48 Matching Results

Search Results

Advanced search parameters have been applied.
in subjects: "Focusing"  
Results: 1 - 24 next
open access

The National Ignition Facility: The world's largest optical system

Description: The National Ignition Facility (NIF), a 192-beam fusion laser, is presently under construction at the Lawrence Livermore National Laboratory with an expected completion in 2008. The facility contains 7,456 meter-scale optics for amplification, beam steering, vacuum barriers, focusing, polarization rotation, and wavelength conversion. A multiphase program was put in place to increase the monthly optical manufacturing rate by up to 20x while simultaneously reducing cost by up to 3x through a sub-… more
Date: October 15, 2007
Creator: Stolz, C J
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
open access

Implementation of an interactive matching scheme for the Kapchinskij-Vladimirskij equations in the WARP code

Description: The WARP code is a robust electrostatic particle-in-cell simulation package used to model charged particle beams with strong space-charge forces. A fundamental operation associated with seeding detailed simulations of a beam transport channel is to generate initial conditions where the beam distribution is matched to the structure of a periodic focusing lattice. This is done by solving for periodic, matched solutions to a coupled set of ODEs called the Kapchinskij-Vladimirskij (KV) envelope equ… more
Date: April 15, 2008
Creator: Chilton, Sven H.
Item Type: Refine your search to only Thesis or Dissertation
Partner: UNT Libraries Government Documents Department
open access

Simulation of the Focusing DIRC Optics with Mathematica

Description: The Focusing DIRC is considered for the Barrel PID at a possible Super-B factory. To reduce sensitivity to background, it would be desirable to reduce a size of the present BaBar photon detector. One way to do it is to replace it with a focusing optics and use smaller photon detector pixels. We have simulated the focusing optics with simulation software based on a 3D calculation performed with the Mathematica program. The software does not use Optica package, instead, it uses its own 3D algorit… more
Date: February 15, 2010
Creator: Va'vra, J.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
open access

Varied line-space gratings and applications

Description: This paper presents a straightforward analytical and numerical method for the design of a specific type of varied line-space grating system. The mathematical development will assume plane or nearly-plane spherical gratings which are illuminated by convergent light, which covers many interesting cases for synchrotron radiation. The gratings discussed will have straight grooves whose spacing varies across the principal plane of the grating. Focal relationships and formulae for the optical grating… more
Date: July 15, 1991
Creator: McKinney, W.R.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
open access

Diagnostic beam line for a third generation storage ring

Description: A knowledge of the position, size, and stability of the source and the angle of emission of synchrotron radiation (SR) from the storage ring are essential for optimizing the operation of storage ring, insertion device and monochromators. Berkeley's Advanced Light Source (ALS) has a natural emittance of 3.4 {times} 10{sup {minus}9} m-rad, and has beam sizes {sigma}{sub h} and {sigma}{sub v} (assuming a 10% emittance ratio into the vertical direction) in bending magnet 1 (BM1) of 44 {mu}m and 83 … more
Date: May 15, 1991
Creator: Perera, R.C.C.; Melczer, M.E.; Warwick, A.; Jackson, A. & Kincaid, B.M.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
open access

Average neutralization and transverse stability in ISABELLE

Description: Clearing of electrons in the vicinity of the axis of a proton beam in the dipoles of a separated function AG-focusing structure is accomplished by transverse crossed-field drift due to the magnetic dipole field and a weak longitudinal electric field. This electric field is generated by potential differences caused by cross section variations of the beam due to variations of the ..beta..-functions and dispersion. The resulting radial drift brings the electrons into the off-axis region where they… more
Date: December 15, 1978
Creator: Herrera, J & Zotter, B
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
open access

Using a straightness reference in obtaining more accurate surface profiles from a Long Trace Profiler

Description: The Long Trace Profiler has found significant applications in measuring the surfaces of synchrotron optics. However, requirements of small slope errors at all spatial wavelengths of the synchrotron optics mandate more accurate slope measurements. A straightness reference for the Long Trace Profiler greatly increases the accuracy of the instrument. Methods of using the straightness reference by interpreting the sequential interference patterns are discussed and results of measurements are presen… more
Date: July 15, 1991
Creator: Irick, S. C.; McKinney, W. R.; Lunt, D. L. J. & Takacs, P. Z.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
open access

The Wavefront Control System for the National Ignition Facility

Description: The National Ignition Facility (NIF) requires that pulses from each of the 192 laser beams be positioned on target with an accuracy of 50 {micro}m rms. Beam quality must be sufficient to focus a total of 1.8 MJ of 0.351-{micro}m light into a 600-{micro}m-diameter volume. An optimally flat beam wavefront can achieve this pointing and focusing accuracy. The control system corrects wavefront aberrations by performing closed-loop compensation during laser alignment to correct for gas density variat… more
Date: October 15, 2001
Creator: Van Atta, L.; Perez, M.; Zacharias, R. & Rivera, W.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
open access

SLAC Cosmic Ray Telescope Facility

Description: SLAC does not have a test beam for the HEP detector development at present. We have therefore created a cosmic ray telescope (CRT) facility, which is presently being used to test the FDIRC prototype. We have used it in the past to debug this prototype with the original SLAC electronics before going to the ESA test beam. Presently, it is used to test a new waveform digitizing electronics developed by the University of Hawaii, and we are also planning to incorporate the new Orsay TDC/ADC electron… more
Date: February 15, 2010
Creator: Va'vra, J.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
open access

Reducing the losses of optical metamaterials

Description: The field of metamaterials is driven by fascinating and far-reaching theoretical visions, such as perfect lenses, invisibility cloaking, and enhanced optical nonlinearities. However, losses have become the major obstacle towards real world applications in the optical regime. Reducing the losses of optical metamaterials becomes necessary and extremely important. In this thesis, two approaches are taken to reduce the losses. One is to construct an indefinite medium. Indefinite media are materials… more
Date: December 15, 2010
Creator: Fang, Anan
Item Type: Refine your search to only Thesis or Dissertation
Partner: UNT Libraries Government Documents Department
open access

TIME-DEPENDENT PHASE SPACE MEASUREMENTS OF THE LONGITUDINALLY COMPRESSING BEAM IN NDCX-I

Description: The Neutralized Drift Compression Experiment (NDCXI) generates high intensity ion beams to explore Warm Dense Matter physics. A {approx}150 kV, {approx}500 ns modulating voltage pulse is applied to a {approx}300 kV, 5-10 {mu}s, 25 mA K+ ion beam across a single induction gap. The velocity modulated beam compresses longitudinally during ballistic transport along a space charge neutralizing plasma transport line, resulting in {approx}3A peak current with {approx}2-3 ns pulse durations (FWHM) at t… more
Date: March 15, 2011
Creator: LBNL; Lidia, S.M.; Bazouin, G. & Seidl, P.A.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
open access

Summary of Fermilab's Recycler Electron Cooler Operation and Studies

Description: Fermilab's Recycler ring was used as a storage ring for accumulation and subsequent manipulations of 8 GeV antiprotons destined for the Tevatron collider. To satisfy these missions, a unique electron cooling system was designed, developed and successfully implemented. The most important features that distinguish the Recycler cooler from other existing electron coolers are its relativistic energy, 4.3 MV combined with 0.1-0.5 A DC beam current, a weak continuous longitudinal magnetic field in th… more
Date: May 15, 2012
Creator: Prost, L. R. & Shemyakin, A.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
open access

Atomic data for the ITER Core Imaging X-ray Spectrometer

Description: The parameters of the ITER core plasmas will be measured using the Core Imaging X-ray Spectrometer (CIXS), a high-resolution crystal spectrometer focusing on the L-shell spectra of highly ionized tungsten atoms. In order to correctly infer the plasma properties accurate atomic data are required. Here, some aspects of the underlying physics are discussed using experimental data and theoretical predictions from modeling.
Date: June 15, 2012
Creator: Clementson, J.; Beiersdorfer, P.; Biedermann, C.; Bitter, M.; Delgado-Aparicio, L. F.; Graf, A. et al.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
open access

I. THE THEORY OF ABERRATIONS OF QUADRUPOLE FOCUSING ARRAYS. II. ION OPTICAL DESIGN OF HIGH QUALITY EXTRACTED SYNCHROTRON BEAMS WITH APPLICATION TO THE BEVATRON

Description: In Part One they formulate in a general way the problem of analyzing and evaluating the aberrations of quadrupole magnet beam systems, and of characterizing the shapes and other properties of the beam envelopes in the neighborhood of foci. They consider all aberrations, including those due to misalignments and faulty construction, through third order in small parameters, for quadrupole beam systems. One result of this study is the development of analytic and numerical techniques for treating th… more
Date: May 15, 1963
Creator: Meads Jr., Philip Francis
Item Type: Refine your search to only Thesis or Dissertation
Partner: UNT Libraries Government Documents Department
open access

Three-dimensional controlled-source electromagnetic and magnetotelluric joint inversion

Description: The growing use of the controlled-source electromagnetic method (CSEM) and magnetotellurics (MT) for exploration applications has been driving the development of data acquisition technologies, and three-dimensional (3-D) modeling and imaging techniques. However, targeting increasingly complex geological environments also further enhances the problems inherent in large-scale inversion, such as non-uniqueness and resolution issues. In this paper, we report on two techniques to mitigate these prob… more
Date: February 15, 2009
Creator: Commer, M. & Newman, G.A.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
open access

HEAVY QUARKS AT RHIC FROM PARTON TRANSPORT THEORY.

Description: There are several indications that an opaque partonic medium is created in energetic Au+Au collisions ({radical}s{sub NN} {approx} GeV/nucleon) at the Relativistic Heavy Ion Collider (RHIC). At the extreme densities of {approx} 10-100 times normal nuclear density reached even heavy-flavor hadrons are affected significantly. Heavy-quark observables are presented from the parton transport model MPC, focusing on the nuclear suppression pattern, azimuthal anisotropy (''elliptic flow''), and azimuth… more
Date: May 15, 2006
Creator: MOLNAR, D.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
open access

Tracking Multiple Topics for Finding Interesting Articles

Description: We introduce multiple topic tracking (MTT) for iScore to better recommend news articles for users with multiple interests and to address changes in user interests over time. As an extension of the basic Rocchio algorithm, traditional topic detection and tracking, and single-pass clustering, MTT maintains multiple interest profiles to identify interesting articles for a specific user given user-feedback. Focusing on only interesting topics enables iScore to discard useless profiles to address ch… more
Date: February 15, 2007
Creator: Pon, R K; Cardenas, A F; Buttler, D J & Critchlow, T J
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
open access

Design Issues for the Superconducting Magnet that Goes Around theLiquid Hydrogen Absorber for the Muon Ionization Cooling Experiment(MICE)

Description: This report describes the design issues that are associated with a superconducting focusing solenoid that goes around a liquid hydrogen absorber for the Muon Ionization Cooling Experiment (MICE) proposed for the Rutherford Appleton Laboratory. The solenoid consists of two superconducting coils that may operated at the same polarity or at opposite polarities. As a result, the coils and their support structure must be designed to carry a 360-ton inter-coil force that is forcing the coils apart al… more
Date: June 15, 2004
Creator: Barr, G.; Cobb, J. H.; Green, M. A.; Lau, W.; R. S., Senanayake; Yang, S. Q. et al.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
open access

Simulating Electron Clouds in High-Current Ion Accelerators with Solenoid Focusing

Description: Contamination from electrons is a concern for the solenoid-focused ion accelerators being developed for experiments in high-energy-density physics (HEDP). These electrons are produced directly by beam ions hitting lattice elements and intercepting diagnostics, or indirectly by ionization of desorbed neutral gas, and they are believed responsible for time dependence of the beam radius, emittance, and focal distance seen on the Solenoid Transport Experiment (STX) at Lawrence Berkeley National Lab… more
Date: August 15, 2006
Creator: Sharp, W.; Grote, D.; Cohen, R.; Friedman, A.; Vay, J.; Seidl, P. et al.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
open access

Focusing solenoids for the MICE cooling channel

Description: This report describes a design for focusing solenoids for the low beta sections for the proposed Muon Ionization Cooling Experiment (MICE). There are three focusing solenoid pairs that will be around the muon absorbers for MICE. The two solenoid coils have an inside diameter of 510 mm, a length of 180 mm, and a thickness of 100 mm. A distance of 260 mm separates the two coils in the pair. The coils are designed to operate at opposite polarity, in order to create a gradient field in the low beta… more
Date: September 15, 2003
Creator: Green, M.A.; Baynham, E.; Barr, G.; Lau, W.; Rochford, J.H. & Yang, S.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
open access

A Proposed Fast Luminosity Feedback for the Super-B Accelerator

Description: We present a possible design for a fast luminosity feedback for the SuperB Interaction Point (IP). The design is an extension of the fast luminosity feedback installed on the PEP-II accelerator. During the last two runs of PEP-II and BaBar (2007-2008), we had an improved luminosity feedback system that was able to maintain peak luminosity with faster correction speed than the previous system. The new system utilized fast dither coils on the High-Energy Beam (HEB) to independently dither the x p… more
Date: May 15, 2009
Creator: Bertsche, Kirk; Field, R.Clive; Fisher, Alan; Sullivan, Michael & Drago, Alessandro
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
open access

Geothermal Reservoir Dynamics - TOUGHREACT

Description: This project has been active for several years and has focused on developing, enhancing and applying mathematical modeling capabilities for fractured geothermal systems. The emphasis of our work has recently shifted towards enhanced geothermal systems (EGS) and hot dry rock (HDR), and FY05 is the first year that the DOE-AOP actually lists this project under Enhanced Geothermal Systems. Our overall purpose is to develop new engineering tools and a better understanding of the coupling between flu… more
Date: March 15, 2005
Creator: Pruess, Karsten; Xu, Tianfu; Shan, Chao; Zhang, Yingqi; Wu, Yu-Shu; Sonnenthal, Eric et al.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
open access

Particle Simulations of a Long Pulse Electron Beam in a Bend

Description: Advanced x-ray radiography machines require that multiple electron beam pulses be delivered to x-ray converter targets over several lines of sight. This can be accomplished using a single accelerator by using a fast kicker to deliver the electron beam pulses to several beamlines. This type of radiography machine requires transport lines with several large achromatic bends in the individual transport lines. To maintain a small spot size and a large dose for an x-ray pulse created at the converte… more
Date: August 15, 2000
Creator: Poole, B. R. & Chen, Y. J.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
Back to Top of Screen