Compound semiconductors such as gaas and inp based iii-v alloys and ii-vi alloys such as cdte and hgcdte will have widespread use in defense-related electronics systems. a variety of techniques exist for the microanalysis of chemical constituents contained in these materials. the proposed research… More

This proposal is to determine the feasibility of laser microprobe mass analysis (lmma) for the quantitative characterization of biological materials. specifically, the microanalytical capability of lmma will be evaluated through localized "in situ" elemental and molecular analysisof biological… More

Although industrial applications are still limited, surface modification of metals by ion implantation has been shown toimprove wear resistance and fatigue life and reduce frictionfeatures which can lead to improved manufacturing productivity, product quality and reduced dependence on imported… More

The development of advanced compound semiconductor materials for the next generation semiconductor devices will increase the demands for sophisticated materials characterization. although a variety of surface and microanalytical techniques exist for chemical characterization of these materials, no… More

The research proposed in this phase i effort will evaluate the feasibility of developing a quantitative laser ionization mass spectrometry (lims) technique for the microanalytical characterization of insulating materials. the development of this quantitative capability could have both significant… More

The proposed research will evaluate the organic microanalysis capability of laser ionzation mass spectrometry (lims). this technique, which is also referredto as laser microprobe mass spectrometry, has been shown to provide useful organic microanalysis for selected organicsolids; however, a… More

The aging of polymers leads slowly but inextricably to changes in their chemical and mechanical properties. brittleness can arise by several aging mechanisms and often results in eventual formation of cracks and other imperfections. all organic materials undergo slow oxidation called autoxidation,… More

During the past five years, extensive developmental effort has led to the production of computer-compatible position-sensitive ion detection systems for stigmatic imaging, secondary-ion mass spectrometry. a tremendous bodyof knowledge and several products have resulted from this work, with… More

Commercially available glow-discharge mass spectrometry (gdms) and high-performance secondary ion mass spectrometry (sims) instrumentation will be evaluated for quantitative trace element analysis of very small biological samples. submilligram or microliter quantities of bovine serum, bovine liver,… More

In phase i, the initial characterization of electronic structure at algaas/gaas interfaces by electron beam electro-reflectance (eber) is proposed, specifically for the investigation of quantum well and hemt structures. these interfaces have been studied by related techniques, and have been shown to… More

In phase i, we propose to investigate the use of electron beam electro-reflectance (eber) to automatically map the band gap of high x algaas (x>0.38) epitaxial films on full, 3 inch gaas substrates at room temperature. these compositions of algaas are important for high-efficiency grinsch lasers and… More

Traditional methods, such as chemical etching and tem, for characterizing defects in semiconductors are not entirely adequate at the vlsi/ulsi level of integration. sims coupled with defect decoration by a sims-sensitive element is proposed as a complementary method. the objectives of this phase i… More

We propose to analyze interplanetary dust particles (idp) using several microanalytical techniques. the analysis will require the development of non-contaminating techniquesfor particle preparation and analysis especially with respect to the distribution of the biogenic elements h, c, n, o, p and s.… More

This phase i research program will evaluate the feasibility of obtaining microanalytical characterization of organic species contained in biological tissue specimens. this evaluation will be performed using state-of-the-art secondary ion mass spectrometry (sims), an ion microscope, and microprobe… More

Position-sensitive detectors (psds) are widely used for charged particle and photon spectroscopy as well as in imaging applications. the detectors presently available have adequate lateral resolution, but constrain researchers to relatively low particle count rates compared to single channel pulse… More

We propose to construct and test an imaging neutron activation analysis detector capable of discerning element concentrations on a point-by-point basis. neutron activation analysis is an extremely powerful method for measuring major, minor, and trace element concentrations in a wide variety of… More

Flyash is one of the most common forms of environmental pollution. because of small particle size, direct measurements of individual particles have been restricted to morphology and elemental composition. organic analysis has been accomplished mostly by solvent extraction, thereby forcing reliance… More

Charles evans & associates will construct and test an imaging neutron activation analysis detector capable of discerning element concentrations on a point-by point basis.neutron activation analysis is an extremely powerful method for measuring major, minor, and trace element concentrationsin a wide… More

We propose to develop secondary ion mass spectrometry (sims)based imaging isotope ratio techniques for isotopic microanalysis of mineral deposits. we will combine this capability with sims based trace element microanalysis. thepetrogenesis of ore deposits often involves an aqueous solution by which… More

This research addresses the need for improved analytical capabilities in the analysis of the near surface composition and depth distribution of low z elements (i.e., those having low charge numbers, such as c, n, and o) in materials systems such as polymers and plastics. the research objective is to… More

The objective of this phase i research is to determine the feasibility of the matrix-assisted laser desorption (mald) technique on our triple electrostatic sector time-of-flight mass spectrometer (tof-ms) for the analysis of bio-organic compounds. this particular tof-ms was developed at charles… More

The phase i research will evaluate the feasibility of using time-of-flight secondary ion mass spectrometry (tof-sims) to provide sensitive and structurally significant characterizatin of the surface composition of biological membranes. the research will analyze a variety of model membrane systems in… More

A phase ii nih sbir grant for ion imaging analysis of biological matrices previously awarded to charles evans and associates, is producing very promising results. this research uses tof-sims which stigmatically focuses secondary ions produced by bombardment with a cs(+) primary beam. this… More

The goal of this project is development of a time-to-digital converter (tdc) optimized for time-of-flight energy and mass spectrometers. the tdc will combine 100 ps time resolution, 30 ns dead time, 2048 stops over a total time interval longer than 100 ms, and an average data rate limited by bus… More

For imaging or position-sensitive detection (particle counting) of low-intensity electron, ion, or photon beams, a common approach is to use a microchannel plate (mcp) intensifier followed by a position-sensitive anode. the resistive anode encoder (rae) is an anode design that is proven to be… More

This Phase I research will evaluate the capabilities of secondary ion mass spectrometry (SIMS) in performing stable isotope ratio analysis and isotope ratio imaging of hard and soft biological tissues. The research program will specifically evaluate SIMS isotope ratio accuracies and image… More

We will test the feasibility of combining the activation mechanism of photodissociation (PD) andthe MS/MS technique of time-resolved ion kinetic energy spectrometry (TRIKES) to perform MS/MS onthe TOF-SIMS. The successful implementation of PD and TRIKES on the TOF-SIMS will not onlyincrease the… More