2011 Particle Accelerator Conference - List of Authors (Snopok, P.)

Paper

Title

Page

Simulations of the Tapered Guggenheim 6d Cooling Channel for the Muon Collider

217

P. Snopok
IIT, Chicago, Illinois, USA
G.G. Hanson
UCR, Riverside, California, USA
R. B. Palmer
BNL, Upton, Long Island, New York, USA

Funding: Work is supported by the U.S. Department of Energy.
Recent progress in six-dimensional (6D) cooling simulations for the Muon Collider based on the RFOFO ring layout is presented. In order to improve the performance of the cooling channel a tapering scheme is studied that implies changing the parameters such as cell length, magnetic field strength, RF frequency, and the amount of the absorbing material along the cooling channel. This approach allows us to keep the cooling rates high throughout the process. The results of the simulations carried out in G4beamline are presented.

MOP060

Wedge Absorber Design and Simulation for MICE Step IV

220

C.T. Rogers
STFC/RAL/ASTeC, Chilton, Didcot, Oxon, United Kingdom
L. Coney, G.G. Hanson
UCR, Riverside, California, USA
P. Snopok
IIT, Chicago, Illinois, USA

Funding: Work is supported by the Science and Technology Facilities Council, the U.S. Department of Energy and the U.S. National Science Foundation.
In the Muon Ionization Cooling Experiment (MICE), muons are cooled by passing through material, then through RF cavities to compensate for the energy loss; which reduces the transverse emittance. It is planned to demonstrate longitudinal emittance reduction via emittance exchange in MICE by using a solid wedge absorber in Step IV. Based on the outcome of previous studies, the shape and material of the wedge were chosen. We address here further simulation efforts for the absorber of choice as well as engineering considerations in connection with the absorber support design.

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.

THOCN7

Isochronous (CW) High Intensity Non-scaling FFAG Proton Drivers

2116

C. Johnstone
Fermilab, Batavia, USA
M. Berz, K. Makino
MSU, East Lansing, Michigan, USA
S.R. Koscielniak
TRIUMF, Canada's National Laboratory for Particle and Nuclear Physics, Vancouver, Canada
P. Snopok
IIT, Chicago, Illinois, USA

Funding: Work supported in part under SBIR grant DE-FG02-08ER85222 and by Fermi Research Alliance, under contract DEAC02-07CH11359, both with the U.S. Dept. of Energy
The drive for higher beam power, duty cycle, and reliable beams at reasonable cost has focused world interest on fixed field accelerators, notably FFAGs. High-intensity GeV proton drivers encounter duty cycle and space-charge limits in the synchrotron and machine size concerns in cyclotrons. A 10^-20 MW proton driver is challenging, if even technically feasible, with conventional circular accelerators. Recently, the concept of isochronous orbits has been developed for nonscaling FFAGs using powerful new methodologies in FFAG accelerator design. Isochronous orbits enable the simplicity of fixed RF and, by tailoring the field profile, the FFAG can remain isochronous beyond the energy reach of cyclotrons. With isochronous orbits, the machine proposed here has the high average current advantage and duty cycle of the cyclotron in combination with the strong focusing, smaller losses that are more typical of the synchrotron. With the cyclotron as the current industrial and medical standard, a competing CW FFAG would impact facilities using medical accelerators, proton drivers for neutron production, and accelerator-driven nuclear reactors. This work reports on these new advances.

Slides THOCN7 [2.429 MB]

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
MOP059	Simulations of the Tapered Guggenheim 6d Cooling Channel for the Muon Collider	217
	P. Snopok IIT, Chicago, Illinois, USA G.G. Hanson UCR, Riverside, California, USA R. B. Palmer BNL, Upton, Long Island, New York, USA
	Funding: Work is supported by the U.S. Department of Energy. Recent progress in six-dimensional (6D) cooling simulations for the Muon Collider based on the RFOFO ring layout is presented. In order to improve the performance of the cooling channel a tapering scheme is studied that implies changing the parameters such as cell length, magnetic field strength, RF frequency, and the amount of the absorbing material along the cooling channel. This approach allows us to keep the cooling rates high throughout the process. The results of the simulations carried out in G4beamline are presented.

MOP060	Wedge Absorber Design and Simulation for MICE Step IV	220
	C.T. Rogers STFC/RAL/ASTeC, Chilton, Didcot, Oxon, United Kingdom L. Coney, G.G. Hanson UCR, Riverside, California, USA P. Snopok IIT, Chicago, Illinois, USA
	Funding: Work is supported by the Science and Technology Facilities Council, the U.S. Department of Energy and the U.S. National Science Foundation. In the Muon Ionization Cooling Experiment (MICE), muons are cooled by passing through material, then through RF cavities to compensate for the energy loss; which reduces the transverse emittance. It is planned to demonstrate longitudinal emittance reduction via emittance exchange in MICE by using a solid wedge absorber in Step IV. Based on the outcome of previous studies, the shape and material of the wedge were chosen. We address here further simulation efforts for the absorber of choice as well as engineering considerations in connection with the absorber support design.

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.

THOCN7	Isochronous (CW) High Intensity Non-scaling FFAG Proton Drivers	2116
	C. Johnstone Fermilab, Batavia, USA M. Berz, K. Makino MSU, East Lansing, Michigan, USA S.R. Koscielniak TRIUMF, Canada's National Laboratory for Particle and Nuclear Physics, Vancouver, Canada P. Snopok IIT, Chicago, Illinois, USA
	Funding: Work supported in part under SBIR grant DE-FG02-08ER85222 and by Fermi Research Alliance, under contract DEAC02-07CH11359, both with the U.S. Dept. of Energy The drive for higher beam power, duty cycle, and reliable beams at reasonable cost has focused world interest on fixed field accelerators, notably FFAGs. High-intensity GeV proton drivers encounter duty cycle and space-charge limits in the synchrotron and machine size concerns in cyclotrons. A 10^-20 MW proton driver is challenging, if even technically feasible, with conventional circular accelerators. Recently, the concept of isochronous orbits has been developed for nonscaling FFAGs using powerful new methodologies in FFAG accelerator design. Isochronous orbits enable the simplicity of fixed RF and, by tailoring the field profile, the FFAG can remain isochronous beyond the energy reach of cyclotrons. With isochronous orbits, the machine proposed here has the high average current advantage and duty cycle of the cyclotron in combination with the strong focusing, smaller losses that are more typical of the synchrotron. With the cyclotron as the current industrial and medical standard, a competing CW FFAG would impact facilities using medical accelerators, proton drivers for neutron production, and accelerator-driven nuclear reactors. This work reports on these new advances.
	Slides THOCN7 [2.429 MB]

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.