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Correction of Dipole and IR Quadrupole Nonlinear Content in Large Colliders

Description: The concept of quasilocal (F, C, D) correction of nonlinearities is reviewed. Correction by two or more orders of magnitude is obtained; in addition, separated-function control of the horizontal, coupled and vertical motion becomes possible. Quasi-local correction of dipole nonlinearities is planned for LHC, and will greatly increase the linear specture. The 1990 SSC Site-Specific Conceptual Design includes quasilocal correction in the 20 TeV Collider, but restrictions may limit correction capability. Quasilocal (F, C, D) correction may also be useful in the SSC 2-TeV High Energy Booster (HEB). In high-luminosity collider mode, the nonlinear effects of the interaction-region (IR) quadrupoles may be dominant; these errors may also be compensated quasilocally. Extensions of the (F, C, D) concept for IR correction, which exploit the restricted IR symmetry, are also suggested.
Date: January 1, 1991
Creator: Neuffer, David
Partner: UNT Libraries Government Documents Department

Recent Results on Muon Capture for a Neutrino Factory and Muon Collider

Description: Scenarios for capture, bunching and phase-energy rotation of {mu}'s from a proton source have been developed. The goal is capture of a maximal number of muons in a string of rf bunches with applications in neutrino factories and {mu}{sup +}-{mu}{sup -} colliders. In this note we begin with the bunching, phase rotation and cooling scenario used in neutrino factory study 2B and adapted by R. Palmer as the initial stage of a {mu}{sup +}-{mu}{sup -} collider scenario. However the scenario produces a relatively large number of bunches that must be recombined for maximal collider luminosity. In this paper we modify the scenario to obtain a smaller number of bunches, and, after some optimization, obtain cases that are better for both n-factory and collider scenarios. We describe these examples and consider some variations toward an optimal {nu}-factory + collider scenario.
Date: January 1, 2008
Creator: Neuffer, David
Partner: UNT Libraries Government Documents Department

A discussion of bunched beam stochastic cooling

Description: The analysis of Herr and Mohl[1] is used as a basis for a discussion of bunched beam cooling in the Fermilab recycler and the Tevatron. Differences between the two cooling regimes are discussed. Criteria discussed in that paper imply the failure of stochastic cooling in the Tevatron while permitting the success of stochastic cooling in the Recycler. These ''predictions'' are in agreement with observations.
Date: August 1, 2005
Creator: Neuffer, David
Partner: UNT Libraries Government Documents Department

Parameters for a 'Project-X'-based Muon Collider

Description: A set of parameters for a 4TeV {mu}{sup +}-{mu}{sup -} Collider based on the use of 'Project-X' as the proton source for p production is presented. The scenario uses 56 GeV protons from the 'Main Injector', bunches these protons in a new buncher to 9 {approx} 1m long bunches. The estimated luminosity is {approx} 4 x 10{sup 34} cm{sup -2}s{sup -1}, with several potential upgrade possibilities.
Date: August 1, 2007
Creator: Neuffer, David
Partner: UNT Libraries Government Documents Department

Proton beam formation at Fermilab for Mu2e (and for NF/MC)

Description: Proton bunch formation from the Fermilab proton sources for the mu2e experiment is discussed. In the initial scenario a single intense h=1 bunch is formed in the Accumulator/Debuncher, with slow extraction providing the required spill. However, the mu2e experiment could use h=4 bunching in the Accumulator rather than h=1, with the 4 bunches fed one at a time into the more isochronous Debuncher for slow extraction. The h=4 variant has several advantages and a few disadvantages, and can reduce peak beam intensities, and therefore improve space charge limits. The method can be extended to project X to enable high duty cycle extraction within space charge limits. A further extension should make possible an accumulator/buncher scenario that can provide 8 GeV short bunches for a neutrino factory and/or muon collider scenario.
Date: October 1, 2009
Creator: Neuffer, David
Partner: UNT Libraries Government Documents Department

Low-energy ionization cooling of ions for beta beam sources

Description: Rubbia et al.[1] have recently suggested that multiturn passage of a low-energy ion beam (v/c {approx_equal} 0.1) through a low-Z target can be used in the production of ions useable for beta-beam sources and that ionization cooling techniques can increase the circulating beam lifetime and thus enhance that production. Some parameters in their initial discussion are somewhat optimistic, and the conditions for 3-D cooling are not completely developed. In the present paper we reconsider some features of the scenarios and suggest some variations that may be more practical. While 3-D cooling is possible at these energies, mixing of longitudinal motion with both horizontal and vertical motion is necessary to obtain simultaneous cooling in all dimensions; we suggest lattice variations that would be needed. Direct and reverse kinematics are described and explored.
Date: October 1, 2007
Creator: Neuffer, David
Partner: UNT Libraries Government Documents Department

Ionization cooling in a low-energy proton storage ring

Description: At the FFAG05 meeting, Mori and Okabe presented a scenario in which the lifetime of protons in a low-energy storage ring ({approx}10 MeV) is extended by energy-loss in a wedge foil, and this enables greater neutron production from the foil. The lifetime extension is due to the cooling effect of this energy loss. We have previously analyzed ionization cooling for muons at optimal cooling energies. The same equations, with appropriate adaptations, can be used to analyze the dynamic situation for proton-material interactions at low energies. In this note we discuss this extension and calculate cooling and heating effects at these very different parameters. The ring could provide a practical application of ionization cooling methods.
Date: March 1, 2006
Creator: Neuffer, David V.
Partner: UNT Libraries Government Documents Department

Beam Optics for the CEBAF FEL Proposal

Description: Beam from the 45 MeV CEBAF injector linac can be used to drive a high-power infrared (IR) free electron laser (FEL), while the 400 MeV north linac beam can drive an ultraviolet (UV) FEL. The FELs require separation of high-intensity FEL driver bunches from the CEBAF nuclear physics beams into transport sections containing wigglers within optical cavities with appropriate matching. The FEL systems must fit within the CEBAF accelerator tunnel. Optical solutions for both the IR and UV FEL beam transports are described and discussed.
Date: August 1, 1992
Creator: Bisognano, Joseph; Douglas, David & Neuffer, David
Partner: UNT Libraries Government Documents Department

Muon Collider: Muon Generation, Capture and Cooling

Description: A {mu}{sup +} -{mu}{sup -} collider requires a high-intensity proton source for {pi}-production, a high-acceptance {pi}-{mu} decay channel, a {mu}-cooling system, a rapid acceleration system, and a high-luminosity collider ring for the collision of short, intense {mu}{sup +} -{mu}{sup -} bunches. Critical problems exist in developing and compressing high-energy proton bunches for producing {pi}�s, in capturing {pi}�s and their decay {mu}�s, and in cooling {mu}�s into a compressed phase-space at which high luminosity collisions are possible. These problems and some possible solutions are discussed; the current {mu}{sup +} -{mu}{sup -} collider research program is described
Date: February 16, 1999
Creator: Neuffer, David
Partner: UNT Libraries Government Documents Department

From a {nu} factory to {mu} super + mu super {minus} Colliders

Description: An important feature of a {mu}-storage ring {nu}-source is that it can be extended to the possibility of a future high-energy muon collider. The neutrino source provides a useful physics device that initiates key technologies required for future {mu}{sup +}-{mu}{sup {minus}} Colliders, but with much less demanding parameter requirements. These technologies include high-intensity {mu}-production, {mu}-capture, {mu}-cooling, {mu}-acceleration and multiturn {mu} storage rings. {mu}{sup +}-{mu}{sup {minus}} colliders require a similar number of muons, but they require that the muons be cooled to a much smaller phase space and formed into a small number of bunches, and both positive and negative bunches must be simultaneously captured. These differences are discussed, and the extension of the {nu}-source to {mu}{sup +}-{mu}{sup {minus}} collider specifications is described.
Date: December 21, 2000
Creator: Neuffer, David
Partner: UNT Libraries Government Documents Department

Extensions of the longitudinal envelope equation

Description: Recently, longitudinal space charge effects have become of increased importance in a variety of dynamical situations. The CEBAF FEL injector beam dynamics shows large space-charge effects, even at 10 MeV ({gamma} {approx} 20). Space-charge dominated longitudinal motion has also been studied in the IUCF ion storage ring. Previously a longitudinal envelope equation with a self-consistent phase-space distribution has been developed, and has been of considerable use in analyzing the motion of these cases. Longitudinal motion in detailed agreement with this envelope equation has been observed at the U. of Maryland Laboratory for Plasma Research, and at the GSI electron cooling storage ring ESR, as well as at the IUCF. However, the initial presentation in ref. 4 used non-relativistic linear-accelerator bunching motion as a simplifying approximation in order to avoid inadvertent errors and minimize misprints, and must be adapted to include relativistic and/or synchrotron effects. In the present note we extend the envelope equation formulae to include relativistic, synchrotron, and acceleration effects, and define the various factors in the equations in explicit detail. The object is to obtain a set of debugged formulae for these extended cases, with all of the various factors defined explicitly, so that the formulae can be used as a reference without repetitive rederivations. The usual ambiguities over emittance definitions and units and {beta}, {gamma}, g factors should be resolved. The reader (or readers) is invited to discover any remaining errors, ambiguities or misprints for removal in the next edition.
Date: April 30, 1997
Creator: Neuffer, David
Partner: UNT Libraries Government Documents Department

Evolutionary algorithm for the neutrino factory front end design

Description: The Neutrino Factory is an important tool in the long-term neutrino physics program. Substantial effort is put internationally into designing this facility in order to achieve desired performance within the allotted budget. This accelerator is a secondary beam machine: neutrinos are produced by means of the decay of muons. Muons, in turn, are produced by the decay of pions, produced by hitting the target by a beam of accelerated protons suitable for acceleration. Due to the physics of this process, extra conditioning of the pion beam coming from the target is needed in order to effectively perform subsequent acceleration. The subsystem of the Neutrino Factory that performs this conditioning is called Front End, its main performance characteristic is the number of the produced muons.
Date: January 1, 2009
Creator: Poklonskiy, Alexey A.; U., /Michigan State; Neuffer, David & /Fermilab
Partner: UNT Libraries Government Documents Department

Muon cooling in a quadrupole magnet channel

Description: As discussed before,[1] a cooling channel using quadrupole magnets in a FODO transport channel can be used for initial cooling of muons. In the present note we discuss this possibility of a FODO focusing channel for cooling, and we present ICOOL simulations of muon cooling within a FODO channel. We explore a 1.5m cell-length cooling channel that could be used for the initial transverse cooling stage of a muon collider or neutrino factory.
Date: October 1, 2007
Creator: Neuffer, David; /Fermilab; Poklonskiy, A. & U., /Michigan State
Partner: UNT Libraries Government Documents Department

Design Considerations for Simultaneous FEL and Nuclear Physics Operation at CEBAF

Description: As conceived in a recent design study, electron beams of quite distinct character would be provided for nuclear physics experiments and FEL wigglers at CEBAF. When full nuclear physics operation begins, coordination between these two programs becomes critical. FEL operation requires electron bunches carrying charge of 120 pC at repetition rates of 2.5 and 7.5 MHz, whereas the nuclear physics users need a relatively small charge per bunch, ~ 0.13 pC, but at a repetition rate of 1.5 GHz. To allow maximal operation of the FEL facility without interfering with CEBAF's primary mission of conducting nuclear physics research, the principal mode of operation should accelerate and deliver the two disparate beams simultaneously with negligible degradation of beam quality. Various RF power, RF control, wakefield, and beam transport questions that are encountered in designing for concurrent operation are discussed.
Date: August 1, 1991
Creator: Yunn, Byung; Douglas, David; Neuffer, David; Krafft, Geoffrey; Bisognano, Joseph & Simrock, Stefan
Partner: UNT Libraries Government Documents Department

Use of Helical Transport Channels for Bunch Recombination

Description: Cooling scenarios for a high-luminosity Muon Collider require bunch recombination for optimal luminosity. In this report we note that the tunable chronicity property of a helical transport channel (HTC) makes it a desirable component of a bunch recombiner. A large chronicity HTC is desirable for the bunch recombining transport, while more isochronous transport may be preferred for rf manipulations. Scenarios for bunch recombination are presented, with initial 1-D simulations, in order to set the stage for future 3-D simulation and optimization. HTC transports may enable a very compact bunch recombiner.
Date: March 1, 2010
Creator: Neuffer, David; Yonehara, Katsuya; /Fermilab; Yoshikawa, Cary & /MUONS Inc., Batavia
Partner: UNT Libraries Government Documents Department

Exploration of ion-antiproton instabilities in the Recycler Ring

Description: Instabilities driven by ions (or electrons) trapped within the space charge potential of a circulating beam are common in accelerators and storage rings. In the recycler, the stored antiproton ({bar p}) beam could trap positive ions (H{sub 2}{sup +}, CO{sup +}, etc.). Conditions for trapping are discussed, and trapping potentials are calculated. Ion trapping can be reduced by clearing electrodes, a beam-free gap (or gaps), and beam shaking. Tune shifts, coherent instabilities and other effects of trapped ions on stored {bar p}'s are discussed. A ''fast-ion'' instability mode is also possible. Experiments to determine conditions and consequences of such instability in the recycler are discussed.
Date: August 4, 2004
Creator: Neuffer, David V.
Partner: UNT Libraries Government Documents Department

IDR muon capture front end and variations

Description: The (International Design Report) IDR neutrino factory scenario for capture, bunching, phase-energy rotation and initial cooling of {mu}'s produced from a proton source target is explored. It requires a drift section from the target, a bunching section and a {phi}-{delta}E rotation section leading into the cooling channel. The rf frequency changes along the bunching and rotation transport in order to form the {mu}'s into a train of equal-energy bunches suitable for cooling and acceleration. Optimization and variations are discussed. An important concern is rf limitations within the focusing magnetic fields; mitigation procedures are described. The method can be extended to provide muons for a {mu}{sup +}-{mu}{sup -} Collider; variations toward optimizing that extension are discussed.
Date: December 1, 2010
Creator: Neuffer, David; /Fermilab; Prior, Gersende; /CERN; Rogers, Christopher; /Rutherford et al.
Partner: UNT Libraries Government Documents Department

A Charge Separation Study to Enable the Design of a Complete Muon Cooling Channel

Description: The most promising designs for 6D muon cooling channels operate on a specific sign of electric charge. In particular, the Helical Cooling Channel (HCC) and Rectilinear RFOFO designs are the leading candidates to become the baseline 6D cooling channel in the Muon Accelerator Program (MAP). Time constraints prevented the design of a realistic charge separator, so a simplified study was performed to emulate the effects of charge separation on muons exiting the front end of a muon collider. The output of the study provides particle distributions that the competing designs will use as input into their cooling channels. We report here on the study of the charge separator that created the simulated particles.
Date: December 1, 2013
Creator: Yoshikawa, C.; Ankenbrandt, Charles M.; Johnson, Rolland P.; Derbenev, Yaroslav; Morozov, Vasiliy; Neuffer, David et al.
Partner: UNT Libraries Government Documents Department

Status Report on the CEBAF IR and UV FELs

Description: The CEBAF five pass recirculating, superconducting linac, being developed as a high power electron source for nuclear physics, is also an ideal FEL driver.The 45 MeV front end linac is presently operational with a CW (low peak current) nuclear physics gun and has met all CEBAF performance specifications including low emittance and energy spread (< 1 * 10^-4). Progress will be reported in commissioning.This experience leads to predictions of excellent FEL performance.Initial designs reported last year have been advanced.Using the output of a high charge DC photoemission gun under development with a 6 cm period wiggler produces kilowatt output powers in the 3.6 to 17 micrometer range in the fundamental.Third harmonic operation extends IR performance down to 1.2 micrometer.Beam at energies up to 400 MeV from the first full CEBAF linac will interact in a similar but longer wiggler to yield kilowatt UV light production at wavelengths as short as 0.15 micrometers.Full power FEL
Date: July 1, 1993
Creator: Leemann, Christoph; Bisognano, Joseph; Douglas, David; Harwood, Leigh; Krafft, Geoffrey; Liger, Philippe et al.
Partner: UNT Libraries Government Documents Department

Use of the CEBAF Accelerator for IR and UV Free Electron Lasers

Description: The CEBAF superconducting linac is capable of accelerating electron beams suitable for driving high-power free-electron lasers. The 45 MeV injector linac with a 6 cm period wiggler can produce kilowatt output powers of infrared light (3.6-17 micrometer), while the 400 MeV north linac can produce ultraviolet light (~200 nm) at similar powers. The FELs require the addition of a high-peak intensity electron source (~ 60 A peak current) and extraction beam lines to wigglers with appropriate electron and photon optics. FEL operation is compatible with simultaneous baseline CEBAF nuclear physics operation. A design for a CEBAF-based FEL facility has been developed. The current status of the FEL project is reported.
Date: August 1, 1992
Creator: Yunn, Byung; Sinclair, Charles; Leemann, Christoph; Rode, Claus; Douglas, David; Neuffer, David et al.
Partner: UNT Libraries Government Documents Department

High-energy high luminosity mu{sup +}mu{sup {minus}} collider design

Description: The authors discuss the design of a high luminosity (10{sup 35} cm{sup {minus}2}s{sup {minus}1}), high energy (2+2 TeV) mu{sup +}mu{sup {minus}} collider, starting from the proton accelerator needed to generate the muon beams and proceeding through the muon storage ring.
Date: May 1, 1995
Creator: Palmer, Robert B.; Fernow, Richard; Gallardo, Juan C.; Lee, Y.Y.; Torun, Yagmur; Neuffer, David et al.
Partner: UNT Libraries Government Documents Department

A Complete Scheme of Ionization Cooling for a Muon Collider

Description: The conclusions of this report are: (1) New 1.5 TeV Collider lattice has more conservative IP parameters--(a) Luminosity 1 x 10{sup 34} achieved with bunch rep rate {approx}12 Hz but requires depth {approx}135 (m) to limit neutrino radiation, (b) Collider ring must be deep (eg 135 m of ILC) to control neutrino radiation, and (c) Proton driver ({approx}4 MW) is challenging; (2) Complete cooling scheme achieves required muon parameters--All components simulated (at some level) with realistic parameters, but much work remains; (3) Possible problem with rf breakdown in specified magnetic fields--Solutions with gas in cavities appear to work, and designs with open cell rf are promising; and (4) Lower cost acceleration possible using pulsed magnets in synchrotrons--Rings fit in Tevatron tunnel, and second ring uses hybrid of fixed and pulsed magnets.
Date: November 1, 2007
Creator: Palmer, Robert B.; Berg, J.Scott; Fernow, Richard C.; Gallardo, Juan Carlos; Kirk, Harold G.; /Brookhaven et al.
Partner: UNT Libraries Government Documents Department