UK, providing a proton beam with a power of 0.2~MW. Detailed studies are under way for a major upgrade, including the use of Fixed Field alternating gradient Accelerator (FFA). A proof-of-principle FFA ring, called FETS-FFA is planned to investigate the feasibility of this kind of machine for the required MW beam power. This paper discusses the study of the FETS-FFA ring case.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-TUPAB208
About •	paper received ※ 19 May 2021 paper accepted ※ 08 July 2021 issue date ※ 14 August 2021
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TUPAB209	The Particle Tracking Code Fixfield	1905
	J.-B. Lagrange STFC/RAL/ISIS, Chilton, Didcot, Oxon, United Kingdom
	FixField is a code developed to track particles in Fixed Field alternating gradient Accelerators (FFAs). This paper discusses the structure and features of the code.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-TUPAB209
About •	paper received ※ 19 May 2021 paper accepted ※ 02 July 2021 issue date ※ 25 August 2021
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THPAB124	Application of the FFA Concept to a Muon Collider Complex	4006
	S. Machida, J.-B. Lagrange STFC/RAL/ISIS, Chilton, Didcot, Oxon, United Kingdom M.E. Topp-Mugglestone JAI, Oxford, United Kingdom
	Muon collider complex is one of the places where the concept of fixed field alternating gradient (FFA) optics can be applied with great benefits. Vertical excursion FFA (vFFA) provides the isochronous condition for the ultra-relativistic muon beams after pre-acceleration. Together with the fixed transverse tune, it will be an ideal accelerator of short-lived muon beams with no time variation of magnetic fields and RF frequency. Novel collider ring optics is a design based on skew quadrupole after extracting essential functions from vFFA. That enables control of the momentum compaction factor. Neutrinos from the continuing decay of muons are spread out with orbit wiggling in the vertical direction as well as horizontal. The paper discusses the underline principle and describes some design examples.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-THPAB124
About •	paper received ※ 19 May 2021 paper accepted ※ 02 August 2021 issue date ※ 28 August 2021
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THPAB175	nuSTORM Accelerator Challenges and Opportunities	4104
	C.T. Rogers, J.-B. Lagrange STFC/RAL/ISIS, Chilton, Didcot, Oxon, United Kingdom N. Gall CERN, Meyrin, Switzerland J. Pasternak STFC/RAL, Chilton, Didcot, Oxon, United Kingdom J. Pasternak Imperial College of Science and Technology, Department of Physics, London, United Kingdom
	The nuSTORM facility uses a stored muon beam to generate a neutrino source. Muons are captured and stored in a storage ring using stochastic injection. The facility will aim to measure neutrino-nucleus scattering cross-sections with uniquely well-characterized neutrino beams; to facilitate the search for sterile neutrino and other Beyond Standard Model processes with exquisite sensitivity, and to provide a muon source that makes an excellent technology test-bed required for the development of muon beams capable of serving as a multi-TeV collider. In this paper, we describe the latest status of the development of nuSTORM, the R&D needs, and the potential for nuSTORM as a Muon Collider test facility.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-THPAB175
About •	paper received ※ 19 May 2021 paper accepted ※ 19 July 2021 issue date ※ 31 August 2021
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THPAB236	First Order Analytic Approaches to Modelling the Vertical Excursion Fixed Field Alternating Gradient Accelerator	4262
	M.E. Topp-Mugglestone, S.L. Sheehy JAI, Oxford, United Kingdom J.-B. Lagrange, S. Machida STFC/RAL/ISIS, Chilton, Didcot, Oxon, United Kingdom
	Whilst the Vertical Excursion Fixed Field Alternating Gradient Accelerator (VFFA) remains a promising solution to a number of problems at the frontiers of accelerator physics, the optics of this type of machine are still poorly understood. Current designers are forced to rely on brute-force numerical tracking codes, with optimisation dependent on time-consuming parameter scans. With an aim to both improve understanding of this machine, as well as to develop tools for rapid design and optimisation of VFFA lattices, first steps towards an analytic approach based on a linearised Hamiltonian formalism have been developed.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-THPAB236
About •	paper received ※ 13 May 2021 paper accepted ※ 14 July 2021 issue date ※ 10 August 2021
Export •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

Paper

Title

Page

Longitudinal Dynamics in the Prototype vFFA Ring for ISIS2

1834

D.J. Kelliher, J.-B. Lagrange, S. Machida, C.R. Prior, C.T. Rogers
STFC/RAL/ISIS, Chilton, Didcot, Oxon, United Kingdom
A.P. Letchford, J. Pasternak
STFC/RAL, Chilton, Didcot, Oxon, United Kingdom
J. Pasternak
Imperial College of Science and Technology, Department of Physics, London, United Kingdom
E. Yamakawa
JAI, Egham, Surrey, United Kingdom

A vertical Fixed Field Accelerator (vFFA) is a candidate for a future high-power (MW-class) spallation source at ISIS. In order to assess the feasibility of this novel ring, a prototype is currently being designed. Here we consider the longitudinal dynamics in the prototype ring. A key requirement of future neutron spallation sources is flexibility of operation to best serve multiple target stations. Beam stacking allows a rapid cycling, high intensity machine to operate at lower repetition rates but with higher peak output. Here we show how beam stacking can be realised in the vFFA while minimising the peak RF voltage required.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-TUPAB186

About •

paper received ※ 19 May 2021 paper accepted ※ 17 June 2021 issue date ※ 23 August 2021

Export •

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

TUPAB208

FETS-FFA Ring Study

1901

J.-B. Lagrange, D.J. Kelliher, A.P. Letchford, S. Machida, C.R. Prior, C.T. Rogers
STFC/RAL/ISIS, Chilton, Didcot, Oxon, United Kingdom
S.J. Brooks
BNL, Upton, New York, USA
C. Brown
Brunel University, Middlesex, United Kingdom
J. Pasternak
STFC/RAL, Chilton, Didcot, Oxon, United Kingdom
J. Pasternak
Imperial College of Science and Technology, Department of Physics, London, United Kingdom
E. Yamakawa
JAI, Egham, Surrey, United Kingdom

ISIS is the spallation neutron source at the Rutherford Appleton Laboratory in the UK, providing a proton beam with a power of 0.2~MW. Detailed studies are under way for a major upgrade, including the use of Fixed Field alternating gradient Accelerator (FFA). A proof-of-principle FFA ring, called FETS-FFA is planned to investigate the feasibility of this kind of machine for the required MW beam power. This paper discusses the study of the FETS-FFA ring case.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-TUPAB208

About •

paper received ※ 19 May 2021 paper accepted ※ 08 July 2021 issue date ※ 14 August 2021

Export •

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

TUPAB209

The Particle Tracking Code Fixfield

1905

J.-B. Lagrange
STFC/RAL/ISIS, Chilton, Didcot, Oxon, United Kingdom

FixField is a code developed to track particles in Fixed Field alternating gradient Accelerators (FFAs). This paper discusses the structure and features of the code.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-TUPAB209

About •

paper received ※ 19 May 2021 paper accepted ※ 02 July 2021 issue date ※ 25 August 2021

Export •

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

THPAB124

Application of the FFA Concept to a Muon Collider Complex

4006

S. Machida, J.-B. Lagrange
STFC/RAL/ISIS, Chilton, Didcot, Oxon, United Kingdom
M.E. Topp-Mugglestone
JAI, Oxford, United Kingdom

Muon collider complex is one of the places where the concept of fixed field alternating gradient (FFA) optics can be applied with great benefits. Vertical excursion FFA (vFFA) provides the isochronous condition for the ultra-relativistic muon beams after pre-acceleration. Together with the fixed transverse tune, it will be an ideal accelerator of short-lived muon beams with no time variation of magnetic fields and RF frequency. Novel collider ring optics is a design based on skew quadrupole after extracting essential functions from vFFA. That enables control of the momentum compaction factor. Neutrinos from the continuing decay of muons are spread out with orbit wiggling in the vertical direction as well as horizontal. The paper discusses the underline principle and describes some design examples.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-THPAB124

About •

paper received ※ 19 May 2021 paper accepted ※ 02 August 2021 issue date ※ 28 August 2021

Export •

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

THPAB175

nuSTORM Accelerator Challenges and Opportunities

4104

C.T. Rogers, J.-B. Lagrange
STFC/RAL/ISIS, Chilton, Didcot, Oxon, United Kingdom
N. Gall
CERN, Meyrin, Switzerland
J. Pasternak
STFC/RAL, Chilton, Didcot, Oxon, United Kingdom
J. Pasternak
Imperial College of Science and Technology, Department of Physics, London, United Kingdom

The nuSTORM facility uses a stored muon beam to generate a neutrino source. Muons are captured and stored in a storage ring using stochastic injection. The facility will aim to measure neutrino-nucleus scattering cross-sections with uniquely well-characterized neutrino beams; to facilitate the search for sterile neutrino and other Beyond Standard Model processes with exquisite sensitivity, and to provide a muon source that makes an excellent technology test-bed required for the development of muon beams capable of serving as a multi-TeV collider. In this paper, we describe the latest status of the development of nuSTORM, the R&D needs, and the potential for nuSTORM as a Muon Collider test facility.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-THPAB175

About •

paper received ※ 19 May 2021 paper accepted ※ 19 July 2021 issue date ※ 31 August 2021

Export •

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

THPAB236

First Order Analytic Approaches to Modelling the Vertical Excursion Fixed Field Alternating Gradient Accelerator

4262

M.E. Topp-Mugglestone, S.L. Sheehy
JAI, Oxford, United Kingdom
J.-B. Lagrange, S. Machida
STFC/RAL/ISIS, Chilton, Didcot, Oxon, United Kingdom

Whilst the Vertical Excursion Fixed Field Alternating Gradient Accelerator (VFFA) remains a promising solution to a number of problems at the frontiers of accelerator physics, the optics of this type of machine are still poorly understood. Current designers are forced to rely on brute-force numerical tracking codes, with optimisation dependent on time-consuming parameter scans. With an aim to both improve understanding of this machine, as well as to develop tools for rapid design and optimisation of VFFA lattices, first steps towards an analytic approach based on a linearised Hamiltonian formalism have been developed.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-THPAB236

About •

paper received ※ 13 May 2021 paper accepted ※ 14 July 2021 issue date ※ 10 August 2021

Export •

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