Abstract: A method for pretreatment of a photoresist layer adhered to a semiconductor wafer prior to charged particle beam processing. The method includes bombarding the photoresist layer with ions which are electrically inactive with respect to the wafer. Suitable ions include ions of the noble gases. The pretreatment method causes rapid photoresist outgassing and carbonization without altering the electrical properties of the wafer. Outgassing during subsequent processing is thereby reduced. The pretreatment method is particularly applicable to ion implantation wherein dose measurement errors resulting from photoresist outgassing are reduced. The pretreatment method is performed at high current to minimize the effect on system throughput.

Abstract: An X-ray receptor for producing electrical signals representative of an X-ray image. An array of semiconductor elements is mounted on at least one support, each element being formed of semiconductor material which is (1) an element of Group 4A of the Periodic Table of Elements or a compound of such an element, or which is (2) at least one element of Group 3A of the Periodic Table of Elements together with at least one element of Group 5A of the Periodic Table of Elements, and having at least one PN junction therein. The array is positioned to receive impinging X-rays and to produce electrical signals in response thereto. Electrical conducting leads are supported on the support, and the electrical signals which are produced by respective ones of the semiconductor elements are coupled to these electrical conducting leads.

Abstract: The invention is directed to a container for receiving and safely storing radioactive or other materials damaging to living organisms, especially such materials as vitrified radioactive fission products or irradiated nuclear reactor fuel elements. The container includes a vessel and a sealing cover. The vessel has a circular opening at one of its ends for receiving the materials to be stored therein, and a sealing cover is seated in this opening to tightly seal the container. In order to obtain a container of the kind which has the required high impermeability to gas, the open end of the inner bore of the vessel is widened to define a conical surface. A sealing cover is pressed into the vessel at this conical surfce. The sealing cover has a peripheral surface which converges toward the interior of the vessel and which has a taper corresponding to that of the conical surface of the vessel.

Abstract: A beam of light falling within the range of 180 to 3,000 nanometers is transmitted through a flow cell in an optical compartment of an absorbance detector after warm up of the equipment while the eluant flows through the flow cell from a chromatographic column. The column extends upwardly from the absorbance detector into an air chamber having a volume of approximately 0.25 cubic foot formed with acrylic walls. Air flows from the absorbance detector under the power of a fan at approximately 10 cubic feet per minute upwardly through an air duct having a cross section of approximately 1.5 square inches to the top where it connects with the air chamber, the speed of the motor being adjustable until temperature varies less than one degree Celsius between the flow cell and the lower 10 centimeters of the column. Under these conditions Schlieren noise from the flow cell due to flow-induced thermo-optical effects is reduced.

Abstract: A medical diagnostic system utilizing the principles of nuclear medicine is disclosed. The system includes a gantry having a detector support section supported by a carriage section located on a rail system for movement along a linear path. A nuclear detector is supported on a pair of weighted arms pivotally mounted on the detector support system about an axis perpendicular to the rail system. The detector is itself pivotally mounted near an end of the weighted arm pair for tilting rotation about an axis parallel to the arm pivot axis. Mechanism is provided for rotating the weighted arms additionally about an axis parallel to the rail system, in order to accomplish orbital motion of the detector. All three of these rotational movements are power actuated. A stationary pedestal and cantilevered patient support table is located between the rails of the rail system, with the patient table extending longitudinally with respect to the rails.

Abstract: In the present invention, the temperatures of cooling passages in a gas turbine engine blade are changed, as by forcing a heated gas through them. The infrared signatures of the channels are measured during the initial temperature transient of the channels and the signatures are compared with a reference. The reference may be the signature of other channels on the same blade.

Abstract: A well logging instrument for use in a cased well bore and containing a sealed source of fast neutrons and two identical thermal neutron detectors with a volume of four atmospheres of helium-3 gas. The formation surrounding the cased well bore is bombarded with high energy neutrons and the two thermal neutron detectors are spaced apart from one another and from the source to receive slowed down or thermal neutrons from the surrounding formations. The epithermal or fast neutrons striking the formation are slowed down by fluids containing great quantities of hydrogen or chlorine atoms, creating thermal or slow neutrons, which the detectors respond to logrithmically, but independently. The counting rate of the detectors are processed independently to count rate meters and to a recorder to present two outputs of information. The presence or absence of hydrogen and chlorine atoms in the formations as detected by each detector determines the amount of sweep or deflection of each recorder pen.

Abstract: The present invention provides a radiation detector arrangement wherein the detecting faces of the detecting elements are arranged at an acute angle to the plane of radiation, i.e., the plane parallel to the direction of relative movement between the radiation detector and the radiation to be detected. The remaining portions of the detector elements are shielded from receiving radiation from the source, by, for example, adjacent detecting elements or layers of high Z materials. As a consequence, the individual detector elements are sensitive to their position with respect to the radiation source, without the necessity of employing collimators. In a preferred embodiment of the invention, the individual detector elements are wedge-shaped, and are arranged in groups of four to define detectors having pyramidal recesses. In further embodiments of the invention, four detecting elements may be arranged in a back-to-back relationship, in the array, to form pyramidal detectors.

Abstract: A stimulable phosphor sheet carrying a radiation image stored therein is scanned with stimulating rays which cause the stimulable phosphor sheet to emit light in proportion to the radiation energy stored therein. The emitted light is photoelectrically detected to obtain sequential electric signals of respective picture elements of the radiation image. The interference among the electric signals of the respective picture elements which is caused by the light emission response characteristics of the stimulable phosphor to the stimulation is eliminated electrically. The correction is conducted by adding a differentiated value of the sequential electric signals of the respective picture elements to the sequential electric signal of the respective picture elements.

Abstract: For use in a well logging tool which responds to randomly spaced pulses of different amplitudes, a pulse processing circuit featuring reduced dead-time is incorporated. Typically, it can be used with either a gamma ray or neutron detector. The circuit enables mixed amplitude pulses with irregular spacing to be processed with relatively different rise and fall times. The circuit processes the trailing or following portion of a pulse differently from the leading or rising portion to enable a separate following second pulse to be observed.

Abstract: Radioactive specimens are placed in the well (12) of a plastic scintillator body (11), and the light flashes from the scintillator body (11) are picked up by a photomultiplier tube (13). The anode (44) and dynodes (43) of the photomultiplier tube (13) are electrically isolated and a selected biasing voltage is provided across the cathode (42) and dynodes to operate the photomultiplier tube in its linear range at the activity level of the specimen. At high activity levels, the current flowing from the anode (44) is measured by an electrometer (21) to determine a value which is directly related to the activity of the specimen, whereas at lower activity levels where anode current is not accurately measurable, the pulses at the last dynode (50) are counted to determine the scintillation rate and thereby the activity level of the specimen.

Abstract: The invention substantially eliminates measurement errors in radiation field strength due to circuit propagation time delays and slow drift conditions, Geiger-Mueller tube turn-on time and response curve variations, and the need to manually calibrate the measurement apparatus in high radiation fields to compensate for time errors. The exponential probability function has the property that the expected value for the arithmetic mean of any right hand segment of the curve is always the same provided that the axis is adjusted so that the starting point of the selected segment is zero. The curve is trimmed dynamically each time a new rate is calculated. An individual count of strike events is kept for N separate but consecutive time units, and the counts for the later occurring events are lumped together as the Main Event. After the data collection period ends, a total accumulated time and accumulated count are constructed. This construction begins by examining the Main Event data.

Abstract: A device for measuring nuclear radiation which comprises a scintillator (10) for the detection of the radiation quanta which is optically coupled to an entrance window of a photodetector (20) for converting the scintillations produced by the radiation into current pulses. The device comprises a digital circuit which is connected to a sampling and analog-to-digital conversion circuit (40) and which is used to determine the energy of each nonsuperposed radiation quantum; when the radiation quanta produce partly superposed current pulses, this circuit determines the energy content of the individual radiation quanta by extrapolations and corrections, notably by means of a memory (170 and/or 180) in which the correction coefficients are stored for performing extrapolations and corrections under the control of a sequencer (200) as initiated by a pulse edge detector (80) which detects the incidence of a radiation quantum.

Abstract: In a method of reading out a radiation image stored in a stimulable phosphor sheet by scanning the stimulable phosphor sheet by stimulating rays, preliminary read-out and final read-out are conducted. The read-out line density of the stimulating rays in the final read-out is detected in advance. Image read-out conditions and/or image processing conditions adjusted on the basis of image information obtained by the preliminary read-out are corrected in accordance with the read-out line density in the final read-out so that the same final read-out image information and/or the same image signal after image processing is obtained from the stimulable phosphor sheet carrying the same image information stored therein.

Abstract: An apparatus for detecting iodine isotopes in the exhaust gas of a nuclear installation includes a duct for a partial exhaust gas stream, which duct includes an absorption chamber which is disposed in a radiation shielding structure and through which the exhaust gas flows and which has associated therewith means for admitting absorption material and for removing it therefrom. Radiation detectors are supported in the radiation shielding structure at opposite sides of the absorption chamber for monitoring radiation of iodine isotopes collected therein, the cavity in the shielding structure in which the absorption chamber is disposed being larger than the absorption chamber and the absorption chamber being supported so as to be movable in the cavity relative to said detectors to permit calibrating the apparatus.

Abstract: A multispectral collimator for testing and verifying electro-optical and opto-mechanical parameters of a forward looking infrared receiver, laser receiver, laser transmitter and the like. The collimator having a plurality of sub-systems which can be readily repositioned to test different types of electro-optical systems of a unit under test.

Abstract: Earth formations penetrated by a borehole are irradiated with pulses of fast neutrons. The epithermal neutrons resulting from moderation of the fast neutrons are detected in a plurality of time intervals to determine the porosity of the adjacent earth formations independently of lithology. Borehole effects are taken into account by separately determining borehole and formation epithermal neutron decay constants.

Abstract: A method is disclosed for the simultaneous determination of borehole (11) and earth formation (20) thermal neutron decay time components. The method, which employs pulsed high energy neutron sources (21) and time gated detectors (23,24), furnishes several quality indicators, along with appropriate criteria for selecting which to use. The method also furnishes a new indicator for the borehole capture cross section.

Abstract: A device for the handling and protection of canisters for storing radioactive materials is described, which are encapsulated by a shock sensitive corrosion resistant cladding hull. The lower and upper edge areas of the canisters are covered by guard caps which are held in place during handling by lifting bars connected to a lifting plate.

Abstract: A device for attaching a collimator to a radiation detector. A number of cleats are mounted at the radiation detector for cleating the collimator to the radiation detector and a latch means serves for latching the cleated collimator against rotation. Also a collimator cleating detection means is associated with the cleat means for detecting incorrect cleating of the collimator and a collimator latch detection means is associated with the latch means for detecting incorrect latching of the collimator.