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Search Publications by: Don Porter (Fed)

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Displaying 1 - 12 of 12

Characterizing and Back-Porting Performance Improvement

September 25, 2013
Author(s)
Clif Flynt, Phil Brooks, Donald G. Porter
The Tcl interpreter is constantly being modified and improved. Improvements include new features and performance boosts. Everyone wants to use the latest releases with the newest improvements, but corporate users with large code bases may not be able to do

Velocity of Transverse Domain Wall Motion Along Thin, Narrow Strips

June 1, 2004
Author(s)
Donald G. Porter, Michael J. Donahue
Micromagnetic simulation of domain wall motion in thin, narrow strips leads to a simplified analytical model. The model accurately predicts the same domain wall velocity as full micromagnetic calculations, including dependence on strip width, thickness

Analysis of Switching in Uniformly Magnetized Bodies

September 1, 2002
Author(s)
Michael J. Donahue, Donald G. Porter
A full analysis of magnetization reversal of a uniformly magnetized particle by coherent rotation is presented.The magnetization energy of the particle in the presence of an applied field H is modeled as E = ( 0/2)MT DM - 0HTM.This model includes shape

Generalization of a Two-Dimensional Micromagnetic Model to Nonuniform Thickness

June 1, 2001
Author(s)
Donald G. Porter, Michael J. Donahue
A two-dimensional micromagnetic model is extended to support simulation of films with non-uniform thickness. Zeeman and crystalline anisotropy energies are scaled by the local thickness, and exchange interaction between neighbor elements is scaled by the

Switching Dynamics and Critical Behavior of Standard Problem No. 4

June 1, 2001
Author(s)
Robert McMichael, Michael J. Donahue, Donald G. Porter, J Eicke
We report switching dynamics for uMAG standard problem no. 4, a 500 nm x 125 nm x 3 nm rectangle of material with properties to mimic Permalloy. Siwtching dynamics are calculated for fields applied instantaneously to an initial s-state: Field 1 at 170o and

Behavior of MAG Standard Problem No. 2 in the Small Particle Limit

May 1, 2000
Author(s)
Michael J. Donahue, Donald G. Porter, Robert D. McMichael, J Eicke
For a uniformly magnetized rectangular particle with dimensions in the ratio 5 : 1 : 0.1, the coercive and switching fields in the (1,1,1) direction are determined to be H c / M s = 0.057069478 and H s / M s = 0.057142805. Previous micromagnetic

Domain Wall Traps for Low-Field Switching of Submicron Elements

May 1, 2000
Author(s)
Robert D. McMichael, J G. Eicke, Michael J. Donahue, Donald G. Porter
In magnetic random access memory, power consumption depends on the coercivity of the magnetic elements in the memory cells. In this article a new method is described that uses a domain wall trap element shape to reduce both the coercivity and the

Measurement and Standards for Computational Science and Engineering

March 1, 1999
Author(s)
Ronald F. Boisvert, J L. Blue, Daniel W. Lozier, William F. Mitchell, Roldan Pozo, Michael J. Donahue, Donald G. Porter
This report describes current work within ITL on the development of measurement and standards technology to improve the practice of computational science and engineering.