IPAC2012 - List of Authors (Roberts, T.J.)

Paper

Title

Page

Bethe-Heitler Muon Background at a Muon Collider

214

S.A. Kahn, M.A.C. Cummings, T.J. Roberts
Muons, Inc, Batavia, USA
D. Hedin, A.O. Morris
Northern Illinois University, DeKalb, Illinois, USA
J.F. Kozminski
Lewis University, Romeoville, Illinois, USA

Multi-TeV muon colliders are an important option for a future energy frontier lepton collider since synchrotron radiation in a circular machine is significantly less than that in an electron collider. For a muon collider with 750 GeV μ+μ− with 2×10¹² μ per bunch we would expect 8.6×10⁵ muon decays per meter for the two beams. Muon decays are the source of beam induced backgrounds that can affect the physics. These backgrounds include electrons from muon decays, synchrotron radiation from the decay electrons, hadrons produced by photo-nuclear interactions, coherent and incoherent beam-beam pair production and Bethe-Heitler muon production. This paper will describe a simulation of the B-H muon pair production in a muon collider. These muons can penetrate the collider ring magnets and shielding and possibly enter into the detector regions. The simulation tracks B-H muons produced from electromagnetic shower interactions in collider ring material in the range of ±200 m from the interaction point.

MOPPC083

LinguaFranca - A Graphical User Interface for Accelerator Modeling

331

T.J. Roberts
Muons, Inc, Batavia, USA

This is a proposed project to develop an innovative Graphical User Interface that permits users to construct, explore, optimize, and evaluate accelerator systems efficiently and effectively. While it will be designed with students in mind, accelerator physicists will also find it useful in dealing with the plethora of modeling tools and their different languages. The internal representation of the system is specifically designed to be useable as a text-based description of the system, and to make it easy for users to interface it to essentially any accelerator-modeling tool, regardless of its description language. Many accelerator designers have expressed frustration with the current “Tower of Babel” among modeling programs, and this project will address that directly. In particular, this will make it straightforward to use fast but less realistic programs to design and optimize a system, and then use slower but more realistic programs to evaluate its performance. Graphical interfaces are emphasized, making it easy to construct the system graphically, display the system and its beam, and use on-screen controls to vary parameters and observe their effects immediately.

MOPPC084

G4beamline Code Development

334

T.J. Roberts
Muons, Inc, Batavia, USA

Funding: Supported in part by DoE STTR grant DE-FG02-06ER86281.
G4beamline is a single-particle-tracking simulation program based on Geant4, optimized specifically for beam lines. It is currently used by several hundred physicists and designers around the world, who apply it to a diverse set of interesting problems. As it includes particle decays and interactions, it is applicable to beams for which decays and interactions are important, such as modern muon facilities that involve ionization cooling. Its description language has been designed to be both versatile and user-friendly, and the program includes high-quality visualization and histogramming capabilities. This paper discusses recent code development and new features, and some interesting applications of the program. G4beamline is an open-source program freely available at http://g4beamline.muonsinc.com

MOPPD043

Novel Muon Beam Facilities for Project X at Fermilab

457

C.M. Ankenbrandt, R.J. Abrams, T.J. Roberts, C. Y. Yoshikawa
Muons, Inc, Batavia, USA
D.V. Neuffer
Fermilab, Batavia, USA

Innovative muon beam concepts for intensity-frontier experiments such as muon-to-electron conversion are described. Elaborating upon a previous single-beam idea, we have developed a design concept for a system to generate four high quality, low-energy muon beams (two of each sign) from a single beam of protons. As a first step, the production of pions by 1 and 3 GeV protons from the proposed Project X linac at Fermilab is being simulated and compared with the 8-GeV results from the previous study.

TUEPPB001

Interaction of Muon Beam with Plasma Developed During Ionization Cooling

1110

S. Ahmed
JLAB, Newport News, Virginia, USA
K.B. Beard, T.J. Roberts
Muons, Inc, Batavia, USA
D.M. Kaplan, L.K. Spentzouris
Illinois Institute of Technology, Chicago, Illinois, USA

Muon collider has been envisioned as a future high energy lepton machine. High luminosity can be obtained by the ionization cooling – best suited for muons due to their short life time. In this cooling process, particles ionize material medium in which they lose momentum, thus the normalized emittance is reduced. The ionized medium is called plasma and the ionization density could increase due to the passage of multiple bunches through the material. This means that the incoming beams interact with plasma together with ionizing the medium used for cooling. It is, therefore, important to investigate the effects of background plasma on the incoming bunches. A comprehensive studies of muon beam propagation through plasma medium using EM particle-in-cell simulations. This computational study involves kinetic model, therefore, provides deep insight of the phenomena, which cannot be obtained by the conventional fluid model. The wakes excited by mu+ and mu- are different due to the beam polarity and depends on their relative densities. Externally applied axial magnetic field suppresses the wakes evolved during the interaction. The details of this study will be discussed in the paper.

TUPPD005

Design Concept for Nu-STORM: an Initial “Very Low-Energy Neutrino Factory”

1413

D.V. Neuffer, A.D. Bross, S. Geer, A. Liu, M. Popovic
Fermilab, Batavia, USA
C.M. Ankenbrandt, T.J. Roberts
Muons, Inc, Batavia, USA

Funding: US DOE under contract DE-AC02-07CH11359
We present a design concept for a Nu-source from a STORage ring for Muons - NuSTORM. In this initial design a high-intensity proton beam produces ~5 GeV pions that provide muons that are captured using “stochastic injection” within a ~3.6 GeV racetrack storage ring. In “stochastic injection”, the ~53 GeV pion beam is transported from the target into the storage ring, dispersion-matched into a long straight section. (Circulating and injection orbits are separated by momentum.) Decays within that straight section provide muons that are within the ~2 GeV/c ring momentum acceptance and are stored for the muon lifetime of ~1000 turns. Muon (and pion) decays in the long straight sections provide neutrino beams that can be used for precision measurements of neutrino interactions, and neutrino oscillations or disappearance at L/E=~1 m/MeV. The facility is described and variations are discussed.

THXB01

Interaction of Muon Beam with Plasma Developed During Ionization Cooling

3200

S. Ahmed
JLAB, Newport News, Virginia, USA
K.B. Beard, T.J. Roberts
Muons, Inc, Batavia, USA
D.M. Kaplan, L.K. Spentzouris
Illinois Institute of Technology, Chicago, Illinois, USA

Muon collider has been envisioned as a future high energy lepton machine. High luminosity can be obtained by the ionization cooling – best suited for muons due to their short life time. In this cooling process, particles ionize material medium in which they lose momentum, thus the normalized emittance is reduced. The ionized medium is called plasma and the ionization density could increase due to the passage of multiple bunches through the material. This means that the incoming beams interact with plasma together with ionizing the medium used for cooling. It is, therefore, important to investigate the effects of background plasma on the incoming bunches. A comprehensive studies of muon beam propagation through plasma medium using EM particle-in-cell simulations. This computational study involves kinetic model, therefore, provides deep insight of the phenomena, which cannot be obtained by the conventional fluid model. The wakes excited by mu+ and mu- are different due to the beam polarity and depends on their relative densities. Externally applied axial magnetic field suppresses the wakes evolved during the interaction. The details of this study will be discussed in the paper.

Slides THXB01 [4.584 MB]

THPPR062

Handling GEM*STER Volatile Radioactive Fission Products

4115

M. Notani, C.M. Ankenbrandt, R.P. Johnson, T.J. Roberts
Muons, Inc, Batavia, USA
C. Bowman
ADNA, Los Alamos, New Mexico, USA

A next-generation advanced technology of nuclear power has been developed for many years. One of the promising future reactor designs with accelerator-produced neutrons is GEM*STAR (Green Energy Multiplier*Subcritical Technology for Alternative Reactors) developed by Accelerator Driven Neutron Application (ADNA), which is a subcritical thermal-spectrum reactor operating with molten salt fuel in a graphite matrix. GEM*STAR is able to use natural uranium as well as unreprocessed spent fuel from light-water reactors (LWR), generating as much electricity as the LWR had generated from the same fuel. Since the advanced design of GEM*STAR is quite different from LWR that uses solid nuclear fuel loaded in the Zircaloy, it requires emission control for volatiles emitted from the molten salt fuel, like as radioactive iodine and cesium. The volatiles caught in the helium gas circulating around the core reactor will be trapped in the cryogenic bottles. Numerical simulations to estimate the amount of fission products were performed for the design of confinement of the volatiles. The result of simulation with spent nuclear fuel from LWR is presented.

Paper	Title	Page
MOPPC038	Bethe-Heitler Muon Background at a Muon Collider	214
	S.A. Kahn, M.A.C. Cummings, T.J. Roberts Muons, Inc, Batavia, USA D. Hedin, A.O. Morris Northern Illinois University, DeKalb, Illinois, USA J.F. Kozminski Lewis University, Romeoville, Illinois, USA
	Multi-TeV muon colliders are an important option for a future energy frontier lepton collider since synchrotron radiation in a circular machine is significantly less than that in an electron collider. For a muon collider with 750 GeV μ+μ− with 2×10¹² μ per bunch we would expect 8.6×10⁵ muon decays per meter for the two beams. Muon decays are the source of beam induced backgrounds that can affect the physics. These backgrounds include electrons from muon decays, synchrotron radiation from the decay electrons, hadrons produced by photo-nuclear interactions, coherent and incoherent beam-beam pair production and Bethe-Heitler muon production. This paper will describe a simulation of the B-H muon pair production in a muon collider. These muons can penetrate the collider ring magnets and shielding and possibly enter into the detector regions. The simulation tracks B-H muons produced from electromagnetic shower interactions in collider ring material in the range of ±200 m from the interaction point.

MOPPC083	LinguaFranca - A Graphical User Interface for Accelerator Modeling	331
	T.J. Roberts Muons, Inc, Batavia, USA
	This is a proposed project to develop an innovative Graphical User Interface that permits users to construct, explore, optimize, and evaluate accelerator systems efficiently and effectively. While it will be designed with students in mind, accelerator physicists will also find it useful in dealing with the plethora of modeling tools and their different languages. The internal representation of the system is specifically designed to be useable as a text-based description of the system, and to make it easy for users to interface it to essentially any accelerator-modeling tool, regardless of its description language. Many accelerator designers have expressed frustration with the current “Tower of Babel” among modeling programs, and this project will address that directly. In particular, this will make it straightforward to use fast but less realistic programs to design and optimize a system, and then use slower but more realistic programs to evaluate its performance. Graphical interfaces are emphasized, making it easy to construct the system graphically, display the system and its beam, and use on-screen controls to vary parameters and observe their effects immediately.

MOPPC084	G4beamline Code Development	334
	T.J. Roberts Muons, Inc, Batavia, USA
	Funding: Supported in part by DoE STTR grant DE-FG02-06ER86281. G4beamline is a single-particle-tracking simulation program based on Geant4, optimized specifically for beam lines. It is currently used by several hundred physicists and designers around the world, who apply it to a diverse set of interesting problems. As it includes particle decays and interactions, it is applicable to beams for which decays and interactions are important, such as modern muon facilities that involve ionization cooling. Its description language has been designed to be both versatile and user-friendly, and the program includes high-quality visualization and histogramming capabilities. This paper discusses recent code development and new features, and some interesting applications of the program. G4beamline is an open-source program freely available at http://g4beamline.muonsinc.com

MOPPD043	Novel Muon Beam Facilities for Project X at Fermilab	457
	C.M. Ankenbrandt, R.J. Abrams, T.J. Roberts, C. Y. Yoshikawa Muons, Inc, Batavia, USA D.V. Neuffer Fermilab, Batavia, USA
	Innovative muon beam concepts for intensity-frontier experiments such as muon-to-electron conversion are described. Elaborating upon a previous single-beam idea, we have developed a design concept for a system to generate four high quality, low-energy muon beams (two of each sign) from a single beam of protons. As a first step, the production of pions by 1 and 3 GeV protons from the proposed Project X linac at Fermilab is being simulated and compared with the 8-GeV results from the previous study.

TUEPPB001	Interaction of Muon Beam with Plasma Developed During Ionization Cooling	1110
	S. Ahmed JLAB, Newport News, Virginia, USA K.B. Beard, T.J. Roberts Muons, Inc, Batavia, USA D.M. Kaplan, L.K. Spentzouris Illinois Institute of Technology, Chicago, Illinois, USA
	Muon collider has been envisioned as a future high energy lepton machine. High luminosity can be obtained by the ionization cooling – best suited for muons due to their short life time. In this cooling process, particles ionize material medium in which they lose momentum, thus the normalized emittance is reduced. The ionized medium is called plasma and the ionization density could increase due to the passage of multiple bunches through the material. This means that the incoming beams interact with plasma together with ionizing the medium used for cooling. It is, therefore, important to investigate the effects of background plasma on the incoming bunches. A comprehensive studies of muon beam propagation through plasma medium using EM particle-in-cell simulations. This computational study involves kinetic model, therefore, provides deep insight of the phenomena, which cannot be obtained by the conventional fluid model. The wakes excited by mu+ and mu- are different due to the beam polarity and depends on their relative densities. Externally applied axial magnetic field suppresses the wakes evolved during the interaction. The details of this study will be discussed in the paper.

TUPPD005	Design Concept for Nu-STORM: an Initial “Very Low-Energy Neutrino Factory”	1413
	D.V. Neuffer, A.D. Bross, S. Geer, A. Liu, M. Popovic Fermilab, Batavia, USA C.M. Ankenbrandt, T.J. Roberts Muons, Inc, Batavia, USA
	Funding: US DOE under contract DE-AC02-07CH11359 We present a design concept for a Nu-source from a STORage ring for Muons - NuSTORM. In this initial design a high-intensity proton beam produces ~5 GeV pions that provide muons that are captured using “stochastic injection” within a ~3.6 GeV racetrack storage ring. In “stochastic injection”, the ~53 GeV pion beam is transported from the target into the storage ring, dispersion-matched into a long straight section. (Circulating and injection orbits are separated by momentum.) Decays within that straight section provide muons that are within the ~2 GeV/c ring momentum acceptance and are stored for the muon lifetime of ~1000 turns. Muon (and pion) decays in the long straight sections provide neutrino beams that can be used for precision measurements of neutrino interactions, and neutrino oscillations or disappearance at L/E=~1 m/MeV. The facility is described and variations are discussed.

THXB01	Interaction of Muon Beam with Plasma Developed During Ionization Cooling	3200
	S. Ahmed JLAB, Newport News, Virginia, USA K.B. Beard, T.J. Roberts Muons, Inc, Batavia, USA D.M. Kaplan, L.K. Spentzouris Illinois Institute of Technology, Chicago, Illinois, USA
	Muon collider has been envisioned as a future high energy lepton machine. High luminosity can be obtained by the ionization cooling – best suited for muons due to their short life time. In this cooling process, particles ionize material medium in which they lose momentum, thus the normalized emittance is reduced. The ionized medium is called plasma and the ionization density could increase due to the passage of multiple bunches through the material. This means that the incoming beams interact with plasma together with ionizing the medium used for cooling. It is, therefore, important to investigate the effects of background plasma on the incoming bunches. A comprehensive studies of muon beam propagation through plasma medium using EM particle-in-cell simulations. This computational study involves kinetic model, therefore, provides deep insight of the phenomena, which cannot be obtained by the conventional fluid model. The wakes excited by mu+ and mu- are different due to the beam polarity and depends on their relative densities. Externally applied axial magnetic field suppresses the wakes evolved during the interaction. The details of this study will be discussed in the paper.
	Slides THXB01 [4.584 MB]

THPPR062	Handling GEM*STER Volatile Radioactive Fission Products	4115
	M. Notani, C.M. Ankenbrandt, R.P. Johnson, T.J. Roberts Muons, Inc, Batavia, USA C. Bowman ADNA, Los Alamos, New Mexico, USA
	A next-generation advanced technology of nuclear power has been developed for many years. One of the promising future reactor designs with accelerator-produced neutrons is GEMSTAR (Green Energy MultiplierSubcritical Technology for Alternative Reactors) developed by Accelerator Driven Neutron Application (ADNA), which is a subcritical thermal-spectrum reactor operating with molten salt fuel in a graphite matrix. GEMSTAR is able to use natural uranium as well as unreprocessed spent fuel from light-water reactors (LWR), generating as much electricity as the LWR had generated from the same fuel. Since the advanced design of GEMSTAR is quite different from LWR that uses solid nuclear fuel loaded in the Zircaloy, it requires emission control for volatiles emitted from the molten salt fuel, like as radioactive iodine and cesium. The volatiles caught in the helium gas circulating around the core reactor will be trapped in the cryogenic bottles. Numerical simulations to estimate the amount of fission products were performed for the design of confinement of the volatiles. The result of simulation with spent nuclear fuel from LWR is presented.