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in subjects: "Harmonics"

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HVDC-AC system interaction from AC harmonics. Volume 1. Harmonic impedance calculations. Final report

Improved methods are needed to characterize ac system harmonic behavior for ac filter design for HVDC systems. The purpose of this General Electric Company RP1138 research is to evaluate the present filter design practice and to investigate methods for calculating system harmonic impedances. An overview of ac filter design for HVDC systems and a survey of literature related to filter design have been performed. Two methods for calculating system harmonic impedances have been investigated. In th… more

Date: September 1, 1982

Creator: Breuer, G D; Chow, J H; Lindh, C B; Miller, N W; Numrich, F H; Price, W W et al.

Item Type: Report

Partner: UNT Libraries Government Documents Department

open access

Estimates of post-acceleration longitudinal bunch compression

A simple analytic method is developed, based on physical approximations, for treating transient implosive longitudinal compression of bunches of heavy ions in an accelerator system for ignition of inertial-confinement fusion pellet targets. Parametric dependences of attainable compressions and of beam path lengths and times during compression are indicated for ramped pulsed-gap lines, rf systems in storage and accumulator rings, and composite systems, including sections of free drift. It appear… more

Date: November 25, 1977

Creator: Judd, D.L.

Item Type: Article

Partner: UNT Libraries Government Documents Department

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On bunch lengthening using the fourth harmonic cavity in the NSLS VUV ring

It has been suggested that the phase of the beam excited voltage in the harmonic cavity can be controlled by detuning its resonant frequency from the beam current harmonic. Unfortunately the detuning needed to flatten the acceleration waveform also corresponds to the region of Robinson instability for the harmonic cavity. Therefore, lengthening the bunch may be followed by large amplitude synchrotron oscillation of the bunch center of mass. Bunch lengthening is discussed in this note from sever… more

Date: February 1, 1988

Creator: Wachtel, J.M.

Item Type: Report

Partner: UNT Libraries Government Documents Department

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Analytic representation of three-dimensional stellarator field

The stellarator configuration can be greatly simplified when toroidal harmonics are introduced. The toroidal function satisfies Laplace's equation and together with toroidal field and vertical field, a small-aspect-ratio stellarator can be constructed with an aspect ratio as low as 3.6. This functional presentation suggests a very fast computation of particle orbits and magnetic configuration.

Date: September 1, 1983

Creator: Yoshikawa, S.

Item Type: Article

Partner: UNT Libraries Government Documents Department

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3D field harmonics

We have developed an harmonic representation for the three dimensional field components within the windings of accelerator magnets. The form by which the field is presented is suitable for interfacing with other codes that make use of the 3D field components (particle tracking and stability). The field components can be calculated with high precision and reduced cup time at any location (r,{theta},z) inside the magnet bore. The same conductor geometry which is used to simulate line currents is … more

Date: March 30, 1991

Creator: Caspi, S.; Helm, M. & Laslett, L.J.

Item Type: Report

Partner: UNT Libraries Government Documents Department

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Polarized Proton Acceleration at the Brookhaven AGS

At the conclusion of polarized proton commissioning in February 1986, protons with an average polarization of 45%, momentum of 21.7 GeV/c, and intensity of 2 x 10/sup 10/ protons per pulse, were extracted to an external polarimeter at the Brookhaven AGS. In order to maintain this polarization, five intrinsic and nearly forty imperfection depolarizing resonances had to be corrected. An apparent interaction between imperfection and intrinsic resonances occurring at very nearly the same energy was… more

Date: January 1, 1986

Creator: Ahrens, L. A.

Item Type: Article

Partner: UNT Libraries Government Documents Department

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Correcting the AGS depolarizing resonances

For the 1986 AGS run, the technique of correcting an imperfection resonance using a beat harmonic instead of the direct harmonic was applied and found to be useful in achieving a 22 GeV/c polarized beam. Both conventional and modified techniques are explained. (LEW)

Date: January 1, 1986

Creator: Ratner, L. G.

Item Type: Article

Partner: UNT Libraries Government Documents Department

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Development of a free-electron laser user facility for the extreme ultraviolet

A free-electron laser user facility for scientific experimentation in the extreme ultraviolet is being developed at Los Alamos. A series of laser oscillators and amplifiers, driven by a single, rf linear accelerator, will generate broadly tunable, picosecond-pulse, coherent radiation from 1 nm to 400 nm. The design and output parameters of this facility are described, comparison with synchrotron radiation sources is made, and recent progress in developing the three primary components (electron … more

Date: January 1, 1987

Creator: Newnam, B.E.

Item Type: Article

Partner: UNT Libraries Government Documents Department

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Theory of the beta function shift due to linear coupling

This paper presents analytical perturbation theory results for {beta}{sub 1}, {beta}{sub 2}, the beta functions in the presence of linear coupling.

Date: January 1, 1992

Creator: Parzen, G.

Item Type: Article

Partner: UNT Libraries Government Documents Department

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Magnetic measurements of the correction and adjustment magnets of the main ring

Correction magnets correct the field imperfections and alignment errors of the main quadrupole and bend magnets. For reducing and controlling chromaticity there are 186 sextupoles and 78 octupoles, while for suppressing various resonances there are 12 normal and 18 skew sextupoles and 24 normal and 19 skew quadrupoles. Beam positions are individually controlled by 108 horizontal and 108 skew dipoles. This report includes results of the all Main Ring correction and adjustment magnet harmonic mea… more

Date: July 1, 1986

Creator: Trbojevic, D.

Item Type: Article

Partner: UNT Libraries Government Documents Department

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Mapping from rectangular to harmonic representation

An algorithm is developed to determine the Fourier harmonics representing the level contours of a scalar function given on a rectangular grid. This method is applied to the problem of computing the flux coordinates and flux surface average needed for 1-1/2-D transport codes and MHD stability codes from an equilibrium flux function given on a rectangular grid.

Date: August 1, 1986

Creator: Schneider, W. & Bateman, G.

Item Type: Report

Partner: UNT Libraries Government Documents Department

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Beam bunching in a final storage ring

A calculation is presented for the final bunching of a particle beam in a synchrotron or storage ring. The voltage per turn, the harmonic number, and the bunching time are obtained. (PMA)

Date: November 18, 1977

Creator: Lambertson, G.R.

Item Type: Article

Partner: UNT Libraries Government Documents Department

open access

The beam dynamics study in a compact synchrotron

A new computer code has been developed for compact synchrotron design. Based on a numerical integration of the exact equations of motion, the systematic beam dynamics study is carried out, with either computed or measured magnet field including magnet edges. Significant discrepancies of machine parameters reveal some unique features of the beam dynamics in small synchrotrons. Interactive procedures between the beam dynamics predictions on the one hand and the magnet design on the other are then… more

Date: January 1, 1991

Creator: Huang, Yunxiang & Ohunuma, Shorokou (Houston Univ., TX (United States). Dept. of Physics Texas Accelerator Center, The Woodlands, TX (United States))

Item Type: Article

Partner: UNT Libraries Government Documents Department

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Theory of the tune shift due to linear coupling

The presence of skew quadrupole fields will linearly couple the x and y motions. The x and y motion can then be written as the sum of two normal modes which have the tunes {nu}{sub 1},{nu}{sub 2}, in the absence of the skew quadrupole fields. New beta functions, {Beta}{sub 1} and {Beta}{sub 2}, can be defined which are the beta functions of the normal modes and which are different from {Beta}{sub x} and {Beta}{sub y}, the beta functions of the unperturbed accelerator. This paper presents analyt… more

Date: July 1, 1991

Creator: Parzen, G.

Item Type: Report

Partner: UNT Libraries Government Documents Department

open access

Optical characteristics of super-radiant harmonic radiation from a FEL and optical klystron. 3D model

In free-electron sources of coherent light, bunching of the electrons allows the super-radiant production of coherent harmonic radiation, up to substantially high harmonic numbers. This paper presents a fully three dimensional model formulation for evaluating coherent harmonic radiation from a free-electron laser or optical klystron. The radiated electromagnetic field is expanded in terms of a set of orthonogonal free-space modes. Expansion coefficients can be evaluated once a generalized form … more

Date: January 1, 1986

Creator: Gover, A.; Luccio, A.; Friedman, A. & Fauchet, A.M.

Item Type: Article

Partner: UNT Libraries Government Documents Department

open access

Calculation of eddy-currents induced in a compact synchrotron superconducting magnet structure during a current ramp

Under DARPA sponsorship, a compact Superconducting X-Ray Light Source (SXSL) is being designed and built by the Brookhaven National Laboratory (BNL) with industry participation from Grumman Corporation and General Dynamics. The SXLS machine employs two 180{degrees} curved 4 telsa superconducting dipole magnets. These magnets are required to produce a dipole field for bending the beam but at the same time they must produce finite amounts of higher multipoles which are required for conditioning t… more

Date: January 1, 1991

Creator: Kalsi, S. (Grumman Corp., Bethpage, NY (USA). Space and Electronics Systems Div.) & Heese, R. (Brookhaven National Lab., Upton, NY (USA))

Item Type: Article

Partner: UNT Libraries Government Documents Department

open access

Harmonic analysis of Fermilab main ring quadrupoles

The Main Ring Quadrupoles have been used in the Fermilab Main Ring and will be utilized in the proposed Fermilab Main Injector. Utilizing a rotating coil harmonic measurement system, a sample of more than 35 Fermilab Main Ring Quadrupoles have been measured. The asymmetric design of these magnets provides many easily measured harmonic coefficients. Results for harmonic coefficients at various excitation levels are presented. 5 refs., 3 figs., 1 tab.

Date: May 1, 1991

Creator: Brown, B. C.; Mazur, P. O.; Ostiguy, J. F.; Pruss, S. M. & Turkot, F.

Item Type: Article

Partner: UNT Libraries Government Documents Department

open access

Magnetic field measurements of Fermilab/General Dynamics built full scale SSC collider dipole magnets

This paper presents preliminary results of magnetic field measurements made on a series of 50 mm aperture 15 m long SSC collider dipole magnets designed and manufactured at Fermi National Accelerator Laboratory (Fermilab) for use in the Superconducting Super Collider Laboratory (SSCL) Accelerator System String Test. The magnets were assembled by Fermilab and General Dynamics personnel, and were tested at the Magnet Test Facility (MTF) at Fermilab. Measurements of the dipole field angle, dipole … more

Date: April 1, 1992

Creator: Delchamps, S.; Bleadon, M.; Bossert, R.; Carson, J.; Gourlay, S.; Hanft, R. et al.

Item Type: Article

Partner: UNT Libraries Government Documents Department

open access

One gigasample per second transient recorder: a performance demonstration

The performance demonstrated by a one gigasample per second (1 Gs/s) transient recorder currently in advanced development portends an important new instrument for recording single transient data. A Charge-Coupled Device (CCD) is used to sample a continuous analog signal. Samples acquired at the full sampling rate (1 Gs/s) are temporarily stored in the CCD, then read out at a slow rate (e.g., 250 Ks/s) into a conventional analog-to-digital converter prior to storage in nonvolatile, digital memor… more

Date: January 1, 1982

Creator: Linnenbrink, T. E.; Gradl, D. A.; Ritt, D. M.; DeWitte, G. J. & Hutton, J. D.

Item Type: Article

Partner: UNT Libraries Government Documents Department

open access

Longitudinal dynamics in storage rings

The single-particle equations of motion are derived for charged particles in a storage ring. Longitudinal space charge is included in the potential assuming an infinitely conducting circular beam pipe with a distributed inductance. The framework uses Hamilton's equations with the canonical variables phi and W. The Twiss parameters for longitudinal motion are also defined for the small amplitude synchrotron oscillations. The space-charge Hamiltonian is calculated for both parabolic bunches and '… more

Date: January 1, 1986

Creator: Colton, E. P.

Item Type: Article

Partner: UNT Libraries Government Documents Department

open access

Electrical characterization of rf plasmas

Radio-frequency (rf) electrical sources are commonly used to generate plasmas for processing of industrial materials and for related experimental work. Published descriptions of such plasmas usually include generator-power measurements, and occasionally include plasma dc-bias measurements. One or both of these quantitites are also used in industrial feedback ccontrol systems for setpoint regulation. Recent work at Sandia an elsewhere with an experimental rf discharge device (the GEC RF Referenc… more

Date: August 1, 1991

Creator: Miller, P.A.

Item Type: Article

Partner: UNT Libraries Government Documents Department

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Theory of the tune shift due to linear coupling

This paper presents analytical perturbation theory results for {nu}{sub 1}, {nu}{sub 2}, the tune in tune presence of linear coupling.

Date: January 1, 1992

Creator: Parzen, G.

Item Type: Article

Partner: UNT Libraries Government Documents Department

open access

Quadrupole magnet for the APS (Advanced Photon Source) storage ring

An asymmetric core geometry has been selected for the quadrupole magnets in the storage ring of the Advanced Photon Source (APS) in order to accommodate the vacuum chamber and photon beam pipes. The requirements of the position beam make it necessary that the magnet be able to produce a field gradient of 20-T/m with high accuracy. The design for this magnet has been fully developed in preparation for the construction of a prototype. Some unique features included in the design are described. Des… more

Date: January 1, 1989

Creator: Thompson, K. M.; Kim, S. H.; Lari, R. J.; Turner, L.R. (Argonne National Lab., IL (USA); Vector Fields Ltd., Aurora, IL (USA) & Argonne National Lab., IL (USA))

Item Type: Article

Partner: UNT Libraries Government Documents Department

open access

New harmonic materials: index engineering. Thin-thick quadrature frequency conversion

The quadrature conversion scheme is a method of generating the second harmonic. The scheme, which uses two crystals in series, has several advantages over single-crystal or other two crystal schemes. The most important is that it is capable of high conversion efficiency over a large dynamic range of drive intensity and detuning angle. Consider a pair of KDP crystals cut for type-II phase matching. In the quadrature scheme, the optic axes of the crystals are arranged so that the plans containing… more

Date: February 7, 1985

Creator: Eimerl, D.

Item Type: Article

Partner: UNT Libraries Government Documents Department