USA As Represented by Secretary of the Navy

Other

Robert R Whitlock

Nicolas A Papanicolaou

Arthur W Snow

Harold L Hughes

Jimmy Lee Davidson

Patrick J McMarr

Weng Poo Kang

David V Kerns

Michael I Bell

Samuel G Lambrakos

Barrett H Ripin

Charles M Dozier

Robert A August

Sherra Kerns

Allan Hauer

Justin S Wark

A neutron detection device includes a neutron conversion layer in close proximity to an active semiconductor layer. The device is preferably based on the modification of existing conventional semiconductor memory devices. The device employs a conventional SRAM memory device that includes an SOI substrate. The SOI substrate includes an active semiconductor device layer, a base substrate and an insulating layer between the active semiconductor device layer and the base substrate. The base substrate layer is removed from the memory device by lapping, grinding and/or etching to expose the insulating layer. A neutron conversion layer is then formed on the insulating layer. The close proximity of the neutron conversion layer to the active semiconductor device layer yields substantial improvements in device sensitivity.

Neutron detection device and method of manufacture

A resist composition with enhanced X-ray and electron sensitivity includes a plurality of chemically inert nanoparticles dispersed throughout a base resist material. The nanoparticles have a higher atomic number than the base resist material and each of the nanoparticles is formed by a nanoparticle core, e.g., of a noble metal, coated with an organic capping layer or shell. The latter renders the core dispersible and chemically compatible with the resist material surrounding the nanoparticle. A method of making a resist composition with enhanced X-ray and electron sensitivity is to provide a resist material and disperse chemically inert nanoparticles throughout the resist. The nanoparticles have a higher atomic number than the resist and a have core/shell structure. A resist composition with enhanced X-ray and electron sensitivity can be made by having a nanoparticle core, with a higher atomic number than the resist, that is coated with an organic capping layer. The nanoparticle with the core/shell structure is then dispersed throughout the resist material.

Resist composition with enhanced X-ray and electron sensitivity

The transmission cathode for X-ray generation is a device wherein an electrical current generated by a low voltage power supply produces an electron flow from the transmission cathode that is accelerated by a high voltage power supply towards an anode where X rays are emitted on impact. As the X rays are emitted, a primary beam passes through the cathode striking a sample placed outside the tube. The transmission cathode is X comprised of an electron emitter structure, preferably, an electron field emitter diode or thermionic emitter or a photoemitter or a nanotube or a pyroemitter or a piezoemitter, fabricated, preferably of elements of atomic numbers of 14 (silicon) or below, with electrically conductive components or conductive mechanical structural components, preferably, conductive silicon or diamond or aluminum or beryllium metal, and non-conductive electrical insulators or non-conductive mechanical structural components, preferably, diamond or silicon dioxide or boron carbide. The transmission cathode is transmissive to those X rays that freely flow through the transmission cathode.

Transmission cathode for X-ray production

In the submicrosecond, synchronizable x-ray source a high intensity pulsed laser is focused onto a negatively biased laser target, at high irradiance in a vacuum, producing high temperature plasma from which electrons are emitted. The emitted electrons are accelerated in a electric field formed by impressing a potential difference across a laser target-electron target gap. The positively biased electron target collects the emitted electrons, which upon impact with the electron target cause x-rays to be emitted synchronously with the incident laser pulse.

Submicrosecond, synchronizable x-ray source

A method and apparatus is disclosed for measuring the lattice parameters of single crystal material while that material is undergoing a transient shock wave. In a first embodiment, a first target is located at a preselected position in space with respect to a single crystal to be measured. A first laser beam pulse is transmitted through a beam block to the crystal to produce a transient shock wave in part of the crystal. A second laser beam pulse, synchronized to the first laser beam pulse, is transmitted to the first target to cause the first target to produce first and second sets of x-rays which are Bragg-diffracted from shocked and unshocked atomic planes of the crystal as the crystal is undergoing the shock wave. A first x-ray detector records the positions of the first and second sets of Bragg-diffracted x-rays to provide a first measurement of the lattice parameters of the crystal. In a second embodiment, a third laser beam pulse, synchronized to the second laser beam pulse, is transmitted to a second target to cause the second target to produce third and fourth sets of x-rays which are Bragg-diffracted from shocked and unshocked atomic planes of the crystal as the crystal is undergoing the shocke wave. A second x-ray detector records the positions of the third and fourth sets of Bragg-diffracted x-rays to provide a second measurement of the lattice parameters of the crystal.

Method and apparatus for transient unit cell measurement

A line imager comprising: a semiconductor body; a planar, transparent piezoelectric body having a main surface overlying and in proximity to the semiconductor body; wave propagation means for propagating acoustic waves on the main surface of the piezoelectric body to create traveling potential wells in the underlying semiconductor body; a traveling potential well path located in the semiconductor, the traveling potential well path beginning at the wave propogation means and extending straight away therefrom; semiconductor depletion means for depleting the semiconductor of majority charge carriers along the traveling potential well path, the depletion means located atop the piezoelectric body; a gate located on the semiconductor body and alongside and parallel to the traveling potential well path and adjoining the semiconductor depletion means; a plurality of sensor pixels for accumulating charge, the sensor pixels located in the semiconductor body, the pixels aligned next to each other and running parallel to, alongside and overlapping the gate so the integrated charge in each sensor pixel will proceed into their respective traveling potential wells when the potential across the gate is lowered, the gate having length at least equal to the length of the plurality of sensor pixels; and a dump gate located on the semiconductor and parallel to and overlapping the plurality of sensor pixels, the plurality of sensor pixels being situated between the dump gate and the gate, the dump gate causing the charge integrated in the plurality of sensor pixels to flow to ground when the potential across the dump gate is lowered, the dump gate being at least as long as the length of the plurality of sensor pixels.

Saw-CTD parallel to serial imager

A device for the high speed recording of photon images and nonrepetitive electrical waveforms which comprises a waveform recorder wherein surface acoustic waves excited in a can be GaAs, not layered piezoelectric-insulator-semiconductor layered structure produce a traveling electric field in the semiconductor substrate. Charges stored in the traveling potential wells and representing the instantaenous amplitude of a waveform to be recorded are transferred at static wells when a gate is dropped. Because each successive traveling well represents a different time instant of the waveform, the different spatial locations of the static wells correspond to different times. The output signal from the static wells can be selectively delayed before application to a display oscilloscope to enable display of the waveform at a rate many times slower than the actual frequency of the signal waveform.

Saw-CTD serial to parallel imager and waveform recorder

An apparatus for measuring the emissivity and opacity coefficients of a test plasma. The apparatus includes a target comprising a support structure of a carrier material with an asymmetrical sample of a test material disposed thereon, a driver for ionizing the test material into a test plasma and the carrier material into a carrier plasma, and spectrographs for measuring the intensity of photons traversing said test plasma. Embodiments including a separate photon source are also disclosed.

Radiative opacity and emissivity measuring device

A process for patterning a target for lasing at X-ray wavelengths from materials which cannot be readily shaped. A substrate of one material is placed in a gaseous atmosphere of another material, and the substrate is cooled below the freezing point of the other material so that a frozen layer of the other material condenses onto the substrate. Part of the frozen layer of the other material is masked, and the unmasked part of the frozen layer is vaporized so that the substrate of the one material is coated with the other material according to the pattern of the mask. The target made by the process is also disclosed.

Process for fabricating cryogenic targets and targets made thereby

A waveform recorder wherein surface acoustic waves excited in a piezoelecc-insulator-semiconductor layered structure produce a traveling electric field in the semiconductor substrate. Charges stored in the traveling potential wells and representing the instantaneous amplitude of a waveform to be recorded are transferred at high speed and density to different respective spatial locations. Because each successive well represents a different time instant of the waveform, the different spatial locations correspond to different times. The output signal from each of the locations can be selectively delayed before application to a display oscilloscope to enable display of the waveform at a rate many times slower than the actual frequency of the signal waveform.

System for recording waveforms using spatial dispersion

Apparatus for composing and indicating finger pattern information for a musical stringed fingerboard instrument comprising a plurality of alignably repositionable first series of first indicia, each first series representing at least one course of said stringed fingerboard instrument, the locations of said first indicia forming a mapping image of allowable locations for fingering the respective courses of the stringed fingerboard instrument to sound musical tones.

Pattern composer for fingerboard instrument instruction

Method and apparatus for indicating finger pattern information for a musical stringed fingerboard instrument comprising at least one type of first indicia in a fingering pattern specified by pairs of coordinates representing allowable locations for fingering the stringed fingerboard instrument to sound musical tones of a chord or scale, and a repositionable string stop series for selecting a correlation of the ordinal number of at least one string stop of the stringed fingerboard instrument with the indicia of the fingering pattern.

Growing community of inventors

Bethesda, MD, United States of America

Robert R Whitlock