A Model Study of Transverse Mode Coupling Instability at National Synchrotron Light Source-II (Nsls-II). (open access)

A Model Study of Transverse Mode Coupling Instability at National Synchrotron Light Source-II (Nsls-II).

The vertical impedances of the preliminary designs of National Synchrotron Light Source II (NSLS-II) Mini Gap Undulators (MGU) are calculated by means of GdfidL code. The Transverse Mode Coupling Instability (TMCI) thresholds corresponding to these impedances are estimated using an analytically solvable model.
Date: May 15, 2005
Creator: Blednykh, A. & Wang, J. M.
Object Type: Article
System: The UNT Digital Library
RESEARCH AND DEVELOPMENT OF A VARIABLE POLARIZATION SUPERCONDUCTING UNDULATOR AT THE NSLS. (open access)

RESEARCH AND DEVELOPMENT OF A VARIABLE POLARIZATION SUPERCONDUCTING UNDULATOR AT THE NSLS.

In this paper a new concept for a planar, superconductive, variable polarization undulator (VPU) is presented. Advantage of this design include: (1) electrical tunability for both right and left circular and elliptical, as well as linear vertical or horizontal, (2) it requires no compensation of unwanted vertical field component and (3) used only simple windings of superconductive wire in an interlaced pattern. The construction of the device is described and compared with a permanent magnet VPU with the same gap and period, as well as with previously published concepts.
Date: May 15, 2005
Creator: CHOUHAN, S.; HARDER, D.; RAKOWSKY, G. & AL., ET
Object Type: Article
System: The UNT Digital Library
Evaluating the Effects of Aging on Electronic Instrument and Control Circuit Boards and Components in Nuclear Power Plants (open access)

Evaluating the Effects of Aging on Electronic Instrument and Control Circuit Boards and Components in Nuclear Power Plants

The report describes potentially useful techniques for monitoring the aging of I&C boards. The techniques have been grouped into: periodic testing, reliability modeling, resistance measures, signal comparison, eternal measures, and internal measures, each representing distinct theoretical approaches to detection and evaluation.
Date: May 15, 2005
Creator: Hannaman, G. William & Wilkinson, C. Dan
Object Type: Report
System: The UNT Digital Library
An Accelerator Control Middle Layer Using MATLAB (open access)

An Accelerator Control Middle Layer Using MATLAB

Matlab is an interpretive programming language originally developed for convenient use with the LINPACK and EISPACK libraries. Matlab is appealing for accelerator physics because it is matrix-oriented, provides an active workspace for system variables, powerful graphics capabilities, built-in math libraries, and platform independence. A number of accelerator software toolboxes have been written in Matlab -- the Accelerator Toolbox (AT) for model-based machine simulations, LOCO for on-line model calibration, and Matlab Channel Access (MCA) to connect with EPICS. The function of the MATLAB ''MiddleLayer'' is to provide a scripting language for machine simulations and on-line control, including non-EPICS based control systems. The MiddleLayer has simplified and streamlined development of high-level applications including configuration control, energy ramp, orbit correction, photon beam steering, ID compensation, beam-based alignment, tune correction and response matrix measurement. The database-driven Middle Layer software is largely machine-independent and easy to port. Six accelerators presently use the software package with more scheduled to come on line soon.
Date: May 15, 2005
Creator: Portmann, Gregory J.; Corbett, Jeff & Terebilo, Andrei
Object Type: Article
System: The UNT Digital Library
Coal Combustion Products Extension Program Quarterly Report (open access)

Coal Combustion Products Extension Program Quarterly Report

The primary objective of the CCP Extension Program is to promote the responsible uses of Ohio CCPs that are technically sound, environmentally safe, and commercially competitive. A secondary objective is to assist other CCP generating states (particularly neighboring states) in establishing CCP use programs within their states. The goal of the CCP extension program at OSU is to work with CCP stakeholders to increase the overall CCP state utilization rate to more than 30% by the year 2005. The program aims to increase FGD utilization for Ohio to more than 20% by the year 2005. The increased utilization rates are expected to be achieved through increased use of CCPs for highway, mine reclamation, agricultural, manufacturing, and other civil engineering uses. In order to accomplish these objectives and goals, the highly successful CCP pilot extension program previously in place at the university has been expanded and adopted by the university as a part of its outreach and engagement mission. The extension program is an innovative technology transfer program with multiple sponsors. The program is a collaborative effort between The Ohio State University (College of Engineering and University Extension Service), United States Department of Energy's National Energy Technology Laboratory, Ohio Department of …
Date: May 15, 2005
Creator: Butalia, Tarunjit S. & Wolfe, William E.
Object Type: Report
System: The UNT Digital Library
Effects of Birefringence and Nonlinearity on Optical Pulse Propagation in New Types of Optical Fibers (open access)

Effects of Birefringence and Nonlinearity on Optical Pulse Propagation in New Types of Optical Fibers

The purpose of this grant was to allow us to complete work that we had already begun on spun optical fibers and to begin studies of holey and photonic crystal optical fibers. The work on spun optical fibers was completed with great success. It led to several publications in collaboration with our co-workers at the Universita di Padova, and the student who carried out this work received a major award from the Universita di Padova. The work on holey and photonic crystal fibers has proceeded more slowly, but, in collaboration with Korean co-workers at the Gwangju Institute of Science and Technology, we have developed three different computational models that allow us to calculate the modes of these fibers: a Galerkin model, a plane wave model, and a multipole model. We have applied these models to the study of mode coupling in periodic gratings. In collaboration with scientists at the Naval Research Laboratory, we have also applied these models to the study of pulse compression in tapered fibers and the development of nonlinear fibers that are capable of handling large powers in high-index and chalcogenide glasses. European and Asian countries have made large investments in the development of these new glass …
Date: May 15, 2005
Creator: Menyuk, Curtis R. & Carter, Gary M.
Object Type: Report
System: The UNT Digital Library
HADRONIC SCATTERING IN THE COLOR GLASS CONDENSATE. (open access)

HADRONIC SCATTERING IN THE COLOR GLASS CONDENSATE.

Multi-particle production in QCD is dominated by higher twist contributions. The operator product expansion is not very effective here because the number of relevant operators grow rapidly with increasing twist. The Color Glass Condensate (CGC) provides a framework in QCD to systematically discuss ''classical'' (multiple scattering) and ''quantum'' evolution (shadowing) effects in multi-particle production. The apparently insuperable problem of nucleus-nucleus scattering in QCD simplifies greatly in the CGC. A few examples are discussed with emphasis on open problems.
Date: May 15, 2005
Creator: Venugopalan, R.
Object Type: Article
System: The UNT Digital Library
Harmonic Cavity Performance for NSLS-II (open access)

Harmonic Cavity Performance for NSLS-II

NSLS-II is a 3 GeV ultra-high brightness storage ring planned to succeed the present NSLS rings at BNL. Ultralow emittance combined with short bunch length means that it is critical to minimize the effects of Touschek scattering and coherent instabilities. Improved lifetime and stability can be achieved by including a third-harmonic RF cavity in the baseline design. This paper describes the required harmonic RF parameters and the expected system performance.
Date: May 15, 2005
Creator: Blednykh, A.; Krinsky, S.; Podobedov, B.; Rose, J.; Towne, N. & Wang, J. M.
Object Type: Article
System: The UNT Digital Library
DYNAMIC APERTURE OPTIMIZATION FOR LOW EMITTANCE LIGHT SOURCES. (open access)

DYNAMIC APERTURE OPTIMIZATION FOR LOW EMITTANCE LIGHT SOURCES.

State of the art low emittance light source lattices, require small bend angle dipole magnets and strong quadrupoles. This in turn creates large chromaticity and small value of dispersion in the lattice. To counter the high linear chromaticity, strong sextupoles are required which limit the dynamic aperture. Traditional methods for expanding the dynamic aperture use harmonic sextupoles to counter the tune shift with amplitude. This has been successful up to now, but is non-deterministic and limited as the sextupole strength increases, driving higher order nonlinearities. We have taken a different approach that makes use of the tune flexibility of a TBA lattice to minimize the lowest order nonlinearities, freeing the harmonic sextupoles to counter the higher order nonlinearities. This procedure is being used to improve the nonlinear dynamics of the NSLS-II lattice.
Date: May 15, 2005
Creator: KRAMER, S. & BENGTSSON, J.
Object Type: Article
System: The UNT Digital Library
CONTROL OF DYNAMIC APERTURE FOR SYNCHROTRON LIGHT SOURCES. (open access)

CONTROL OF DYNAMIC APERTURE FOR SYNCHROTRON LIGHT SOURCES.

A summary of how modern analytical and numerical techniques enable one to construct a realistic model of state-of-the-art synchrotron light sources is provided. The effects of engineering tolerances and radiation are included in a self-consistent manner. An approach for utilizing these tools to develop an effective strategy for the design and control of the dynamic aperture for such dynamical systems is also outlined.
Date: May 15, 2005
Creator: BENGTSSON, J.
Object Type: Article
System: The UNT Digital Library
PERFORMANCE CALCULATION ON ORBIT FEEDBACK FOR NSLS II. (open access)

PERFORMANCE CALCULATION ON ORBIT FEEDBACK FOR NSLS II.

We discuss the preliminary calculation on the performance of closed orbit feedback system for NSLSII, its relation to the requirement on BPM, floor and girder stability, power supply stability etc.
Date: May 15, 2005
Creator: YU, LI-HUA
Object Type: Article
System: The UNT Digital Library
Impedance of Finite Length Resistor (open access)

Impedance of Finite Length Resistor

We determine the impedance of a cylindrical metal tube (resistor) of radius a, length g, and conductivity {sigma}, attached at each end to perfect conductors of semi-infinite length. Our main interest is in the asymptotic behavior of the impedance at high frequency, k >> 1/a. In the equilibrium regime, , the impedance per unit length is accurately described by the well-known result for an infinite length tube with conductivity {sigma}. In the transient regime, ka{sup 2} >> g, we derive analytic expressions for the impedance and wakefield.
Date: May 15, 2005
Creator: Krinsky, S.; Podobedov, B. & Gluckstern, R. L.
Object Type: Article
System: The UNT Digital Library