Abstract: A blue-light polymerizing system comprises a xenon arc lamp in which its sapphire window includes a blue-bandpass filter coating. This eliminates any external color filters that would otherwise be necessary for the polymerization of dental composite materials in a patient's mouth. The blue-bandpass filter coating causes the xenon arc lamp to heat an extra 10° C. higher than would otherwise be the case. So a special anode heatsink is fitted in which the front and back halves of each radial fin have been separated, and one of these groups of separated fins has been tilted off normal. Such changes the otherwise laminar airflow through the anode heatsink fins to a turbulent flow that is better able to collect heat and carry it off.

Abstract: A detonator with a base portion including a header wall terminating in a support surface; an initiator on the support surface; an explosive charge spaced from the initiator; and a cap having an interior top surface and an enclosure wall extending downward from the interior top surface and surrounding the initiator and the explosive charge. The wall terminates in a rim secured at a location along the header wall corresponding to the thickness of the initiator, the spacing between the initiator and the explosive charge, and the thickness of the explosive charge thereby ensuring that the explosive charge is in communication with the interior top surface of the cap.

Abstract: A three-axis radiation detection system whose inner and outer electrodes are shaped and positioned so that the shortest path between any point on the inner electrode and the outer electrode is a different length whereby the rise time of a pulse derived from a detected radiation event can uniquely define the azimuthal and radial position of that event, and the outer electrode is divided into a plurality of segments in the longitudinal axial direction for locating the axial location of a radiation detection event occurring in the diode.

Abstract: The present invention discloses a method for determining an atomic number of a location on a material using a radiation at a predetermined energy. The method comprises the steps of (i) generating the radiation at a first spectrum and a second spectrum penetrating through the location on the material; (ii) detecting a first profile corresponding to the first spectrum and a second profile corresponding to the second spectrum; and (iii) determining the atomic number of the material at the location based on the first profile and the second profile.

Abstract: A hermetically sealed laser actuator/detonator includes a housing with an orifice for receiving a laser beam and a chamber having a first lens, a compression sealing material at least partially about the first lens, and an energetic material optically coupled to the first lens.

Abstract: A seal assembly includes a first plate or member having a recess with a bottom mating surface which receives sealing ring therein and a second plate or member having a sealing surface for contacting a metallic sealing ring. First and second plates or members are coupled together by a plurality of fasteners or bolts. By tightening the fasteners the sealing ring is loaded, and thus, compressed to plastically deform and create an annular seal between the first and second members. Metallic sealing ring has a first annular sealing surface, a second annular sealing surface, an annular inner surface and an annular outer surface. The first annular sealing surface faces in a first axial direction to contact sealing surface of first member for creating a first annular sealing dam therebetween.

Abstract: A method for improving the speed of convergence to sub-least-significant-bit accuracy and precision in a digital signal averager when the measurements are averaged over many samples where the noise inherent in the signal is not large compared to 1 LSB. A slider offset circuit implements the method which adds offsets to an analog input signal acquired from an analog sensor. The slider offset circuit compensates for limitations in the resolution of an analog-to-digital converter by adding a sub-least-significant-bit offset to the input signal. Similarly, the slider offset circuit compensates for the differential non-linearity using a Gatti offset which are whole number multiples of the average voltage bin width. Speed of convergence to sub-LSB accuracy is further improved by employing non-consecutive increments in the two sliders.

Abstract: A sealing assembly is disclosed for creating a seal between first and second mating members or components. The sealing assembly basically includes a seal retainer with one or more annular seals coupled thereto. The seal retainer including a substantially flat body portion lying in a plane and with at least one resilient retaining element integrally formed with said body portion as a one-piece, unitary member for engaging the seal(s) to retain the seal(s) thereto. The seal retainer has an indicator formed on its body portion to indicate if the seal retainer has been used. In the preferred embodiment the indicator is a raised protrusion which normally extends outwardly from the plane of body portion of the seal retainer. Once the seal retainer is used, the raised protrusion of the indicator is deformed inwardly into the plane of the body portion of the seal retainer.

Abstract: An autocalibrating multichannel analyzer (MCA) for spectroscopy. The autocalibrating MCA includes a data collection unit, wherein is included a detector and a multichannel buffer (MCB). The detector produces an analog signal representing selected parameters of a radioactive sample. The MCB includes a signal conditioner for converting the analog signal into a digital signal and a processor for sorting and counting the signals received from the detector. The interface unit includes a processor for data analysis, at least one output device to display information, at least one input device to accept commands, at least one memory device for storing data, and an automatic calibration system to correct data for errors introduced by the data collection unit and the surroundings. The automatic calibration system compares parameters collected from a known calibration sample against parameters stored in the system with little intervention by the operator.

Abstract: A method and apparatus for compression and filtering of data associated with spectrometry. The method and apparatus serves to recognize peak events and filter data associated with background noise, thereby reducing the volume of data to be transferred to storage and the data transfer rate required for storing the desired data. The method of the present invention monitors the value of each data point as it is encountered and compares it to the previously encountered data to determine whether it is on or very near a peak. The y values for each data point are continuously summed and averaged to determine the average background level. The deviation .delta..sub.i is determined for each subsequent data point and is used to determine a threshold. Each subsequent data point is compared to the threshold and, if found to be above the threshold, is assumed to be part of or very near a peak. At this point, the averaging is stopped until a subsequent data point is determined to be below the threshold.

Abstract: An active quench circuit for an avalanche current device applies a bias voltage to reverse bias an avalanche current device above its avalanche breakdown voltage; a current amplifier circuit having a turn-off speed slower than the avalanche speed of the avalanche device and responsive to the avalanche current of the avalanche device generates an overshoot current continuing after the end of the avalanche current; and a feedback circuit responsive to the overshoot current generates a quenching voltage for reducing the bias voltage below the avalanche breakdown voltage to quench the avalanche current of the avalanche device.

Abstract: An apparatus particularly suited to the inspection of carp in trucks, shipping containers and the like uses a beam of high energy x-rays, e.g., in the order of 8 Mev. A first detector is aligned with the beam to detect x-rays that have passed directly through the cargo. A second detector, located adjacent the first detector, receives x-rays that are inelastically forward scattered from the cargo at an angle in the range of 4.degree. to 10.degree.. Comparison of the relative amounts of x-ray received at each of these detectors with values for known materials identifies the nature of the cargo. The beam is fan-shaped and preferably vertical, and the detectors are preferably linear arrays of detector elements. Collimators define the field of view of the two detector arrays so that they both include a common spatial location within the cargo.

Abstract: A digital gated base line restorer system for an ionizing radiation spectroscopy device includes a gated base line restorer circuit, responsive to pulses passing through the device, for generating a weighted average of previous base line sample points and applying it to the pulses to compensate for base line offset errors; and a control circuit responsive to the pulses passing through the device, to enable the gated base line restorer circuit to generate the weighted average during intervals between the pulses and applying it during the random pulses.

Abstract: A time analyzer having an improved interpolator with temperature compensation. The time analyzer of the present invention can be operated in a wide range of temperatures without need of recalibration in the field. The device includes hardware for making a coarse time measurement. A fine time measurement is obtained by interpolating within a cycle of the master clock. A temperature correction look up table is produced which incorporates information unique to each analyzer. Information stored in the look up table of each instrument is used to correct time measurement for enhanced precision.

Abstract: A brush seal device for sealing a high pressure area from a low pressure area. The brush seal device comprises a plurality of bristles arranged annularly. An annular back plate is positioned concentric to and on the low pressure side of the bristles, the back plate having a recess adapted to delay contact of the bristles with the back plate upon application of the pressure across the brush seal device. A flexible annular front plate is positioned adjacent to and concentric with the bristles on the high pressure side of the bristles. This combination of elements helps to reduce uneven wear of the bristles in a brush seal device and, therefore, helps to prolong the life of such a seal.

Abstract: A clamping device is disclosed for coupling peripheral flanges of a pair of tubular members together. The clamping device has a retaining member for coupling the peripheral flanges of the tubular member together, with first and second coupling ends being releasably coupled together by a latch assembly from an open position to a closed position. The latch assembly has a connecting member with a pivoting end and an anchoring end. The pivoting end of the connecting member is pivotally coupled to the first coupling end about a pivot axis between an unengaged position where the anchoring end is spaced from the second coupling end and an engaged position where the anchoring end is removably coupled to the second coupling end. The latch assembly further has a retention member coupled to the pivoting end of the connecting member for retaining the connecting member to the first coupling end.

Abstract: An automatic pole-zero adjustment circuit for an ionizing radiation spectroscopy system includes a digital conversion circuit, responsive to random analog pulses passing through the system for converting the random analog pulses to digital pulses; a programmable digital shaping filter including means for applying a pole-zero cancellation adjustment to compensate for under/overshoot at the output of the programmable digital shaping filter; digitally programmable sampling means including means for defining a window for sampling the trailing edge of the digital pulses and means for sampling the digital pulses during that window to determine the presence of undershoot or overshoot; and a digitally programmable control circuit, responsive to the pole-zero sampling means, for driving the programmable digital shaping filter to introduce an under/overshoot correction signal to the digital programmable shaping filter.

Abstract: A method of manufacturing a spark gap device. The method includes using standard metal transistor base and cap components, machining the base to cut out a portion of the top of the base, filling the base with an insulative substrate and placing a pin through the insulative substrate, depositing a first electrode on the top portion of the base in electrical contact with the metal portion of the base, and sealing the cap with respect to the base. Also featured is a spark gap device which eliminates heat related and electrode sputtering failures associated with prior art glass or ceramic spark gap devices.

Abstract: An automatic pulse top optimization circuit for an ionizing radiation spectroscopy system includes a conversion circuit, responsive to random analog input pulses passing through the system, for converting the random analog pulses to digital pulses; a programmable shaping filter, responsive to the digital pulses, for producing an output of predetermined shape which maximizes the precision and accuracy of the anticipated measurement; pulse shape sampling means including means for defining a window for sampling the top of the pulse and means for sampling the pulses during that window to determine the presence of a deviation from the predetermined shape; and a control circuit, responsive to the pulse shaped sampling means, for programming the programmable shaping filter to compensate for a deviation in the predetermined shape.

Abstract: A sealing ring is disclosed for radially sealing two coaxial surfaces. The sealing ring has an annular convolution with a first radially facing sealing surface and a pair of annular leg portions forming second and third radially facing sealing surfaces. Each of the leg portions are provided with an annular bend to increase the radial resiliency of the seal. In an alternate embodiment, each of the leg portions of the sealing ring has a pair of annular bends. In yet another embodiment, the sealing ring is constructed of a pair of plies or layers.