35 Matching Results

Search Results

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

Ideal ballooning stability near an equilibrium magnetic island

Description: The stability properties of ideal ballooning modes on toroidal flux surfaces near a quasistatic magnetic island is examined. On these surfaces, magnetic field-line trajectories tend to bunch on that part of the magnetic surface closet to the X-point of the magnetic island. Because of this preferential bunching, the stabilizing effect of field-line bending due to magnetic shear can be reduced. Eigenfunctions localized in helical angle near the X-point and in poloidal angle on the bad curvature s… more
Date: March 1, 1992
Creator: Hegna, C. C. & Callen, J. D.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
open access

Ripple bundle divertor for tokamaks

Description: The bundle divertor, designed for density and impurity control, has been successfully applied on the DITE tokamak. In this application it is subject to high stresses and is restricted to short pulses and low toroidal fields. A new version is made possible by fitting the vacuum vessel close to the toroidal coils. This allows the plasma to exist in the outer regions of higher toroidal field ripple. This ripple bundle divertor should operate at lower stresses and for longer pulses at higher magnet… more
Date: March 1, 1978
Creator: Sheffield, J. & Dory, R.A.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
open access

Longitudinal capture in the radio-frequency-quadrupole structure

Description: The radio-frequency-quadrupole (RFQ) linac structure not only can attain easily transverse focusing in the low-beta region, but also can obtain very high capture efficiency because of its low beta-lambda and low-particle rigidity. An optimization study of the zero space-charge longitudinal capture in an RFQ linac that yields configurations with large capture efficiency is described.
Date: March 1, 1980
Creator: Inagaki, S.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
open access

Determination of plasma shape from poloidal field measurements on ISX-B

Description: The ISX-B tokamak has a poloidal coil system designed to produce circular, elliptical, and D-shaped plasmas. Plasma shape and low-order multipole moments of the plasma current distribution are determined from experimental measurements of B/sub Z/, B/sub R/, and/or psi around the periphery of the vacuum chamber. The experimental arrangement and method of analysis of results, using a least squares method to fit the data points to a finite current filament model, are described in this report. Plas… more
Date: March 1, 1980
Creator: Swain, D. W.; Bates, S.; Neilson, G. H. & Peng, Y. K. M.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
open access

High-power ion-cyclotron heating on the levitated octupole

Description: Experiments are underway in the Wisconsin Levitated Toroidal Octupole to create hot, dense plasmas to facilitate the study of ..beta.. limits and related phenomena such as Pfirsch-Schlueter and bootstrap currents. The question of ballooning mode instability limits on ..beta.. = 8 ..pi..nk(T/sub i/+T/sub e/)/B/sup 2/ is of general importance for all toroidal systems, and ICRF heating should permit study of high ..beta.. plasmas with lower collisionality and smaller gyroradii than those of the hi… more
Date: March 1, 1982
Creator: Dexter, R.N.; Fortgang, C.M.; Prager, S.C.; Sprott, J.C.; Strait, E.J. & Twichell, J.C.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
open access

OCLATOR II (One Coil Low Aspect Toroidal Reactor)

Description: Following the general description of OCLATOR (I), more thoughts are presented here. It suggests that the blanket may not be changed for the plant lifetime. Also miniaturization of OCLATOR is discussed, especially if the ripple turbulence could be improved upon the presently set limit which applies to a large number of ripples.
Date: March 1, 1980
Creator: Yoshikawa, S.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
open access

Analytical expressions for the smear due to nonlinear multipoles

Description: An analytical derivation of the horizontal smear due to sextupoles and octupoles is presented. A generalized expression for the horizontal smear due to all multipoles is derived. A two degree of freedom calculation yields the smear due to sextupoles and octupoles. Experimental observations of the smear induced by special sextupoles have been made at the Fermilab Tevatron and our calculations agree very well with the data over a wide range of conditions. The smear due to random and systematic mu… more
Date: March 1, 1989
Creator: Merminga, Nikolitsa & Ng, King-Yuen
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
open access

Method and apparatus for the formation of a spheromak plasma

Description: An inductive method and apparatus for forming detached spheromak plasma using a thin-walled metal toroidal ring are described that uses external current leads and internal poloidal and toroidal field coils located inside a vacuum chamber filled with low density hydrogen gas and an external axial field generating coil. The presence of a current in the poloidal field coils, and an externally generated axial field sets up the initial poloidal field configuration in which the field is strongest tow… more
Date: March 24, 1981
Creator: Jardin, S. C.; Yamada, M.; Furth, H. P. & Okabayashi, M.
Item Type: Refine your search to only Patent
Partner: UNT Libraries Government Documents Department
open access

Effects of pressure anisotropy on plasma transport

Description: In a recent paper a new set of generalized two-field equations is derived which describes plasma transport along the field lines of a space and time dependent magnetic field. These equations are valid for collisional to weakly collisional plasmas; they reduce to the conventional fluid equations of Braginskii for highly collisional plasmas. An important feature of these equations is that the anisotropy in the ion pressure is explicitly included. In this paper, these generalized transport equatio… more
Date: March 1, 1986
Creator: Zawaideh, E.; Najmabadi, F. & Conn, R.W.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
open access

Insertion devices for the Advanced Light Source at LBL

Description: The Advanced Light Source (ALS) at the Lawrence Berkeley Laboratory will be the first of the new generation of dedicated synchrotron light sources to be put into operation. Specially designed insertion devices will be required to realize the high brightness photon beams made possible by the low emittance of the electron beam. The complement of insertion devices on the ALS will include undulators with periods as short as 3.9 cm and one or more high field wigglers. The first device to be designed… more
Date: March 1, 1989
Creator: Hassenzahl, W.; Chin, J.; Halbach, K.; Hoyer, E.; Humphries, D.; Kincaid, B. et al.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
open access

MIG: MCNP input generator for EFFI magnet geometries

Description: A computer code, MIG, has been developed to interface the magnet design and the three-dimensional Monte Carlo code MCNP to perform neutronics design analyses. MIG prepares all the required MCNP cells and surfaces to simulate the magnets described in EFFI input. Extra zones with different materials could be added to envelop or divide the winding packs of the magnets. Examples of the input and output of MIG used by MCNP are given to illustrate the different capabilities of MIG.
Date: March 1, 1985
Creator: Attaya, H. & Gohar, Y.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
open access

Numerical determination of the magnetic field line Hamiltonian

Description: The structure of a magnetic field is determined by a one-degree of freedom, time-dependent Hamiltonian. This Hamiltonian is evaluated for a given field in a perturbed action-angle form. The location and the size of magnetic islands in the given field are determined from Hamiltonian perturbation theory and from an ordinary Poincare plot of the field line trajectories.
Date: March 1, 1986
Creator: Kuo-Petravic, G. & Boozer, A. H.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
open access

Progress toward fusion energy

Description: This paper summarizes the basis for the present optimism in the magnetic fusion program, and describes some of the remaining tasks leading to a demonstration power reactor and the primary technologies necessary for that endeavor.
Date: March 11, 1981
Creator: Thomassen, K.I.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
open access

Approximate model for toroidal force balance in the high-beta stellarator

Description: A simple model for estimating the body force acting on a diffuse plasma confined in a three-dimensional, high-beta stellarator geometry is given. The equilibrium is treated by an asymptotic expansion about a straight theta pinch with diffuse, circular cross section. The expansion parameter delta is the strength of the applied helical fields. This expansion leads to an inconsistent set of equations for the equilibrium in second order. Nevertheless, by averaging the equilibrium equations over the… more
Date: March 1, 1979
Creator: Barnes, D. C.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
open access

The magnet lattice of the LBL 1-2 GeV Synchrotron Radiation Source

Description: This paper describes the magnet chosen for the LBL 1-2 GeV Synchrotron Radiation Source. The structure has a circumference of 196.8 m, with 12 dispersion free straight sections that can accommodate insertion devices up to 5 m long. The achromatic arcs that connect these straight sections feature combined function (gradient) bending magnets. Utilization of three such magnets in the so-called three-bend-achromat (TBA) arrangement, has several beneficial effects: (1) it reduces the amplitude of th… more
Date: March 1, 1987
Creator: Jackson, A.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
open access

Bistable equilibrium of tokamak and its application to magnetic pumping

Description: It has been experimentally demonstrated in the ATC device that, with appropriate adjustments of the external magnetic circuitry, the tokamak plasma may be stable for two different major radii. The dynamics of transition between the two equilibria involves a faster compression and expansion of the plasma, than is practical in the monostable case; thus may be useful in the Artsimovich-Furth-Ellis axisymmetric magnetic pumping scheme.
Date: March 1, 1977
Creator: Hsuan, H. & Bol, K.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
open access

Octupole anchor for tandem mirrors

Description: The octupole anchor is a very promising alternative to the usual quadrupole designs. The most critical unsolved problem is stabilization of the trapped particle mode. The anchor magnetic field is low because MHD stabilization is by hot electrons, thus permitting relatively small magnet currents and conductor cross sections. Increasing the field to a sufficient level to permit operation of the thermal barrier and electrostatic plug required for trapped particle mode stabilization would require m… more
Date: March 21, 1984
Creator: Hopper, E.B. Jr.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
open access

Magnetic field line Hamiltonian

Description: The magnetic field line Hamiltonian and the associated canonical form for the magnetic field are important concepts both for understanding toroidal plasma physics and for practical calculations. A number of important properties of the canonical or Hamiltonian representation are derived and their importance is explained.
Date: March 1, 1984
Creator: Boozer, A. H.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
open access

Method of inferring the magnetic field profiles in the reversed-field pinch

Description: A diagnostic procedure is proposed that displays the toroidal and poloidal magnetic field profiles in the form of power series, through r/sup 6/. In addition to the usual external measurements, only one internal point magnetic measurement is required, if cylindrical symmetry and pressure balance are assumed. (The plasma pressure profile is also assumed to be measured nonintrusively; alternatively, it might be ignored if beta is known to be sufficiently small). The (zero-beta) method is tested h… more
Date: March 1, 1981
Creator: Gerwin, R.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
open access

Calculation of the quadrupole magnet strengths in the PEP lattice for SCORE

Description: The code, QUADS, which determines the step size in making configuration changes and calculates the field strengths of the 11 main ring quadrupole magnet families at each configuration has been completed. This code has been designed to have minimum computation time while keeping the necessary features for making future modifications of the beam lattice. It is being incorporated into SCORE, the program for the strength computation of the ring elements. The purpose of this note is to describe the … more
Date: March 1, 1978
Creator: King, A. S. & Lee, M. J.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
open access

A Fokker-Planck operator for the emission and absorption of electron plasma waves in a magnetized plasma

Description: For slab geometry the perturbation of the electrostatic wake of a superthermal test electron in a magnetized plasma ([omega][sub ce] [much gt] [omega][sub pe]) due to moderate magnetic shear is determined. Allowing for the spherical symmetry of the surfaces of constant phase to the rear of the test electron, the resonant'' field electrons causing the damping of the wave in a magnetic surface at a distance x from the test electron are those with parallel velocity [upsilon][prime][parallel] = [up… more
Date: March 1, 1993
Creator: Ware, A.A.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
Back to Top of Screen