IPAC2012 - List of Authors (Kelliher, D.J.)

Paper

Title

Page

Status of the PRISM FFAG Design for the Next Generation Muon-to-Electron Conversion Experiment

79

J. Pasternak, A. Alekou, M. Aslaninejad, R. Chudzinski, L.J. Jenner, A. Kurup, Y. Shi, Y. Uchida
Imperial College of Science and Technology, Department of Physics, London, United Kingdom
R. Appleby, H.L. Owen
UMAN, Manchester, United Kingdom
R.J. Barlow
University of Huddersfield, Huddersfield, United Kingdom
K.M. Hock, B.D. Muratori
Cockcroft Institute, Warrington, Cheshire, United Kingdom
D.J. Kelliher, S. Machida, C.R. Prior
STFC/RAL/ASTeC, Chilton, Didcot, Oxon, United Kingdom
Y. Kuno, A. Sato
Osaka University, Osaka, Japan
J.-B. Lagrange, Y. Mori
Kyoto University, Research Reactor Institute, Osaka, Japan
M. Lancaster
UCL, London, United Kingdom
C. Ohmori
KEK, Tokai, Ibaraki, Japan
T. Planche
TRIUMF, Canada's National Laboratory for Particle and Nuclear Physics, Vancouver, Canada
S.L. Smith
STFC/DL/ASTeC, Daresbury, Warrington, Cheshire, United Kingdom
H. Witte
BNL, Upton, Long Island, New York, USA
T. Yokoi
JAI, Oxford, United Kingdom

The PRISM Task Force continues to study high intensity and high quality muon beams needed for next generation lepton flavor violation experiments. In the PRISM case such beams have been proposed to be produced by sending a short proton pulse to a pion production target, capturing the pions and performing RF phase rotation on the resulting muon beam in an FFAG ring. This paper summarizes the current status of the PRISM design obtained by the Task Force. In particular various designs for the PRISM FFAG ring are discussed and their performance compared to the baseline one, the injection/extraction systems and matching to the solenoid channels upstream and downstream of the FFAG ring are presented. The feasibility of the construction of the PRISM system is discussed.

MOPPC030

Status of the Decay Ring Design for the IDS Neutrino Factory

199

D.J. Kelliher, C.R. Prior
STFC/RAL/ASTeC, Chilton, Didcot, Oxon, United Kingdom
N. Bliss, N.A. Collomb
STFC/DL, Daresbury, Warrington, Cheshire, United Kingdom
J. Pasternak
STFC/RAL, Chilton, Didcot, Oxon, United Kingdom

In the International Design Study for the Neutrino Factory (IDS-NF) a racetrack design has been adopted for the decay ring*. The injection system into the decay ring is described. The feasibility of injecting both positive and negative muons into the ring is explored from the point of view of injection timing. Considerations for the design of a decay ring for a 10 GeV neutrino factory are included.
* ”International Design Study for the Neutrino Factory – interim design report”, RAL-TR-2011-018 (2011)

MOPPC049

Status of the Non-scaling Fixed Field Alternating Gradient Ring Design for the International Design Study of the Neutrino Factory

241

J.S. Berg, H. Witte
BNL, Upton, Long Island, New York, USA
M. Aslaninejad, J. Pasternak
Imperial College of Science and Technology, Department of Physics, London, United Kingdom
N. Bliss, A.J. Moss
STFC/DL, Daresbury, Warrington, Cheshire, United Kingdom
D.J. Kelliher, S. Machida
STFC/RAL/ASTeC, Chilton, Didcot, Oxon, United Kingdom
S.M. Pattalwar
STFC/DL/ASTeC, Daresbury, Warrington, Cheshire, United Kingdom

Funding: This manuscript has been authored by employees of Brookhaven Science Associates, LLC under Contract No. DE-AC02-98CH10886 with the U.S. Department of Energy.
The International Design Study of the Neutrino Factory is working towards delivering the optimized design of the neutrino factory facility to be presented in the Reference Design Report (RDR) in 2013. In the current baseline design a linear non-scaling fixed field alternating gradient accelerator (FFAG) was chosen as an efficient solution for the final muon acceleration. We describe updates to the design since our previous report*. We report on beam dynamics studies on the lattice. We describe recent work on the engineering for the lattice, and the results of a recent first pass at a cost estimate for the machine. Finally, we describe how an FFAG may be applicable to a lower energy neutrino factory in light of recent experimental results regarding the value of the theta(13) neutrino mixing angle**.
* J. S. Berg et al., in Proceedings of IPAC2011, San Sebastian, Spain, 832.
** F. P. An et al., Phys. Rev. Lett. 10⁸, 171803 (2012); J. K. Ahn et al., arXiv:1204.0626v2 [hep-ex] (2012).

MOPPD020

A Model for a High-Power Scaling FFAG Ring

409

G.H. Rees, D.J. Kelliher, S. Machida, C.R. Prior, S.L. Sheehy
STFC/RAL/ASTeC, Chilton, Didcot, Oxon, United Kingdom

High-power FFAG rings are under study to serve as drivers for neutron spallation, muon production, and accelerator-driven reactor systems. In this paper, which follows on from earlier work*, a 20 - 70 MeV model for a high-power FFAG driver is described. This model would serve as a test bed to study topics such as space charge and injection in such rings. The design incorporates a long straight to facilitate H^- charge exchange injection. The dynamic aperture is calculated in order to optimize the working point in tune space. The injection scheme is also described. A separate design for an ISIS injector, featuring a novel modification to the scaling law, was also studied.
*G.H. Rees and D.J. Kelliher, “New, high power, scaling, FFAG driver ring designs” HB2010, Morschach, September 2010, MOPD07, p. 54, http://www. JACoW.org

MOPPD021

An Experimental Investigation of Slow Integer Tune Crossing in the EMMA Non-scaling FFAG

412

J.M. Garland, H.L. Owen
UMAN, Manchester, United Kingdom
D.J. Kelliher, S. Machida
STFC/RAL/ASTeC, Chilton, Didcot, Oxon, United Kingdom
B.D. Muratori
STFC/DL/ASTeC, Daresbury, Warrington, Cheshire, United Kingdom

Funding: Student STFC grant number: ST/G004277/1.
Results are presented from a slow integer tune crossing experiment performed in the EMMA accelerator. Under nominal conditions EMMA accelerates an electron beam from 10–20 MeV rapidly in 5–10 turns in a novel “serpentine” channel causing several transverse integer tunes to be crossed. During this rapid acceleration it has been shown that the betatron amplitude of the beam does not grow. If the potential of non-scaling FFAGs were to be realized in such fields as high-current proton acceleration then tune space would be crossed slower with acceleration in an RF bucket. The crossing speed in a non-scaling FFAG is in a previously unstudied intermediate region and hence conventional crossing theory may not apply. It was proposed to observe the effects on betatron amplitude when a beam crosses integer tunes by the variation of tune with momentum over a range of crossing speeds derived from different acceleration rates. This method can be realized by synchrotron acceleration inside a stable RF bucket. Betatron amplitude growth and beam loss as a function of turn are explored when crossing an integer tune and a relationship between crossing speed and these quantities is established.

MOPPR060

Calibration of the EMMA Beam Position Monitors: Position, Charge and Accuracy

921

I.W. Kirkman
The University of Liverpool, Liverpool, United Kingdom
J.S. Berg
BNL, Upton, Long Island, New York, USA
G. Cox
STFC/DL, Daresbury, Warrington, Cheshire, United Kingdom
A. Kalinin
STFC/DL/ASTeC, Daresbury, Warrington, Cheshire, United Kingdom
D.J. Kelliher, S. Machida
STFC/RAL/ASTeC, Chilton, Didcot, Oxon, United Kingdom

The accurate determination of transverse beam position is essential to understanding the performance of an accelerator system, and this is particularly the case with non-scaling FFAG machines such as EMMA, where, due to fundamental principles of design, the beam may deviate widely from the central beampipe axis. This paper describes the various modelling approaches taken for the three different button pickup assemblies used in EMMA, and the subsequent methods of calibration (‘mappings’) which allow beam position and charge to be deduced from the processed BPM signals. The use and validity of the modelling and mapping approach adopted is described, and the contributions to positional and bunch charge uncertainty arising from these procedures is discussed.

MOPPR061

Computing Bunch Charge, Position, and BPM Resolution in Turn-by-Turn EMMA BPMs

924

A. Kalinin, J.K. Jones
STFC/DL/ASTeC, Daresbury, Warrington, Cheshire, United Kingdom
R.G. Borrell
WareWorks Ltd, Manchester, United Kingdom
G. Cox
STFC/DL, Daresbury, Warrington, Cheshire, United Kingdom
D.J. Kelliher, S. Machida
STFC/RAL/ASTeC, Chilton, Didcot, Oxon, United Kingdom
I.W. Kirkman
Cockcroft Institute, Warrington, Cheshire, United Kingdom

The NS-FFAG electron model ‘EMMA’ and its Injection and Extraction Lines are equipped with a total of 53 EPICS VME BPMs*. In the BPMs, each opposite button signal pair is time-domain-multiplexed into one channel as a pulse doublet. The recording of turn-by-turn data into the BPM memory is triggered by the bunch itself on each of its passages. For each accelerating cycle, the BPMs deliver a snapshot of a turn-by-turn trajectory measured in each of 42 cells. Additional BPMs (two pairs) are used to obtain a Poincare map. We describe the EPICS architecture, and a set of Python data processing algorithms that are used to automatically set a BPM intensity range, to eliminate an error due to tails of the doublet pulses, to calculate the bunch charge and position, and, for a set of injections, to find the BPM resolution. We use three types of button pickup mappings** that allow: to eliminate bunch charge signal dependence on offset, to get a linear offset response, and to eliminate ‘quadrupole’ signal dependence on offset as well (which is used in resolution calculation). We present beam measurement results collected in 2011 runs.
* A. Kalinin et al., Proc. of IPAC’10, MOPE068, p. 1134, (2010.
** I. Kirkman, these proceedings.

TUPPD021

Orbit Correction in the EMMA Non-scaling FFAG – Simulation and Experimental Results

1455

D.J. Kelliher, S. Machida, S.L. Sheehy
STFC/RAL/ASTeC, Chilton, Didcot, Oxon, United Kingdom
J.S. Berg
BNL, Upton, Long Island, New York, USA
J.K. Jones, B.D. Muratori
STFC/DL/ASTeC, Daresbury, Warrington, Cheshire, United Kingdom
E. Keil
Honorary CERN Staff Member, Berlin, Germany
I.W. Kirkman
The University of Liverpool, Liverpool, United Kingdom

The non-scaling FFAG EMMA (Electron Model for Many Applications) is currently in operation at Daresbury Laboratory, UK. Since the lattice is made up solely of linear elements, the betatron tune varies strongly over the momentum range according to the natural chromaticity. Orbit correction is complicated by the resulting variation in response to corrector magnet settings. We consider a method to optimise correction over a range of fixed momenta and discuss experimental results. Measurements of the closed orbit and response matrix are included.

WEOAB01

New Results from the EMMA Experiment

2134

B.D. Muratori, J.K. Jones
STFC/DL/ASTeC, Daresbury, Warrington, Cheshire, United Kingdom
C.S. Edmonds, K.M. Hock, M.G. Ibison, I.W. Kirkman
The University of Liverpool, Liverpool, United Kingdom
J.M. Garland, H.L. Owen
UMAN, Manchester, United Kingdom
D.J. Kelliher, S. Machida
STFC/RAL/ASTeC, Chilton, Didcot, Oxon, United Kingdom
J. Pasternak
Imperial College of Science and Technology, Department of Physics, London, United Kingdom

EMMA (Electron Model for Many Applications) is a prototype non-scaling electron FFAG hosted at Daresbury Laboratory. After demonstration of acceleration in the serpentine channel in April 2011, the beam study with EMMA continues to explore the large transverse and longitudinal acceptance and effects of integer tune crossing with slower rate on the betatron amplitude. Together with a comparison of detailed models based on measured field maps and the experimental mapping of the machine by relating the initial and final phase space coordinates. These recent results together with more practical improvements such as injection orbit matching with real-time monitoring of the coordinates in the transverse phase space will be reported in this paper.

Slides WEOAB01 [2.120 MB]

Paper	Title	Page
MOEPPB003	Status of the PRISM FFAG Design for the Next Generation Muon-to-Electron Conversion Experiment	79
	J. Pasternak, A. Alekou, M. Aslaninejad, R. Chudzinski, L.J. Jenner, A. Kurup, Y. Shi, Y. Uchida Imperial College of Science and Technology, Department of Physics, London, United Kingdom R. Appleby, H.L. Owen UMAN, Manchester, United Kingdom R.J. Barlow University of Huddersfield, Huddersfield, United Kingdom K.M. Hock, B.D. Muratori Cockcroft Institute, Warrington, Cheshire, United Kingdom D.J. Kelliher, S. Machida, C.R. Prior STFC/RAL/ASTeC, Chilton, Didcot, Oxon, United Kingdom Y. Kuno, A. Sato Osaka University, Osaka, Japan J.-B. Lagrange, Y. Mori Kyoto University, Research Reactor Institute, Osaka, Japan M. Lancaster UCL, London, United Kingdom C. Ohmori KEK, Tokai, Ibaraki, Japan T. Planche TRIUMF, Canada's National Laboratory for Particle and Nuclear Physics, Vancouver, Canada S.L. Smith STFC/DL/ASTeC, Daresbury, Warrington, Cheshire, United Kingdom H. Witte BNL, Upton, Long Island, New York, USA T. Yokoi JAI, Oxford, United Kingdom
	The PRISM Task Force continues to study high intensity and high quality muon beams needed for next generation lepton flavor violation experiments. In the PRISM case such beams have been proposed to be produced by sending a short proton pulse to a pion production target, capturing the pions and performing RF phase rotation on the resulting muon beam in an FFAG ring. This paper summarizes the current status of the PRISM design obtained by the Task Force. In particular various designs for the PRISM FFAG ring are discussed and their performance compared to the baseline one, the injection/extraction systems and matching to the solenoid channels upstream and downstream of the FFAG ring are presented. The feasibility of the construction of the PRISM system is discussed.

MOPPC030	Status of the Decay Ring Design for the IDS Neutrino Factory	199
	D.J. Kelliher, C.R. Prior STFC/RAL/ASTeC, Chilton, Didcot, Oxon, United Kingdom N. Bliss, N.A. Collomb STFC/DL, Daresbury, Warrington, Cheshire, United Kingdom J. Pasternak STFC/RAL, Chilton, Didcot, Oxon, United Kingdom
	In the International Design Study for the Neutrino Factory (IDS-NF) a racetrack design has been adopted for the decay ring. The injection system into the decay ring is described. The feasibility of injecting both positive and negative muons into the ring is explored from the point of view of injection timing. Considerations for the design of a decay ring for a 10 GeV neutrino factory are included. ”International Design Study for the Neutrino Factory – interim design report”, RAL-TR-2011-018 (2011)

MOPPC049	Status of the Non-scaling Fixed Field Alternating Gradient Ring Design for the International Design Study of the Neutrino Factory	241
	J.S. Berg, H. Witte BNL, Upton, Long Island, New York, USA M. Aslaninejad, J. Pasternak Imperial College of Science and Technology, Department of Physics, London, United Kingdom N. Bliss, A.J. Moss STFC/DL, Daresbury, Warrington, Cheshire, United Kingdom D.J. Kelliher, S. Machida STFC/RAL/ASTeC, Chilton, Didcot, Oxon, United Kingdom S.M. Pattalwar STFC/DL/ASTeC, Daresbury, Warrington, Cheshire, United Kingdom
	Funding: This manuscript has been authored by employees of Brookhaven Science Associates, LLC under Contract No. DE-AC02-98CH10886 with the U.S. Department of Energy. The International Design Study of the Neutrino Factory is working towards delivering the optimized design of the neutrino factory facility to be presented in the Reference Design Report (RDR) in 2013. In the current baseline design a linear non-scaling fixed field alternating gradient accelerator (FFAG) was chosen as an efficient solution for the final muon acceleration. We describe updates to the design since our previous report. We report on beam dynamics studies on the lattice. We describe recent work on the engineering for the lattice, and the results of a recent first pass at a cost estimate for the machine. Finally, we describe how an FFAG may be applicable to a lower energy neutrino factory in light of recent experimental results regarding the value of the theta(13) neutrino mixing angle. J. S. Berg et al., in Proceedings of IPAC2011, San Sebastian, Spain, 832. ** F. P. An et al., Phys. Rev. Lett. 10⁸, 171803 (2012); J. K. Ahn et al., arXiv:1204.0626v2 [hep-ex] (2012).

MOPPD020	A Model for a High-Power Scaling FFAG Ring	409
	G.H. Rees, D.J. Kelliher, S. Machida, C.R. Prior, S.L. Sheehy STFC/RAL/ASTeC, Chilton, Didcot, Oxon, United Kingdom
	High-power FFAG rings are under study to serve as drivers for neutron spallation, muon production, and accelerator-driven reactor systems. In this paper, which follows on from earlier work, a 20 - 70 MeV model for a high-power FFAG driver is described. This model would serve as a test bed to study topics such as space charge and injection in such rings. The design incorporates a long straight to facilitate H^- charge exchange injection. The dynamic aperture is calculated in order to optimize the working point in tune space. The injection scheme is also described. A separate design for an ISIS injector, featuring a novel modification to the scaling law, was also studied. G.H. Rees and D.J. Kelliher, “New, high power, scaling, FFAG driver ring designs” HB2010, Morschach, September 2010, MOPD07, p. 54, http://www. JACoW.org

MOPPD021	An Experimental Investigation of Slow Integer Tune Crossing in the EMMA Non-scaling FFAG	412
	J.M. Garland, H.L. Owen UMAN, Manchester, United Kingdom D.J. Kelliher, S. Machida STFC/RAL/ASTeC, Chilton, Didcot, Oxon, United Kingdom B.D. Muratori STFC/DL/ASTeC, Daresbury, Warrington, Cheshire, United Kingdom
	Funding: Student STFC grant number: ST/G004277/1. Results are presented from a slow integer tune crossing experiment performed in the EMMA accelerator. Under nominal conditions EMMA accelerates an electron beam from 10–20 MeV rapidly in 5–10 turns in a novel “serpentine” channel causing several transverse integer tunes to be crossed. During this rapid acceleration it has been shown that the betatron amplitude of the beam does not grow. If the potential of non-scaling FFAGs were to be realized in such fields as high-current proton acceleration then tune space would be crossed slower with acceleration in an RF bucket. The crossing speed in a non-scaling FFAG is in a previously unstudied intermediate region and hence conventional crossing theory may not apply. It was proposed to observe the effects on betatron amplitude when a beam crosses integer tunes by the variation of tune with momentum over a range of crossing speeds derived from different acceleration rates. This method can be realized by synchrotron acceleration inside a stable RF bucket. Betatron amplitude growth and beam loss as a function of turn are explored when crossing an integer tune and a relationship between crossing speed and these quantities is established.

MOPPR060	Calibration of the EMMA Beam Position Monitors: Position, Charge and Accuracy	921
	I.W. Kirkman The University of Liverpool, Liverpool, United Kingdom J.S. Berg BNL, Upton, Long Island, New York, USA G. Cox STFC/DL, Daresbury, Warrington, Cheshire, United Kingdom A. Kalinin STFC/DL/ASTeC, Daresbury, Warrington, Cheshire, United Kingdom D.J. Kelliher, S. Machida STFC/RAL/ASTeC, Chilton, Didcot, Oxon, United Kingdom
	The accurate determination of transverse beam position is essential to understanding the performance of an accelerator system, and this is particularly the case with non-scaling FFAG machines such as EMMA, where, due to fundamental principles of design, the beam may deviate widely from the central beampipe axis. This paper describes the various modelling approaches taken for the three different button pickup assemblies used in EMMA, and the subsequent methods of calibration (‘mappings’) which allow beam position and charge to be deduced from the processed BPM signals. The use and validity of the modelling and mapping approach adopted is described, and the contributions to positional and bunch charge uncertainty arising from these procedures is discussed.

MOPPR061	Computing Bunch Charge, Position, and BPM Resolution in Turn-by-Turn EMMA BPMs	924
	A. Kalinin, J.K. Jones STFC/DL/ASTeC, Daresbury, Warrington, Cheshire, United Kingdom R.G. Borrell WareWorks Ltd, Manchester, United Kingdom G. Cox STFC/DL, Daresbury, Warrington, Cheshire, United Kingdom D.J. Kelliher, S. Machida STFC/RAL/ASTeC, Chilton, Didcot, Oxon, United Kingdom I.W. Kirkman Cockcroft Institute, Warrington, Cheshire, United Kingdom
	The NS-FFAG electron model ‘EMMA’ and its Injection and Extraction Lines are equipped with a total of 53 EPICS VME BPMs. In the BPMs, each opposite button signal pair is time-domain-multiplexed into one channel as a pulse doublet. The recording of turn-by-turn data into the BPM memory is triggered by the bunch itself on each of its passages. For each accelerating cycle, the BPMs deliver a snapshot of a turn-by-turn trajectory measured in each of 42 cells. Additional BPMs (two pairs) are used to obtain a Poincare map. We describe the EPICS architecture, and a set of Python data processing algorithms that are used to automatically set a BPM intensity range, to eliminate an error due to tails of the doublet pulses, to calculate the bunch charge and position, and, for a set of injections, to find the BPM resolution. We use three types of button pickup mappings* that allow: to eliminate bunch charge signal dependence on offset, to get a linear offset response, and to eliminate ‘quadrupole’ signal dependence on offset as well (which is used in resolution calculation). We present beam measurement results collected in 2011 runs. * A. Kalinin et al., Proc. of IPAC’10, MOPE068, p. 1134, (2010. ** I. Kirkman, these proceedings.

TUPPD021	Orbit Correction in the EMMA Non-scaling FFAG – Simulation and Experimental Results	1455
	D.J. Kelliher, S. Machida, S.L. Sheehy STFC/RAL/ASTeC, Chilton, Didcot, Oxon, United Kingdom J.S. Berg BNL, Upton, Long Island, New York, USA J.K. Jones, B.D. Muratori STFC/DL/ASTeC, Daresbury, Warrington, Cheshire, United Kingdom E. Keil Honorary CERN Staff Member, Berlin, Germany I.W. Kirkman The University of Liverpool, Liverpool, United Kingdom
	The non-scaling FFAG EMMA (Electron Model for Many Applications) is currently in operation at Daresbury Laboratory, UK. Since the lattice is made up solely of linear elements, the betatron tune varies strongly over the momentum range according to the natural chromaticity. Orbit correction is complicated by the resulting variation in response to corrector magnet settings. We consider a method to optimise correction over a range of fixed momenta and discuss experimental results. Measurements of the closed orbit and response matrix are included.

WEOAB01	New Results from the EMMA Experiment	2134
	B.D. Muratori, J.K. Jones STFC/DL/ASTeC, Daresbury, Warrington, Cheshire, United Kingdom C.S. Edmonds, K.M. Hock, M.G. Ibison, I.W. Kirkman The University of Liverpool, Liverpool, United Kingdom J.M. Garland, H.L. Owen UMAN, Manchester, United Kingdom D.J. Kelliher, S. Machida STFC/RAL/ASTeC, Chilton, Didcot, Oxon, United Kingdom J. Pasternak Imperial College of Science and Technology, Department of Physics, London, United Kingdom
	EMMA (Electron Model for Many Applications) is a prototype non-scaling electron FFAG hosted at Daresbury Laboratory. After demonstration of acceleration in the serpentine channel in April 2011, the beam study with EMMA continues to explore the large transverse and longitudinal acceptance and effects of integer tune crossing with slower rate on the betatron amplitude. Together with a comparison of detailed models based on measured field maps and the experimental mapping of the machine by relating the initial and final phase space coordinates. These recent results together with more practical improvements such as injection orbit matching with real-time monitoring of the coordinates in the transverse phase space will be reported in this paper.
	Slides WEOAB01 [2.120 MB]