Abstract: In a corona charger of the scorotron type, a corona wire is detachably secured to a base frame made of insulating material and a control grid is also detachably secured to a grid frame made of insulating material. The grid frame is secured to the base frame in an easily removable manner. The control grid is resiliently stretched over an opening of the grid frame by means of a coiled spring. The corona wire can be easily cleaned or replaced without removing the control grid from the grid frame, and the control grid can be also simply cleaned or replaced without removing the corona wire from the base frame.

Abstract: A method and apparatus for evaluating the performance of diagnostic x-ray systems. The method consists of using an x-ray generator under standard conditions and making a test x-ray film, for example, of the dental intra-oral type and comparing its density with a calibrated step density strip, using a test tool member consisting of a sleeve-like body with opaque parallel flat top and bottom walls receiving the step density strip slidably therebetween. The flat walls have registering transverse rectangular windows, in the forward parts of which can be exposed a selected density step. The rear portion of the body, between the flat walls, has spacer blocks defining therebetween a transverse channel overlapped by the windows through which the test x-ray film can be inserted to compare its density with that of the selected step density. This can be utilized to determine if the test film density is within an optical density in a desired range including certain steps of the calibrated density strip.

Abstract: The formation of lines of the order of 8 Angstroms wide is achieved using a tunneling current through a gas that changes to provide a residue that is the basis of the line. The tunneling current energy is tuned to the energy required to dissociate the gas.

Abstract: The invention relates to a diagnostic radiology setup with means for suppressing stray radiation and with an image intensifier television chain with image storing means. There is provided a perforated diaphragm of radiation-absorbing material near the tube, which diaphragm can be introduced into the ray path selectively. Two image memories for an X-ray picture with a diaphragm and an X-ray picture without a diaphragm and an image processing system serve for comparing the image information of the two X-ray pictures to determine and eliminate the stray radiation component.

Abstract: A device for directly displaying X-ray images on a phosphor screen of a cathode ray tube by means of a steady cathodoluminescence is arranged such that the excitation of the phosphor screen is controlled by the persistent polarization and depolarization of the phosphor crystals in the phosphor screen by exposure to X-rays. The X-ray images formed on the phosphor screen in the cathode ray tube may be read out by synchronously detecting changes in the electric current of the collecting electrodes of the tube during the scanning of a reading electron beam on the phosphor screen displaying the X-ray images.

Abstract: A mixture of H.sub.2 O, CO.sub.2 and CO are measured in the same sample chamber by infrared radiation passing through the chamber and absorption filters passing a narrow band in their respective absorption curves to an infrared detector. Background radiation is zeroed by grounding the detector response when an opaque segment is disposed in the path. A reference filter detects drift which is automatically corrected.

Abstract: The patient's ECG signal is employed in a traverse-and-rotate type CT scanner as a time base for triggering the beginning of a traverse such that the traveling beam reaches the heart at a desired phase of the cardiac cycle. For a purely-rotational-type CT scanner, continuously generated scan data is only stored for corresponding phases of successive cardiac cycles. Alternatively, gating of the beams themselves can be controlled by the ECG signal. The use of a pacemaker to stabilize the cardiac period is described along with a system for recognizing unacceptable variations in the cardiac period. In a traverse-and-rotate-type fan-beam CT scanner, the effective beam width is narrowed to hasten the traverse of the heart.

Abstract: A two-dimensional X-ray detecting apparatus is comprised of an amorphous silicon layer for trapping electrons in a pattern corresponding to an intensity distribution when it is receiving X-rays, and a scanning device for scanning the surface of the amorphous silicon layer with a laser beam to take out electrons trapped in the silicon layer.

Abstract: A thermoluminescence dosimeter having a very small rate of decline of sensitivity during subsequent uses after heating is disclosed. The dosimeter includes a detector crystal and a glass enclosure in which the detector crystal is located. The glass enclosure is air tight and is filled with a super dry inert fill gas. The inert fill gas is nonreactive with the detector crystal when the detector crystal is heated to thermoluminescence. The fill gas is selected from the group consisting of air, nitrogen, and argon, suitable admixed with 5 to 25 percent helium. The detector crystal consists essentially of calcium fluoride. The fill gas is preferably contained at a subatmospheric pressure in the glass enclosure.

Abstract: In an X-ray analysis apparatus, a pulse amplitude shift correction circuit is provided for producing correction signals which are a measure of pulse amplitude shifts and which are in response to the pulse amplitude shifts. This circuit provides automatic correction of pulse amplitude shifts so that the pulse amplifier of the device is controlled.

Abstract: The invention provides a device for measuring ionizing radiations, comprising a Geiger-Muller tube (1) whose high supply voltage is obtained from pulses which are emitted (by 6,7) at a constant relatively low frequency as long as a predetermined threshold is not exceeded by the intensity of the radiation and (by 6,7,4 and 32) at an increasing frequency depending on the output of the tube, after said threshold has been exceeded. Thus, alarm dosimeters having very long independent operation may be formed.

Abstract: The potassium chloride concentration of a drilling fluid is monitored during well drilling operations to identify any depletion in such concentration with time. Initially, the gamma radiation measuring apparatus utilized is calibrated by making gamma radiation measurements on self-shielded drilling fluid samples having successively increasing potassium chloride concentrations. A calibration constant is derived from the measured relationship between the potassium chloride concentrations of the various drilling fluid samples and their respective gamma radiation count rates. This calibration constant is then used along with the measured gamma radiation count rates from drilling fluid taken during well drilling operations to identify drilling fluid potassium chloride concentration.

Abstract: An improved method and apparatus for energy window selection in a radiation signal processing system which in a preferred embodiment includes obtaining energy level histograms corresponding to corrected spatial elements and determining a standard count of radiation events to be accepted by each true spatial element in response to a flood image. The energy window of each corrected spatial element is then adapted to cause each to accept the standard count of radiation events in response to a flood image whereby greater uniformity of image may be accomplished in the imaging process.

Abstract: The apparatus, which may be an electron beam column, has a lens system for coarse- and fine-focus adjustments of the beam. The coarse-focus is effected by a magnetic lens (10) and the fine-focus by an electric lens (14) in parallel with the magnetic lens. The electric lens may comprise a plurality of electrically conductive cylinders (14a to 14d) inside the magnetic lens. The cylinders are so arranged that, by applying appropriate potentials to them, fine-focus adjustments can be carried out without causing the beam to rotate.

Abstract: A charged particle energy analyzer comprises a source for generating radiation to be incident on a sample so as to emit charged particles from the sample, a low energy pass reflection filter for selectively reflecting the charged particles having energy lower than a first value, a high energy pass transmission filter for selectively transmitting the charged particles having energy higher than a second value. The low energy pass reflecting filter comprises a reflector and a first grid. The reflector is a spheroid mirror having two complex focuses, disposed in a symmetrical manner, at which the sample and a detector are disposed. The detector detects the selected charged particles.

Abstract: An infrared (IR) illuminator indicator which has a fiber optics light guide hat channels the IR radiation from an IR radiation source in the illuminator to the faceplate of an image tube as an indicator mark. The image tube converts the IR radiation to the visible spectrum. If the operator of the image tube attempts to operate the IR illuminator at large ranges, or if a near target is suddenly removed so that the IR radiation suddenly reached a much larger range, the image tube gain will suddenly increase to compensate for less reflected radiation. With the fiber optics light guide channeling a constant amount of IR radiation from the IR radiation source to the input of the faceplate, the enhanced gain of the image tube automatically brightens the indicator mark to the observer of the image tube and thus indicates the need to immediately turn off the IR radiation source to avoid detection by the enemy.

Abstract: A magnetic lens for imaging and rotation of a charged particle beam includes a pair of focus elements axially spaced along a lens bore through which the beam passes and a rotation element positioned axially between the focus elements. Each of the lens elements includes a polepiece having opposing portions surrounding the lens bore and axially spaced apart to define a circumferential gap, and a winding for energizing the polepiece and the gap. The focus elements are energized by equal and opposite magnetic fields which focus the electron beam without substantial beam rotation. The beam can be rotated, without substantial change in focus or magnification, by varying the magnetic field of the rotation element. The lens is particularly suited for use in a shaped electron beam lithography system.

Abstract: For use in a nuclear well logging tool, detector pulse simulator circuits in the preferred and illustrated embodiments are set forth. The simulator circuit is adapted to be placed in a sonde for connection with a well logging tool to provide simulated detector pulses. It is selectively switched on to the output a calibrated pulse sequence function through a number of different levels. It incorporates a circuit means forming pulses limited in amplitude by an envelope yielding pulses of differing amplitude in progression. The circuit is stepped repetitively through its range of operation, for example, from a minimum voltage peak to some specified maximum and then recycles.

Abstract: Leaks in natural gas pipelines are detected by an airborne gas cell correlation radiometer having two channels, one to detect methane and the other to detect nitrous oxide. The channel outputs are compared in order to detect anomalies in their relative magnitude, an increase in methane concentration relative to nitrous oxide concentration being indicative of a gas leakage in the area from which the radiometer receives radiation.

Abstract: A highly sensitive and compactly structured radiation measuring instrument for detecting ionizing radiation, in particular for measuring dose rates and contamination.The laminar structure of the associated counter tube, using only a few, simple plastic parts (1, 8, 9) and a highly elastic counter wire (2), makes it possible to use the simplest manufacturing techniques. The service life of the counter tube construction, which is completely and permanently sealed and filled with gas, is expected to be more than 12 years.The described counter tube can be adapted in optimal fashion to the available space in a pocket instrument if it is used in combination with a specialized high-voltage generator which is low in interference voltage and with a pulse evaluation circuit having a means of compensating for interference voltage.