digital Encyclopedia of Applied Physics

2003 ◽  
Keyword(s):  
Applied Physics

Electrostatic optics and aberration correction in the 1940s and today

1992 ◽  
Vol 50 (1) ◽  
pp. 6-7
Author(s):  
Gertrude F. Rempfer
Keyword(s):  
Electron Microscope ◽  
Focal Point ◽  
Focal Length ◽  
High Vacuum ◽  
Electron Optics ◽  
Applied Physics ◽  
Electrostatic Lenses ◽  
Commercial Instrument ◽  
The University ◽  
Theory And Experiment

I became involved in electron optics in early 1945, when my husband Robert and I were hired by the Farrand Optical Company. My husband had a mathematics Ph.D.; my degree was in physics. My main responsibilities were connected with the development of an electrostatic electron microscope. Fortunately, my thesis research on thermionic and field emission, in the late 1930s under the direction of Professor Joseph E. Henderson at the University of Washington, provided a foundation for dealing with electron beams, high vacuum, and high voltage.At the Farrand Company my co-workers and I used an electron-optical bench to carry out an extensive series of tests on three-electrode electrostatic lenses, as a function of geometrical and voltage parameters. Our studies enabled us to select optimum designs for the lenses in the electron microscope. We early on discovered that, in general, electron lenses are not “thin” lenses, and that aberrations of focal point and aberrations of focal length are not the same. I found electron optics to be an intriguing blend of theory and experiment. A laboratory version of the electron microscope was built and tested, and a report was given at the December 1947 EMSA meeting. The micrograph in fig. 1 is one of several which were presented at the meeting. This micrograph also appeared on the cover of the January 1949 issue of Journal of Applied Physics. These were exciting times in electron microscopy; it seemed that almost everything that happened was new. Our opportunities to publish were limited to patents because Mr. Farrand envisaged a commercial instrument. Regrettably, a commercial version of our laboratory microscope was not produced.

STUDIES OF PHOTONUCLEAR REACTIONS AND PHOTON ACTIVATION ANALYSIS IN THE GIANT DIPOLE RESONANCE REGION USING MICROTRONS

2007 ◽  
Vol 14 (1) ◽  
pp. 42 ◽  
Author(s):  
TRAN DUC THIEP ◽  
NGUYEN VAN DO ◽  
NGUYEN KHAC THI ◽  
TRUONG THI AN ◽  
NGUYEN NGOC SON
Keyword(s):  
Activation Analysis ◽  
Giant Dipole Resonance ◽  
Resonance Region ◽  
Photon Activation Analysis ◽  
Photon Flux ◽  
Photon Activation ◽  
Applied Physics ◽  
Dipole Resonance ◽  
Giant Dipole Resonance Region ◽  
Fission Neutrons

Mictrorons are accelerators of electrons and are simultaneous sources of bremsstrahlung photon flux and fission neutrons. In 1982, a microtron of seventeen trajectories Microtron MT - 17 was put into operation at the National Institute of Physics of Vietnam. Though very modest, microtons are very useful for developing countries such as Vietnam in both fundamental and applied physics research. During the recent years by using the above mentioned MT - 17 and microtrons from other institutes we have carried out different investigations. In this report we present some results obtained in the studies of photonuclear reactions and photon activation analysis in the giant dipole resonance region.

Microstructures in Elastic Media

1994 ◽  
Author(s):  
Nhan Phan-Thien ◽  
Sangtae Kim
Keyword(s):  
Computational Methods ◽  
High Performance ◽  
Chemical Engineering ◽  
Elliptic Partial Differential Equations ◽  
Parallel Computers ◽  
Computational Algorithms ◽  
Applied Physics ◽  
Advanced Students ◽  
Particulate Solids ◽  
Modeling Software

This monograph describes various methods for solving deformation problems of particulate solids, taking the reader from analytical to computational methods. The book is the first to present the topic of linear elasticity in mathematical terms that will be familiar to anyone with a grounding in fluid mechanics. It incorporates the latest advances in computational algorithms for elliptic partial differential equations, and provides the groundwork for simulations on high performance parallel computers. Numerous exercises complement the theoretical discussions, and a related set of self-documented programs is available to readers with Internet access. The work will be of interest to advanced students and practicing researchers in mechanical engineering, chemical engineering, applied physics, computational methods, and developers of numerical modeling software.

scholarly journals Topological electronics

2021 ◽  
Vol 4 (1) ◽  
Author(s):  
Matthew J. Gilbert
Keyword(s):  
Information Processing ◽  
Physical Properties ◽  
Materials Science ◽  
Electronic Device ◽  
Condensed Matter ◽  
Topological Phases ◽  
Applied Physics ◽  
New Paradigm ◽  
Topological Materials ◽  
Device Applications

AbstractWithin the broad and deep field of topological materials, there are an ever-increasing number of materials that harbor topological phases. While condensed matter physics continues to probe the exotic physical properties resulting from the existence of topological phases in new materials, there exists a suite of “well-known” topological materials in which the physical properties are well-characterized, such as Bi2Se3 and Bi2Te3. In this context, it is then appropriate to ask if the unique properties of well-explored topological materials may have a role to play in applications that form the basis of a new paradigm in information processing devices and architectures. To accomplish such a transition from physical novelty to application based material, the potential of topological materials must be disseminated beyond the reach of condensed matter to engender interest in diverse areas such as: electrical engineering, materials science, and applied physics. Accordingly, in this review, we assess the state of current electronic device applications and contemplate the future prospects of topological materials from an applied perspective. More specifically, we will review the application of topological materials to the general areas of electronic and magnetic device technologies with the goal of elucidating the potential utility of well-characterized topological materials in future information processing applications.

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