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Open Access. Powered by Scholars. Published by Universities.®

1994

Western Michigan University

Articles 1 - 5 of 5

Full-Text Articles in Physics

An Experimental Apparatus For Studying Double Differential Scattering By Low-Energy Multiply Charged Ions From Atomic Targets, Meenatchi S. Gopinathan Dec 1994

An Experimental Apparatus For Studying Double Differential Scattering By Low-Energy Multiply Charged Ions From Atomic Targets, Meenatchi S. Gopinathan

Master's Theses

A new differential energy-gain spectrometer with a movable parallel-plate electrostatic energy analyzer has been constructed and tested for the study of double differential (in energy and angle) cross sections for state-selective electron capture processes in collisions of low-energy multiply charged ions with atomic gases. The ion beam is produced by extracting recoil ions from a primary interaction region where these ions are generated in collisions between a neutral target gas and a fast fluorine beam from the WMU tandem Van de Graaff accelerator. An einzel lens is used to focus the ion beam extracted from the recoil-ion source into a ...


Absolute Photonic Band Gaps Of Zincblende, Ulrich Bass Dec 1994

Absolute Photonic Band Gaps Of Zincblende, Ulrich Bass

Master's Theses

One concept of examining the propagation of an electromagnetic wave through a periodic structure is the dispersion curve which relates the frequency of the propagating wave to its wave vector. In some cases frequency ranges occur where no propagation is possible. These ranges are called absolute photonic band gaps as far as periodic dielectric structures are concerned.

In my thesis I am interested in the dispersion curve of a Zincblende type dielectric array. Zincblende is a diamond-like structure and it has been shown that diamond structures possess absolute photonic band gaps. In studying Zincblende we want to gain deeper insight ...


Determination Of The Bulk Modulus Of A Lennard-Jones Solid, Spencer A. Van Roekel Jr. Dec 1994

Determination Of The Bulk Modulus Of A Lennard-Jones Solid, Spencer A. Van Roekel Jr.

Master's Theses

The quantum Monte Carlo method is used to determine the bulk modulus of a Lennard-Jones solid. The quantum Monte Carlo method is discussed in detail and is compared with other numerical methods used previously.

The zero pressure bulk modulus of a Lennard-Jones solid is computed at a number of different temperatures and compared with experimental data.


The Photonic Band Structure Of Dielectric Systems With A Frequency Dependent Dielectric Function, Jiezhou Liu Dec 1994

The Photonic Band Structure Of Dielectric Systems With A Frequency Dependent Dielectric Function, Jiezhou Liu

Master's Theses

The concepts of band theory for electrons can be employed to describe the behavior of electromagnetic waves propagaiting in periodic dielectric structures with a frequency independent dielectric function. These periodic structures can produce photonic band gaps in which the propagation of electromagnetic waves is strictly prohibited. The introduction of a frequency dependent dielectric function in such systems gives rise to strong changes of the photonic bands in the neighborhood of the frequency resonance of the dielectric function.

In my thesis, the photonic band structure of a dielectric system with a frequency dependent dielectric function which undergoes a dielectric resonance will ...


A Procedure For G-Matrix Calculation From A Momentum Space Potential, Zhaohui Gao Busche Aug 1994

A Procedure For G-Matrix Calculation From A Momentum Space Potential, Zhaohui Gao Busche

Master's Theses

In this work a numerical procedure was found to calculate the G-matrix in momentum space with a momentum space potential. The integral equation for the G-matrix was solved by conversion to a matrix equation. Two numerical integral methods, three-point Simpson method and Gaussian integral method, were employed in this process to determine the more efficient method.

The resulting G-matrix in momentum space was Fourier transformed into coordinate space. This was compared with the results of the G-matrix calculated from coordinate space directly as well as the results from solving the Bethe-Goldstone equation. A 2% accuracy was achieved with both the ...