2011 Particle Accelerator Conference - List of Authors (Neuffer, D.V.)

Paper	Title	Page
MOP030	Muon Capture for the Front End of a μ+μ- Collider	157
	D.V. Neuffer Fermilab, Batavia, USA C. Y. Yoshikawa Muons, Inc, Batavia, USA
	We discuss the design of the muon capture front end for a μ±μ- Collider. In the front end, a proton bunch on a target creates secondary pions that drift into a capture transport channel, decaying into muons. A sequence of rf cavities forms the resulting muon beams into strings of bunches of differing energies, aligns the bunches to (nearly) equal central energies, and initiates ionization cooling. The muons are then cooled and accelerated to high energy into a storage ring for high-energy high luminosity collisions. Our initial design is based on the somewhat similar front end of the International Design Study (IDS) neutrino factory.

MOP047	Helical Channels with Variable Slip Factor for Neutrino Factories and Muon Colliders	187
	C. Y. Yoshikawa, C.M. Ankenbrandt Muons, Inc, Batavia, USA D.V. Neuffer, K. Yonehara Fermilab, Batavia, USA
	Funding: Supported in part by DOE SBIR grant DE-SC0002739. In order to realize a muon collider or a neutrino factory based on a muon storage ring, the muons must be captured and cooled efficiently. For a muon collider, the resulting train of bunches should be coalesced into a single bunch. Design concepts for a system to capture, cool, and coalesce a muon beam are described here. In particular, variants of a helical channel are used, taking advantage of the ability to vary the slip factor and other parameters of such a channel. The cooling application has been described before; this paper reports recent studies of a system that includes two novel concepts to accomplish capture and coalescing via a slip-controlled helical channel.

TUP202	Non-Scaling FFAG Proton Driver for Project X	1199
	C. Johnstone, D.V. Neuffer Fermilab, Batavia, USA M. Berz, K. Makino MSU, East Lansing, Michigan, USA L.J. Jenner, J. Pasternak Imperial College of Science and Technology, Department of Physics, London, United Kingdom P. Snopok IIT, Chicago, Illinois, USA
	The next generation of high-energy physics experiments requires high intensity protons at multi-GeV energies. Fermilab’s HEP program, for example, requires an 8-GeV proton source to feed the Main Injector to create a 2 MW neutrino beams in the near term and would require a 4 MW pulsed proton beam for a potential Neutrino Factory or Muon Collider in the future. High intensity GeV proton drivers are difficult at best with conventional re-circulating accelerators, encountering duty cycle and space-charge limits in the synchrotron and machine size and stability concerns in the weaker-focusing cyclotrons. Only an SRF linac, which has the highest associated cost and footprint, has been considered. Recent innovations in FFAG design, however, have promoted another re-circulating candidate, the Fixed-field Alternating Gradient accelerator (FFAG), as an attractive, but as yet unexplored, alternative. Its strong focusing optics coupled to large transverse and longitudinal acceptances would serve to alleviate space charge effects and achieve higher bunch charges than possible in a synchrotron and presents an upgradeable option from the 2 MW to the 4 MW program.

WEP204	An FFAG Accelerator for Project X	1867
	D.V. Neuffer, L.J. Jenner, C. Johnstone Fermilab, Batavia, USA J. Pasternak STFC/RAL, Chilton, Didcot, Oxon, United Kingdom
	The next generation of high-energy physics experiments requires high intensity protons in the multi-GeV energy range for efficient production of secondary beams. The Fermilab long-term future requires an 8 GeV proton source to feed the Main Injector for a 2 MW neutrino beam source in the immediate future and to provide 4 MW pulsed proton beam for a future neutrino factory or muon collider. We note that a 3GeV cw linac matched to a 3–8 GeV FFAG ring could provide beam for both of these mission needs, as well as the cw 3 GeV experiments, and would be a natural and affordable scenario. We present details of possible scenarios and outline future design and research directions.

WEP249	Intense Muon Beams for Experiments at Project X	1951
	C.M. Ankenbrandt, R.P. Johnson, C. Y. Yoshikawa Muons, Inc, Batavia, USA V.S. Kashikhin, D.V. Neuffer Fermilab, Batavia, USA J. Miller BUphy, Boston, Massachusetts, USA R.A. Rimmer JLAB, Newport News, Virginia, USA
	Funding: Supported in part by DOE SBIR grant DE-SC00002739 A coherent approach for providing muon beams to several experiments for the intensity-frontier program at Project X is described. Concepts developed for the front end of a muon collider/neutrino factory facility, such as phase rotation and ionization cooling, are applied, but with significant differences. High-intensity experiments typically require high-duty-factor beams pulsed at a time interval commensurate with the muon lifetime. It is challenging to provide large RF voltages at high duty factor, especially in the presence of intense radiation and strong magnetic fields, which may preclude the use of superconducting RF cavities. As an alternative, cavities made of materials such as ultra-pure Al and Be, which become very good - but not super - conductors at cryogenic temperatures, can be used.

THP025	A Cooled Generalized Multiple Target System to Create Positrons for a Compact Tunable Intense Gamma Ray Source	2169
	C. Y. Yoshikawa, C.M. Ankenbrandt Muons, Inc, Batavia, USA A. Afanasev Hampton University, Hampton, Virginia, USA D.V. Neuffer Fermilab, Batavia, USA
	Funding: This work was funded by Pacific Northwest National Laboratory which is operated for the U.S. Department of Energy by Battelle Memorial Institute under Contract DE-AC06-76RLO 1830. A compact tunable gamma ray source has many potential uses in medical and industrial applications. One novel scheme to produce an intense beam of gammas relies on the ability to create a high flux of positrons, which are produced by an electron beam on a high Z target. We present an innovative system which allows for a nearly arbitrary targeting geometry that supports multiple targets, whose optimal design is allowed to be driven by the physics of the positron production processes, while naturally supporting cooling of the targets.

THP110	Front End Energy Deposition and Collimation Studies for IDS-NF	2333
	C.T. Rogers STFC/RAL/ASTeC, Chilton, Didcot, Oxon, United Kingdom D.V. Neuffer Fermilab, Batavia, USA P. Snopok IIT, Chicago, Illinois, USA
	Funding: Work supported by DOE, STFC. The function of the Neutrino Factory front end is to reduce the energy spread and size of the muon beam to a manageable level that will allow reasonable throughput to subsequent system components. Since the Neutrino Factory is a tertiary machine (protons to pions to muons), there is an issue of large background from the pion-producing target. The implications of energy deposition in the front end lattice for the Neutrino Factory are addressed. Several approaches to mitigating the effect are proposed and discussed, including proton absorbers, chicanes, beam collimation, and shielding.

Paper

Title

Page

Muon Capture for the Front End of a μ+μ- Collider

157

D.V. Neuffer
Fermilab, Batavia, USA
C. Y. Yoshikawa
Muons, Inc, Batavia, USA

We discuss the design of the muon capture front end for a μ±μ- Collider. In the front end, a proton bunch on a target creates secondary pions that drift into a capture transport channel, decaying into muons. A sequence of rf cavities forms the resulting muon beams into strings of bunches of differing energies, aligns the bunches to (nearly) equal central energies, and initiates ionization cooling. The muons are then cooled and accelerated to high energy into a storage ring for high-energy high luminosity collisions. Our initial design is based on the somewhat similar front end of the International Design Study (IDS) neutrino factory.

MOP047

Helical Channels with Variable Slip Factor for Neutrino Factories and Muon Colliders

187

C. Y. Yoshikawa, C.M. Ankenbrandt
Muons, Inc, Batavia, USA
D.V. Neuffer, K. Yonehara
Fermilab, Batavia, USA

Funding: Supported in part by DOE SBIR grant DE-SC0002739.
In order to realize a muon collider or a neutrino factory based on a muon storage ring, the muons must be captured and cooled efficiently. For a muon collider, the resulting train of bunches should be coalesced into a single bunch. Design concepts for a system to capture, cool, and coalesce a muon beam are described here. In particular, variants of a helical channel are used, taking advantage of the ability to vary the slip factor and other parameters of such a channel. The cooling application has been described before; this paper reports recent studies of a system that includes two novel concepts to accomplish capture and coalescing via a slip-controlled helical channel.

TUP202

Non-Scaling FFAG Proton Driver for Project X

1199

C. Johnstone, D.V. Neuffer
Fermilab, Batavia, USA
M. Berz, K. Makino
MSU, East Lansing, Michigan, USA
L.J. Jenner, J. Pasternak
Imperial College of Science and Technology, Department of Physics, London, United Kingdom
P. Snopok
IIT, Chicago, Illinois, USA

The next generation of high-energy physics experiments requires high intensity protons at multi-GeV energies. Fermilab’s HEP program, for example, requires an 8-GeV proton source to feed the Main Injector to create a 2 MW neutrino beams in the near term and would require a 4 MW pulsed proton beam for a potential Neutrino Factory or Muon Collider in the future. High intensity GeV proton drivers are difficult at best with conventional re-circulating accelerators, encountering duty cycle and space-charge limits in the synchrotron and machine size and stability concerns in the weaker-focusing cyclotrons. Only an SRF linac, which has the highest associated cost and footprint, has been considered. Recent innovations in FFAG design, however, have promoted another re-circulating candidate, the Fixed-field Alternating Gradient accelerator (FFAG), as an attractive, but as yet unexplored, alternative. Its strong focusing optics coupled to large transverse and longitudinal acceptances would serve to alleviate space charge effects and achieve higher bunch charges than possible in a synchrotron and presents an upgradeable option from the 2 MW to the 4 MW program.

WEP204

An FFAG Accelerator for Project X

1867

D.V. Neuffer, L.J. Jenner, C. Johnstone
Fermilab, Batavia, USA
J. Pasternak
STFC/RAL, Chilton, Didcot, Oxon, United Kingdom

The next generation of high-energy physics experiments requires high intensity protons in the multi-GeV energy range for efficient production of secondary beams. The Fermilab long-term future requires an 8 GeV proton source to feed the Main Injector for a 2 MW neutrino beam source in the immediate future and to provide 4 MW pulsed proton beam for a future neutrino factory or muon collider. We note that a 3GeV cw linac matched to a 3–8 GeV FFAG ring could provide beam for both of these mission needs, as well as the cw 3 GeV experiments, and would be a natural and affordable scenario. We present details of possible scenarios and outline future design and research directions.

WEP249

Intense Muon Beams for Experiments at Project X

1951

C.M. Ankenbrandt, R.P. Johnson, C. Y. Yoshikawa
Muons, Inc, Batavia, USA
V.S. Kashikhin, D.V. Neuffer
Fermilab, Batavia, USA
J. Miller
BUphy, Boston, Massachusetts, USA
R.A. Rimmer
JLAB, Newport News, Virginia, USA

Funding: Supported in part by DOE SBIR grant DE-SC00002739
A coherent approach for providing muon beams to several experiments for the intensity-frontier program at Project X is described. Concepts developed for the front end of a muon collider/neutrino factory facility, such as phase rotation and ionization cooling, are applied, but with significant differences. High-intensity experiments typically require high-duty-factor beams pulsed at a time interval commensurate with the muon lifetime. It is challenging to provide large RF voltages at high duty factor, especially in the presence of intense radiation and strong magnetic fields, which may preclude the use of superconducting RF cavities. As an alternative, cavities made of materials such as ultra-pure Al and Be, which become very good - but not super - conductors at cryogenic temperatures, can be used.

THP025

A Cooled Generalized Multiple Target System to Create Positrons for a Compact Tunable Intense Gamma Ray Source

2169

C. Y. Yoshikawa, C.M. Ankenbrandt
Muons, Inc, Batavia, USA
A. Afanasev
Hampton University, Hampton, Virginia, USA
D.V. Neuffer
Fermilab, Batavia, USA

Funding: This work was funded by Pacific Northwest National Laboratory which is operated for the U.S. Department of Energy by Battelle Memorial Institute under Contract DE-AC06-76RLO 1830.
A compact tunable gamma ray source has many potential uses in medical and industrial applications. One novel scheme to produce an intense beam of gammas relies on the ability to create a high flux of positrons, which are produced by an electron beam on a high Z target. We present an innovative system which allows for a nearly arbitrary targeting geometry that supports multiple targets, whose optimal design is allowed to be driven by the physics of the positron production processes, while naturally supporting cooling of the targets.

THP110

Front End Energy Deposition and Collimation Studies for IDS-NF

2333

C.T. Rogers
STFC/RAL/ASTeC, Chilton, Didcot, Oxon, United Kingdom
D.V. Neuffer
Fermilab, Batavia, USA
P. Snopok
IIT, Chicago, Illinois, USA

Funding: Work supported by DOE, STFC.
The function of the Neutrino Factory front end is to reduce the energy spread and size of the muon beam to a manageable level that will allow reasonable throughput to subsequent system components. Since the Neutrino Factory is a tertiary machine (protons to pions to muons), there is an issue of large background from the pion-producing target. The implications of energy deposition in the front end lattice for the Neutrino Factory are addressed. Several approaches to mitigating the effect are proposed and discussed, including proton absorbers, chicanes, beam collimation, and shielding.