USA As Represented by Secretary of the Navy

John H Barkyoumb

Lawrence T Kabacoff

Veerendra Kumar Mathur

Ross S Fontenot

Noel A Guardala

David J Land

According to exemplary practice of the present invention, a probe laser beam characterized by a Stokes luminescence wavelength is trained upon a thermally insulated medium; the Stokes luminescence is measured upon conclusion of the probe laser impingement of the medium. Following this first Stokes luminescence measurement, a pump laser beam characterized by an anti-Stokes luminescence wavelength is trained upon the medium; the Stokes luminescence is measured upon conclusion of the pump laser impingement of the medium. Each laser has a blocking device associated therewith. A computer is implemented to transmit control signals to open and close the two blocking devices in alternating fashion so that only one laser beam at a time is aimed at the medium. The computer is also implemented to process the measurement signals to determine heating versus cooling. If the luminescence intensity following the pump laser impingement exceeds the luminescence intensity following the probe laser impingement, then the medium is being cooled.

Automated noncontact method to discriminate whether cooling or heating is occurring

According to exemplary practice of the present invention, a probe laser beam is aligned with a position detector and is spatially/geometrically related to a pump laser beam. A temperature gradient is produced in a medium by the pump beam. Since an increase or decrease in the temperature of the medium is related to an increase or decrease in the refractive index of the medium, position sensing of the deflection of the probe beam relative to the pump beam indicates whether the medium is heating or cooling.

Photothermal deflection spectroscopy method for heating-cooling discrimination

Typical practice of the present invention performs measurement and processing of two forms of light emissions&#x2014;viz., unfiltered and filtered&#x2014;of a core-valence luminescent (CVL) scintillator impinged by ionizing radiation emanating from a radioactive source. When unfiltered, the CVL scintillator light emission is inclusive of gamma emissions and neutron emissions. When filtered by a filtering apparatus that transmits CVL light only, the CVL scintillator light emission is inclusive of gamma emissions but is exclusive of neutron emissions. Algorithmic comparison between the two sets of empirical data provides discriminative information regarding gamma emissions versus neutron emissions. Essentially, the difference is taken between the unfiltered pulse height spectra data and the filtered pulse height data. The set of pulse height spectral data thus computed via subtraction is indicative of the portion of the CVL scintillator light emissions that is inclusive of neutron emissions but is exclusive of gamma emissions.

Spectrally resolved pulse height analysis for neutron-gamma discrimination

A metal or graphite fiber is suspended in a working fluid having a high refractive index change with the temperature and a modulated laser beam heats the fiber producing a synchronous thermal wave in the fiber whose amplitude and phase are measured by passing a probe laser beam through the liquid close to the fiber and converting the probe beam deflections into an electric signal. A theoretical model of the thermal wave is used to calculate the amplitude and phase shift of a theoretical thermal wave for points along the fiber from physical characteristics of the lasers and the fiber including an estimate of the thermal conductivity of the fiber. The straight line slope of the log amplitude or of the phase shift of the theoretical wave versus distance is compare against the straight line slope of the log amplitude or the phase shift versus distance for the electrical signal and the estimated value for the thermal conductivity of the fiber is adjusted until the theoretical slope and the electrical signal slope are the same which means that the thermal conductivity of the fiber has been found.

Method of measuring the thermal conductivity of microscopic graphite

Method of doping single crystal diamond for electronic devices

A process for bonding two diamond surfaces together by

Method of joining diamond structures

A process for producing a diamond composite comprising diamond powder parles bonded together by polycrystalline diamond by (1) pressing an intimate mixture of fine opaque nondiamond carbon powder and transparent diamond powder to form a green body that is confined in either a thin walled transparent quartz vessel or a polycrystalline diamond coating; (2) using a pulse laser to quickly melt the opaque nondiamond carbon powder, and (3) allowing the carbon melt to cool and grow homoepitaxially from the surfaces of the diamond particles producing a polycrystalline diamond that bonds the diamond particles together.

Growing community of inventors

Kensington, MD, United States of America

John H Barkyoumb