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Full-Text Articles in Physical Sciences and Mathematics
Cathodoluminescence Spectroscopy Of Zinc Germanium Phosphide Zngep2, Michael R. Gregg
Cathodoluminescence Spectroscopy Of Zinc Germanium Phosphide Zngep2, Michael R. Gregg
Theses and Dissertations
Zinc Germanium Phosphide (ZnGeP2) is a nonlinear semiconductor suitable for use as a laser tuning element over the two to six micron wavelength range. Although this crystal has been studied in the past, its luminescent properties are not yet well understood. In this present study, ZnGeP2 has been examined using cathodoluminescence spectroscopy (CL). Specifically, the spectral dependence of the CL was obtained as a function of electron beam energy, beam current and temperature. The resulting CL was found to be polarized with a peak structure that was dependent on the polarization. This peak structure observed by CL …
Collisional Detachment Of Anions Using Fourier Transform Mass Spectrometry, Kevin B. Riehl
Collisional Detachment Of Anions Using Fourier Transform Mass Spectrometry, Kevin B. Riehl
Theses and Dissertations
Fourier Transform Mass Spectrometry (FTMS) is used to make energy resolved ion-neutral reaction measurements at high translational energies (up to several hundred eV). The technique is demonstrated for collisional detachment of anions, and should be easily applied to other inelastic reactions. Collisional detachment cross sections of iodine anions onto gas phase targets of neon, xenon, and trifluoromethyl iodide are measured for 1-300 eV (lab frame). Peak detachment cross sections are roughly 2, 8.5, and 7 Å2, respectively. Ion kinetic measurements show the iodine anion is unreactive in trifluoromethyl iodide at thermal energies. Positive ion chemistry is consistent with …
Design And Construction Of A Channel Electron Multiplier Based Mossbauer Spectroscopy System, Daniel J. Robbins
Design And Construction Of A Channel Electron Multiplier Based Mossbauer Spectroscopy System, Daniel J. Robbins
Theses and Dissertations
A channel electron multiplier (cem) detector system was designed and built to provide a signal to a Mossbauer spectroscopy system in an effort to obtain a better signal-to-noise ratio than achievable with a proportional counter system. Three cems are contained in a vacuum chamber built using standard components. Gamma, rays of 14.4-keV energy from a 57Co source enter from outside the chamber through a window and are absorbed by an 57Fe target near the cems. The target emits internal conversion electrons which are collected by the cems and a Mossbauer spectrometer collects the signal. The system produces a …