31 Matching Results

Search Results

Advanced search parameters have been applied.

Muon colliders and neutrino factories

Description: Over the last decade there has been significant progress in developing the concepts and technologies needed to produce, capture and accelerate {Omicron}(10{sup 21}) muons/year. This development prepares the way for a new type of neutrino source (Neutrino Factory) and a new type of very high energy lepton-antilepton collider (Muon Collider). This article reviews the motivation, design and R&D for Neutrino Factories and Muon Colliders.
Date: September 1, 2010
Creator: Geer, S.
Partner: UNT Libraries Government Documents Department

From Neutrino Factory to Muon Collider

Description: Both Muon Colliders and Neutrino Factories require a muon source capable of producing and capturing {Omicron}(10{sup 21}) muons/year. This paper reviews the similarities and differences between Neutrino Factory and Muon Collider accelerator complexes, the ongoing R&D needed for a Muon Collider that goes beyond Neutrino Factory R&D, and some thoughts about how a Neutrino Factory on the CERN site might eventually be upgraded to a Muon Collider.
Date: January 1, 2010
Creator: Geer, S.
Partner: UNT Libraries Government Documents Department

Physics at the Fermilab Tevatron Proton-Antiproton Collider

Description: These lectures discuss a selection of QCD and Electroweak results from the CDF and D0 experiments at the Fermilab Tevatron Proton-Antiproton Collider. Results are presently based on data samples of about 20 pb{sup {minus}1} at a center-of-mass energy of 1.8 TeV. Results discussed include jet production, direct photon production, W mass and width measurements, the triboson coupling, and most exciting of all, evidence for top quark production.
Date: August 1, 1994
Creator: Geer, S.
Partner: UNT Libraries Government Documents Department

Neutrino factory physics study status and an entry level scenario

Description: The status of an ongoing neutrino factory physics study at Fermilab is described, together with a personal view of the parameters required for an entry-level neutrino factory. Recent measurements of atmospheric muon neutrino ({nu}{sub {mu}}) fluxes from the Super-Kamiokande (SuperK) collaboration have shown an aximuth-dependent {r{underscore}arrow} baseline dependent-depletion that strongly suggests neutrino oscillations of the type {nu}{sub {mu}} {r{underscore}arrow} {nu}{sub {mu}}. Since the atmospheric {nu}{sub e} flux is not similarly depleted, {nu}{sub x} cannot be {nu}{sub e}, and must therefore be either {nu}{sub {tau}}, or {nu}{sub s} (a sterile neutrino). These observations have inspired many theoretical papers, several neutrino oscillation experiments proposals, and much interest in the physics community. This interest is well motivated. Understanding the neutrino-mass hierarchy and the mixing matrix that drives flavor oscillations may provide clues that lead to a deeper understanding of physics at very high mass-scales and insights into the physics associated with the existence of more than one lepton flavor. Hence, there is a strong incentive to find a way of measuring the neutrino flavor mixing matrix, confirm and oscillation scheme (three-flavor mixing, four-flavor, n-flavor ?), and determine which mass eigenstate is the heaviest (and which is the lightest). This will require a further generation of accelerator based experiments beyond those currently proposed.
Date: February 1, 2000
Creator: Geer, S.
Partner: UNT Libraries Government Documents Department

Workshop on physics at the first muon collider and front-end of a muon collider: A brief summary

Description: In November 1997 a workshop was held at Fermilab to explore the physics potential of the first muon collider, and the physics potential of the accelerator complex at the `front-end` of the collider. An extensive physics program emerged from the workshop. This paper attempts to summarize this physics program and to identify the main conclusions from the workshop. 14 refs., 1 fig., 5 tabs.
Date: February 1, 1998
Creator: Geer, S.
Partner: UNT Libraries Government Documents Department

Summary of the Superconducting RF Linac for Muon Collider and Neutrino Factory

Description: Project-X is a proposed project to be built at Fermi National Accelerator Laboratory with several potential missions. A primary part of the Project-X accelerator chain is a Superconducting linac, and In October 2009 a workshop was held to concentrate on the linac parameters. The charge of the workshop was to 'focus only on the SRF linac approaches and how it can be used'. The focus of Working Group 2 of this workshop was to evaluate how the different linac options being considered impact the potential realization of Muon Collider (MC) and Neutrino Factory (NF) applications. In particular the working group charge was, 'to investigate the use of a multi-megawatt proton linac to target, phase rotate and collect muons to support a muon collider and neutrino factory'. To focus the working group discussion, three primary questions were identified early on, to serve as a reference: (1) What are the proton source requirements for muon colliders and neutrino factories? (2) What are the issues with respect to realizing the required muon collider and neutrino factory proton sources - (a) General considerations and (b) Considerations specific to the two linac configurations identified by Project-X? (3) What things need to be done before we can be reasonably confident that ICD1/ICD2 can be upgraded to provide the neutrino factory/muon collider needs? A number of presentations were given, and are available at the workshop web-site. This paper does not summarize the individual presentations, but rather addresses overall findings as related to the three guiding questions listed above.
Date: January 1, 2010
Creator: Galambos, J.; Ridge, /Oak; Garoby, R.; /CERN; Geer, S. & /Fermilab
Partner: UNT Libraries Government Documents Department

Neutrino factories: realization and physics potential

Description: Neutrino Factories offer an exciting option for the long-term neutrino physics program. This new type of neutrino facility will provide beams with unique properties. Low systematic uncertainties at a Neutrino Factory, together with a unique and precisely known neutrino flavor content, will enable neutrino oscillation measurements to be made with unprecedented sensitivity and precision. Over recent years, the resulting neutrino factory physics potential has been discussed extensively in the literature. In addition, over the last six years the R&D necessary to realize a Neutrino Factory has been progressing, and has developed into a significant international activity. It is expected that, within about five more years, the initial phase of this R&D program will be complete and, if the community chooses to build this new type of neutrino source within the following decade, neutrino factory technology will be ready for the final R&D phase prior to construction. In this paper (1) an overview is given of the technical ingredients needed for a Neutrino Factory, (2) beam properties are described, (3) the resulting neutrino oscillation physics potential is summarized, (4) a more detailed description is given for one representative Neutrino Factory design, and (5) the ongoing R&D program is summarized, and future plans briefly described.
Date: December 1, 2006
Creator: Geer, S.; /Fermilab; Zisman, M.S. & /LBL, Berkeley
Partner: UNT Libraries Government Documents Department

The pixel microtelescope

Description: We describe a vertex and/or tracking detector designed to operate in an environment in which there is a large density of background hits. 2 refs., 2 figs.
Date: October 1, 1996
Creator: Chapman, J. & Geer, S.
Partner: UNT Libraries Government Documents Department

How well do we need to know the beam properties at a neutrino factory?

Description: In principle, a neutrino factory can produce a beam with a well known {nu}{sub e} and {nu}{sub {mu}} flux. In practice, the uncertainties on the muon beam properties will introduce uncertainties into the calculated neutrino fluxes. The authors explore the relationship between the beam systematics and the systematic uncertainties on predicted event rates at a far site. The desired precision with which they must know the beam momentum, direction, divergence, momentum spread, and polarization are discussed.
Date: February 29, 2000
Creator: Geer, S. & Crisan, C.
Partner: UNT Libraries Government Documents Department

The radiation environment in and near high gradient rf cavities.

Description: The radiation environment in and near high gradient rf cavities is very important for the instrumentation of the MUCOOL experiment, since large fluxes of x rays and dark current electrons can interfere with the operation of the muon detectors. We have measured the x ray and dark current spectra from a single cell, 1.3 GHz, and are beginning to make more extensive measurements of a multicelled 805 MHz cavity. The results are consistent with electron field emission, bremsstrahlung and photon absorption/scattering. We discuss ways of minimizing this background and the scaling of these results to other cavities.
Date: July 23, 2001
Creator: Ducas, L.; Norem, J.; Geer, S.; Moretti, A.; Popovic, M. & Solomey, N.
Partner: UNT Libraries Government Documents Department

Searching for antiproton decay at the Fermilab Antiproton Accumulator

Description: This paper describes an experimental search for antiproton decay at the Fermilab Antiproton Accumulator. The E868 (APEX) experimental setup is described. The APEX data is expected to be sensitive to antiproton decay if the antiproton lifetimes is less than a few times 100,000 years.
Date: September 1, 1995
Creator: Geer, S. & Collaboration, E868
Partner: UNT Libraries Government Documents Department

Multijet events at the Tevatron proton-antiproton collider

Description: The characteristics of three-jet, four-jet, and five-jet events observed by the CDF and D0 experiments at the Fermilab Tevatron {bar p}p collider are compared with leading order QCD matrix element predictions, and with the predictions from a parton shower Monte Carlo program.
Date: July 1, 1995
Creator: Geer, S.
Partner: UNT Libraries Government Documents Department

Characterization of the 50 MeV ALS linac beam with optical transition radiation

Description: First experimental results of the optical transition radiation diagnostic at the Beam Test Facility (BTF) are presented. The BTF uses the 50 MeV Advanced Light Source (ALS) injector. Using sensitive CCD cameras single shot energies, spot sizes and divergences can be measured for the lnC/bunch electron beam. The emittance was determined by analyzing optical transition radiation data for various currents of a quadrupole lens.
Date: June 1, 1994
Creator: de Loos, M. J.; van der Geer, S. B. & Leemans, W. P.
Partner: UNT Libraries Government Documents Department

Recent results from the CDF (Collider Detector at Fermilab) experiment at the Tevatron proton-antiproton collider

Description: Recent results from the CDF experiment are described. The Standard Model gives a good description of jet production, and W/Z production and decay. There is no evidence yet for the top quark, for fourth generation quarks, or for deviations from the Standard Model ascribable to quark substructure, supersymmetric particles, or heavy additional W-like or Z-like bosons. Limits are given where applicable. A search for a light Higgs Boson is also described. 11 refs., 24 figs.
Date: September 1, 1989
Creator: Geer, S. (Harvard Univ., Cambridge, MA (USA). High Energy Physics Lab.)
Partner: UNT Libraries Government Documents Department

Recent results from proton-antiproton colliders

Description: New results from the CERN and Fermilab proton-antiproton colliders are summarised. The areas covered are jet physics, direct photon production, W and Z production and decay, heavy flavor production, the search for the top quark, and the search for more exotic phenomena. 46 refs., 20 figs., 4 tabs.
Date: March 1, 1990
Creator: Geer, S. (Harvard Univ., Cambridge, MA (USA). High Energy Physics Lab.)
Partner: UNT Libraries Government Documents Department

Design Concept for nu-STORM: An Initial Very Low-Energy Neutrino Factory

Description: We present a design concept for a {nu} source from a STORage ring for Muons ({nu}STORM). In this initial design a high-intensity proton beam produces {approx}5 GeV pions that provide muons that are captured using 'stochastic injection' within a 3.6 GeV racetrack storage ring. In 'stochastic injection', the {approx}5 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 {approx}3.6 GeV/c ring momentum acceptance and are stored for the muon lifetime of {approx}1000 turns. Muon (and pion) decays in the long straight sections provide neutrino beams of precisely known flux and flavor that can be used for precision measurements of electron and muon neutrino interactions, and neutrino oscillations or disappearance at L/E = {approx}1m/MeV. The facility is described, and variations are discussed.
Date: May 1, 2012
Creator: Bross, A.; Geer, S.; Liu, A.; Neuffer, D.; Popovic, M.; /Fermilab et al.
Partner: UNT Libraries Government Documents Department

Low-Cost High-Concentration Photovoltaic Systems for Utility Power Generation

Description: Under DOE's Technology Pathway Partnership (TPP) program, Amonix, Inc. developed a new generation of high-concentration photovoltaic systems using multijunction technology and established the manufacturing capacity needed to supply multi-megawatt power plants buing using the new Amonix 7700-series solar energy systems. For this effort, Amonix Collaborated with a variety of suppliers and partners to complete project tasks. Subcontractors included: Evonik/Cyro; Hitek; the National Renewable Energy Laboratory (NREL); Raytech; Spectrolab; UL; University of Nevada, Las Vegas; and TUV Rheinland PTL. The Amonix TPP tasks included: Task 1: Multijunction Cell Optimization for Field Operation, Task 2: Fresnel Lens R&D, Task 3: Cell Package Design & Production, Task 4: Standards Compliance and Reliability Testing, Task 5: Receiver Plate Production, Task 6: MegaModule Performance, Task 7: MegaModule Cost Reduction, Task 8: Factory Setup and MegaModule Production, Task 9: Tracker and Tracking Controller, Task 10: Installation and Balance of System (BOS), Task 11: Field Testing, and Task 12: Solar Advisor Modeling and Market Analysis. Amonix's TPP addressed nearly the complete PV value chain from epitaxial layer design and wafer processing through system design, manufacturing, deployment and O&M. Amonix has made progress toward achieving these reduced costs through the development of its 28%+ efficient MegaModule, reduced manufacturing and installation cost through design for manufacturing and assembly, automated manufacturing processes, and reduced O&M costs. Program highlights include: (1) Optimized multijunction cell and cell package design to improve performance by > 10%; (2) Updated lens design provided 7% increased performance and higher concentration; (3) 28.7% DC STC MegaModule efficiency achieved in Phase II exceeded Phase III performance goal; (4) New 16' focal length MegaModule achieved target materials and manufacturing cost reduction; (5) Designed and placed into production 25 MW/yr manufacturing capacity for complete MegaModules, including cell packages, receiver plates, and structures with lenses; (6) Designed and deployed Amonix 7700 ...
Date: March 31, 2012
Creator: McConnell, R.; Garboushian, V.; Gordon, R.; Dutra, D.; Kinsey, G.; Geer, S. et al.
Partner: UNT Libraries Government Documents Department

Using the Fermilab proton source for a muon to electron conversion experiment

Description: The Fermilab proton source is capable of providing 8 GeV protons for both the future long-baseline neutrino program (NuMI), and for a new program of low energy muon experiments. In particular, if the 8 GeV protons are rebunched and then slowly extracted into an external beamline, the resulting proton beam would be suitable for a muon-to-electron conversion experiment designed to improve on the existing sensitivity by three orders of magnitude. We describe a scheme for the required beam manipulations. The scheme uses the Accumulator for momentum stacking, and the Debuncher for bunching and slow extraction. This would permit simultaneous operation of the muon program with the future NuMI program, delivering 10{sup 20} protons per year at 8 GeV for the muon program at the cost of a modest ({approx}10%) reduction in the protons available to the neutrino program.
Date: November 1, 2006
Creator: Ankenbrandt, C.; Bogert, D.; DeJongh, F.; Geer, S.; McGinnis, D.; Neuffer, D. et al.
Partner: UNT Libraries Government Documents Department

Low-energy neutrino factory design

Description: The design of a low-energy (4 GeV) neutrino factory (NF) is described, along with its expected performance. The neutrino factory uses a high-energy proton beam to produce charged pions. The {pi}{sup {+-}} decay to produce muons ({mu}{sup {+-}}), which are collected, accelerated, and stored in a ring with long straight sections. Muons decaying in the straight sections produce neutrino beams. The scheme is based on previous designs for higher energy neutrino factories, but has an improved bunching and phase rotation system, and new acceleration, storage ring, and detector schemes tailored to the needs of the lower energy facility. Our simulations suggest that the NF scheme we describe can produce neutrino beams generated by {approx} 1.4 x 10{sup 21} {mu}{sup +} per year decaying in a long straight section of the storage ring, and a similar number of {mu}{sup -} decays.
Date: July 1, 2009
Creator: Ankenbrandt, C.; /Fermilab /MUONS Inc., Batavia; Bogacz, S.A.; Lab, /Jefferson; Bross, A.; Geer, S. et al.
Partner: UNT Libraries Government Documents Department

Effect of high solenoidal magnetic fields on breakdown voltages of high vacuum 805 MHz cavities

Description: There is an on going international collaboration studying the feasibility and cost of building a muon collider or neutrino factory [1,2]. An important aspect of this study is the full understanding of ionization cooling of muons by many orders of magnitude for the collider case. An important muon ionization cooling experiment, MICE [3], has been proposed to demonstrate and validate the technology that could be used for cooling. Ionization cooling is accomplished by passing a high-emittance muon beam alternately through regions of low Z material, such as liquid hydrogen, and very high accelerating RF Cavities within a multi-Tesla solenoidal field. To determine the effect of very large solenoidal magnetic fields on the generation of dark current, x-rays and on the breakdown voltage gradients of vacuum RF cavities, a test facility has been established at Fermilab in Lab G. This facility consists of a 12 MW 805 MHz RF station and a large warm bore 5 T solenoidal superconducting magnet containing a pill box type cavity with thin removable window apertures. This system allows dark current and breakdown studies of different window configurations and materials. The results of this study will be presented. The study has shown that the peak achievable accelerating gradient is reduced by a factor greater than 2 when solenoidal field of greater than 2 T are applied to the cavity.
Date: October 1, 2005
Creator: Moretti, A.; Bross, A.; Geer, S.; Qian, Z.; Norem, J.; Li, D. et al.
Partner: UNT Libraries Government Documents Department