Abstract: The composition, free carrier concentrations, and other properties of thin films and graded layers embedded in film stack structures are measured by the method of the invention, which is based upon the application of two novel algorithms to extract the composition of a measured layer independently of the confounding effects of additional layers, and which can be effected even when calibration samples are not available with the same layered structure as the samples to be measured. The method uses sample model-based analysis algorithms to extract the dielectric function of the layer to be measured, combined with model-based analysis to relate the composition of the layer to its dielectric function.

Abstract: A device for detecting neutrons includes a semi-insulated bulk semiconductor substrate having opposed polished surfaces. A blocking Schottky contact comprised of a series of metals such as Ti, Pt, Au, Ge, Pd, and Ni is formed on a first polished surface of the semiconductor substrate, while a low resistivity (“ohmic”) contact comprised of metals such as Au, Ge, and Ni is formed on a second, opposed polished surface of the substrate. In one embodiment, n-type low resistivity pinout contacts comprised of an Au/Ge based eutectic alloy or multi-layered Pd/Ge/Ti/Au are also formed on the opposed polished surfaces and in contact with the Schottky and ohmic contacts. Disposed on the Schottky contact is a neutron reactive film, or coating, for detecting neutrons. The coating is comprised of a hydrogen rich polymer, such as a polyolefin or paraffin; lithium or lithium fluoride; or a heavy metal fissionable material.

Abstract: Simultaneous measurement of neutron flux and temperature is provided by a single sensor which includes a phosphor mixture having two principal constituents. The first constituent is a neutron sensitive Li6F and the second is a rare-earth activated Y2O3 thermophosphor. The mixture is coated on the end of a fiber optic, while the opposite end of the fiber optic is coupled to a light detector. The detected light scintillations are quantified for neutron flux determination, and the decay is measured for temperature determination.

Abstract: A method is provided for the quantitative determination of fissile material content in small size particles present in samples. The samples are sandwiched in organic sheets and then submitted to a defined thermal neutron fluence whereupon fission products of the fissile material in the sample create in the sheets fission tracks which are rendered visible by etching the sheets. Then the size of selected particles having created such tracks is. determined by means of a microscope and thereafter these visible tracks of the selected particles are compared to pre-established standard tracks obtained by the same process from particles of different stepped known size and enrichment ratio.

Abstract: The present invention relates to an ultraviolet radiation detector in general and more specifically to a solar blind ultraviolet radiation detector; that is, a detector insensitive to the radiation of sunlight reaching the earth's surface but sensitive to UVC wavelengths in the spectrum, defined as the interval 200 nm-280 nm. The solar blind detector is base on the use of photochromic compounds in conjunction with ultraviolet wavelength-selective chemical blocks and their incorporation into optically clear polymer matrices. The photochromic compound is selected from the group comprising spiropyran molecules spirooxazine molecules and chromene derivatives. Applications for such device are as numerous as the sources of UVC radiation. An obvious use for such Solar Blind UVC detector is monitoring the output of UVC sources used in the decontamination of water and air (water treatment and air purification) and for sterilization of medical instruments.

Abstract: A low energy radiation detector for wireline applications and the like is provided with a housing made of carbon fiber and eopxy binder composite which is relatively transparent to x-radiation, while also being optically opaque and providing an hermetic enclosure for a scintillation crystal disposed inside the housing. Also disclosed is a neutron detector having such a housing.

Abstract: A color radiography system comprises a color light emission sheet having a phosphor layer that contains a phosphor emitting in a plurality of colors to radiation and emits light under irradiation of radiation transmitted through a subject to be inspected, and a color film or a color camera that detects the light emissions of the plurality of colors into the respective colors. In the phosphor layer, a phosphor is used that has a primary emission component corresponding to one emission color in a visible light region and at least one secondary emission component, the secondary emission component having an emission color different from that of the primary emission component and a ratio of light emission to radiation of the same intensity being different from that of the primary emission component. According to the present color radiography system, image information of a plurality of colors having different sensitivity characteristics can be obtained.

Abstract: A radiation detection method and apparatus for detection of radiation in a small, portable, relatively inexpensive device. A radiation sensitive memory device and a radiation hardened memory device receive digital data from a digital data generator such as a pseudo-random word generator. The radiation sensitive memory device outputs an exposed digital data stream which, while stored in the radiation sensitive memory device, is susceptible to radiation incident upon the radiation sensitive memory device. The radiation hardened memory device is much less sensitive to radiation than the radiation sensitive memory device such that the test digital data stream output by the radiation hardened memory device is much less effected by radiation than the exposed digital data stream. The exposed digital data stream and the test digital data stream are compared to determine whether the exposed digital data stream was exposed to radiation while stored in the radiation sensitive memory device.

Abstract: The present invention relates to a Rn222 (radon) and Rn220 (thoron) radiation monitor that uses alpha-track detection film in multiple, separate chambers to detect radiation. The invention further describes use of different diffusion barriers in each of the chambers to allow for signal differentiation between the chambers. The signal differentiation allows for differentiation between the levels of thoron and radon in the atmosphere tested. In a preferred embodiment of the invention, the radiation monitor has three or four separate chambers, each with an electrically conductive housing and a cap with at least one opening to permit entry of ambient air. Inside each of the housings is an alpha-track detecting film, such as a solid-state nuclear track detector (SSNTD), with a thin electrically conducting cover. In one or more of the chambers is a diffusion barrier and seal placed within the housing to generally isolate the detecting film from thoron radiation in the housing.

Abstract: An apparatus and method of detection and visualization of an infrared laser beam using an optically transparent or opaque solid medium doped with at least one active chromophore dye molecule to provide conversion of infrared radiation to visible light by means of two or three-photon absorption followed by emission of a visible photon is provided. A method of verifying mode-lock in mode-locked infrared laser sources and measuring the temporal and spatial shape of ultra short laser pulses having pulse durations between a few femtoseconds and hundreds of picoseconds is also provided.

Abstract: A radiation image information reading apparatus has a main assembly which incorporates an exposure unit, an image information reading unit, an erasing unit, and a circulatory feed system. The image information reading unit has an auxiliary scanning feed mechanism for feeding a stimulable phosphor sheet vertically in an auxiliary scanning direction, and a laser beam applying mechanism for applying a laser beam substantially horizontally to the stimulable phosphor sheet which is being fed in the auxiliary scanning direction and scanning the stimulable phosphor sheet with the laser beam in a main scanning direction. The radiation image information reading apparatus is relatively simple in structure and small in size.

Abstract: A black-out curtain system (S) reduces undesired viewing by an external observer (O) through an opening (10) in a barrier (12) into an interior space (14). A filter sheet (16) that transmits Electro-Magnetic (EM) radiation (18) is adapted to intercept EM radiation originating in the interior space (14) from exiting the interior space (14) through the opening (10). The filter sheet (16) suppresses EM radiation below a selected cut-off frequency (C), and passes EM radiation above the selected cut-off frequency. An internal night viewer (20) detects only EM radiation having a frequency above the selected cut-off frequency (C). An interior illumination source (22) supplies the interior space (14) EM radiation having a frequency below the selected cut-off frequency (C).

Abstract: A dosimeter device that is fabricated from a flat member separated into panels along fold lines. In an illustrated embodiment, a first panel has two attenuators thereon, a first attenuator formed of a first material and a second attenuator formed of a second material. The first panel also has a window or opening formed thereon. A second panel also has two attenuators thereon, a third attenuator formed of the same material as the first attenuator on the first panel and a fourth attenuator formed of the same material as the second attenuator on the first panel. The second panel is separated from the first panel by a fold line, and the second panel also has a window or opening formed thereon. A third panel is separated from the second panel by a second fold line, and has a radiation sensitive member thereon.