Abstract: A photoionization detector includes a housing, electrical contacts within the housing and an easily removable and replaceable photoionization chamber within the housing. The photoionization chamber includes a cathodic electrode and an anodic electrode which may be coated with a thin layer of material. The photoionization chamber and the associated cathodic electrode and anodic electrode are removable from within the housing as a unit. The photoionization chamber makes electrical connection with the contacts when seated within the housing regardless of the orientation of the photoionization chamber about an axis.

Abstract: A radiation detector for imaging a sheet-shaped beam (11) of ionizing radiation comprises an electron multiplication chamber (12) filled with a medium for electron multiplication; and a solid multichannel structure (14) arranged in the path of the sheet-shaped beam within the chamber, wherein the structure liberates electrons (16a) in response to being exposed to the radiation. An electron detecting means (17d) is provided for detecting the electrons spatially resolved to thereby image the sheet-shaped beam. The structure (14) is of a scintillating material, so that said the structure emits scintillating light in response to being exposed to the radiation; and detecting means (19–20) are provided for detecting scintillating light (18) emitted from the structure.

Abstract: A spectrometer system employs a gridless Xenon detector having an anode and a cathode supported in spaced relation from the anode devoid of structure intermediate the anode and cathode. Pulses resulting from charge collection due to radiation ionization of the Xenon gas are detected and parametrized by a computation engine through multiple detected pulses. Simultaneous determination of the position and ionization energy allows selective presentation of the data to compensate for various position dependent phenomena.

Abstract: An arrangement for emitting light includes a hermetically sealed casing with a window, a layer of a fluorescent substance arranged within the casing covering at least a major part of the window, an electron emitting cathode arranged within the casing, and an anode. The casing is filled with a gas suitable for electron avalanche amplification. In operation, the cathode and anode are held at an electric potential such that said emitted electrons are accelerated and avalanche amplified in the gas. The layer of the fluorescent substance is arranged to emit light through the window in response to avalanche amplified electron bombardment and/or ultraviolet light emitted from the gas.

Abstract: An ionized alpha particle detector to directly measure alpha activity in ambient air that counts alpha pulses instead of measuring radon concentration is provided by an open-air ionization chamber, a means for collecting ions, a voltage source, a charging means and a means for recording alpha pulses. The ionized alpha particle detector allows the user to directly measure the alpha particle activity in ambient air and consequently, better assess the radiological public health risk from alpha particles emitted by inhaled air. The ionized alpha particle detector advantageously overcomes the difficulties in measuring alpha particles caused by oxygen ions that quickly attract electrons and form negative ions that compensate positive charged particles and prevent the formation of alpha particle pulses.

Abstract: A voltmeter for measuring atmospheric or other voltages eliminates the dead band without application of high voltages or radioactive isotopes to increase conductivity in the region of the probe. A vacuum tube is operated at substantially reduced conduction in order to achieve high sensitivity and eliminate passive components in the input circuit. A voltage is developed to produce meter indication or control charging or charge-neutralizing circuits. In the preferred embodiment, a meter scale is calibrated to indicate the presence of atmospheric charges of particular interest to anglers. Naturally occurring electrical currents are known to stimulate the feeding of fish.

Abstract: A voltmeter for measuring atmospheric or other voltages eliminates the dead band without application of high voltages or radioactive isotopes to increase conductivity in the region of the probe. A vacuum tube is operated at substantially reduced conduction in order to achieve high sensitivity and eliminate passive components in the input circuit. A voltage is developed to produce meter indication or control charging or charge-neutralizing circuits. In the preferred embodiment, a meter scale is calibrated to indicate the presence of atmospheric charges of particular interest to anglers. Naturally occurring electrical currents are known to stimulate the feeding of fish.

Abstract: A coating material (20) for coating a machine component (10), especially a gas turbine or a part thereof, comprises a mixture of at least a refractory material and an indicator material having an optical emission (e.g. fluorescence) spectrum which varies in response to a physical parameter of the coated component. In a preferred embodiment, the coating consists of yttrium aluminium garnet (YAG) or yttrium stabilised zirconium. The dopant is preferably a rare earth metal, e.g. Eu, Tb, Dy.

Abstract: A photo-ionization detector having an adjustable drive power for a UV lamp implements a calibration operation that determines measurement signals for a series of drive power levels and based on the resulting measurement signals selects one or more drive power levels for normal operation of the PID. The calibration operation permits use of UV lamps having a wider range of performance levels and thereby improves manufacturing yields and extends the useful life of the PID. During normal operation, the PID further fine-tunes the drive power level to compensate for expected or measured degradation in lamp performance. Accordingly, between calibrations, the PID maintains a more uniform UV intensity for more accurate measurements. To expand the measurement range of the PID, the calibration process can select two or more power levels for use when measuring different gas concentrations.

Abstract: Devices are disclosed that incorporate an ionization device for generating ions and electrons having first and second conductive electrodes that are separated by less than the mean-free-path of molecules being ionized. Electrons generated by the ionization device may be used for applications such as light sources, electron bombardment sensors, thyratrons, vacuum tubes, plasma displays, and microwave switches, and ions generated by the ionization device may be used, inter alia, in connection with ion focused milling devices, maskless ion implantation devices, ion beam lithography devices, semiconductor mask modification devices, and semiconductor chip wiring devices. Methods of use and manufacture are also provided.

Abstract: The cool air inside a refrigerator compartment 2 is introduced through a return opening 10 into an ion generation chamber 45 provided behind the refrigerator compartment 2. A voltage is applied to a needle-like electrode 11a arranged in an upper portion of the ion generation chamber 45 so that, by corona discharge, positive and negative ions are discharged substantially parallel to the cool air circulating in the direction indicated by arrow B2. This helps alleviate the loss of ions resulting from collision with a wall surface, and permits the ions to reach a wide area. This prolongs the period for which the cool air is kept in contact with the ions, and thus helps enhance the sterilizing effect.

Abstract: An ion trap mobility spectrometer is provided. The ion trap mobility spectrometer employs algorithms to simultaneously detect and analyze both positive and negative plasmagrams. Selectivity is improved by detecting the presence of peaks in both spectra and setting logic filters which require the presence or absence of certain peaks in both spectra. Selectivity is improved by looking for two peaks in the two spectra.

Abstract: The cool air inside a refrigerator compartment 2 is introduced through a return opening 10 into an ion generation chamber 45 provided behind the refrigerator compartment 2. A voltage is applied to a needle-like electrode 11a arranged in an upper portion of the ion generation chamber 45 so that, by corona discharge, positive and negative ions are discharged substantially parallel to the cool air circulating in the direction indicated by arrow B2. This helps alleviate the loss of ions resulting from collision with a wall surface, and permits the ions to reach a wide area. This prolongs the period for which the cool air is kept in contact with the ions, and thus helps enhance the sterilizing effect.

Abstract: A sensor for detecting volatile organic compounds in ambient air by positioning a detection cell adjacent a gas discharge device to cause molecules of organic compounds to become ionized, and applying an electric field across the collection cell to attract ions and free electrons formed in the cell to develop a current, and amplifying the current magnitude so created.

Abstract: A monitor that can detect a trace molecule that is ionized at approximately one atmosphere. The molecule is ionized with a photoionizer and detected by a detector. The monitor may include a number of techniques to introduce a sample into the photoionizer at approximately one atmosphere. One technique includes creating an electrically charged spray that is directed into the ionizer. The photoionizer may include a plurality of light sources that each ionize the sample with a different radiation energy.

Abstract: A system for sampling the ambient air of a selected environment for the presence of unwanted chemical vapors, such as nerve or blister gases includes an external air sampling unit and a detector unit having first and second ion mobility spectrometers which simultaneously detect and monitor for the presence of the chemical agent vapors so as to provide an accurate and quick determination of the unwanted chemical vapor within the selected environment.

Abstract: A soft ionization device is disclosed that comprises a series of electrodes having pacing less than the means free path of the molecules to be ionized. In some embodiments, the soft ionization device is used in various applications that require ion or electron sources such as biological or chemical reactors, ion milling, and numerous replacements for conventional hot cathode systems. In another embodiment, a valence spectrometer is disclosed that is configured to variably ionize molecules by their valiancy. In other embodiments, the ionization device is coupled to a spectrometer for the characterization of biological matter. Also disclosed is a preconditioner for preparing biological matter to be ionized.

Abstract: A gaseous supply system and method for operating the same is disclosed for supplying at least one gaseous source material to an ion source chamber for use with an ion implanter including at least one gas supply module in gaseous communication with an ion source chamber including at least one pneumatic valve to control the delivery of at least one gaseous source material to the ion source chamber for generation of source material ions for implantation including a driver gas source in communication with said at least one pneumatic valve for operating the at least one pneumatic valve said driver gas source having a different atomic mass unit than the source material ions for implantation generated from the at least one gaseous source material.

Abstract: A design and readout of a xenon detection medium based device, which provides improved spectroscopic performance compared to currently commercially available devices. To achieve energy resolution improvement, a method to accurately measure radial spatial position for interacting events within a HPXe cylindrical detector is described using the plan as shown in FIG. 4. This is accomplished by utilization of light generated both at the gamma interaction site and at the collection point near the anode wire of the cylindrical detector. These light flashes are detected by a VUV photon detector. Light transmission is facilitated by incorporating a vacuum ultraviolet (VUV) light transparent window at least one end of the cylindrical ionization detector. With the known electron drift velocity in HPXe, the time between these two photopulses is sufficient to accurately determine the radial coordinate. Consequently, correction by electronic means for the electrostatic pulse dispersion using the expression graphed in FIG.

Abstract: A neutron flux measuring apparatus, adapted to a boiling-water reactor (BWR) of a nuclear power plant and an advanced boiling-water reactor (ABWR) of a nuclear power plant, for measuring a neutron flux in a reactor pressure vessel, comprises a neutron flux detector assembly incorporating a local power range monitor detector assembly and a start-up range neutron monitor detector, a preamplifier amplifying a detector signal obtained from said start-up range neutron monitor detector, a start-up range neutron monitor operation unit operating, indicating and monitoring the amplified signal of the start-up range neutron monitor detector, and a local power range monitor operation unit operating, indicating and monitoring a signal obtained from the local power range monitor detector.

Abstract: A detector for detection of ionizing radiation, an apparatus for use in planar beam radiography, comprising such a detector, and a method for detecting ionizing radiation.

Abstract: A contact interface having a substantially annular silicide ring along sides of a depression formed in an active surface of the semiconductor substrate, wherein the depression is formed by an etching process to form a contact opening through a dielectric layer. The contact interface is formed by depositing a layer of conductive material, such as titanium, with a high bias power IMP deposition. The conductive material is turned to a silicide by an annealing process, thereby forming the contact interface.

Abstract: A multiple-channel photo-ionization detector (PID) determines the concentrations of specific gases or classes of gases. The PID includes a UV lamp, an optical window which is divided into multiple zones with each zone producing a UV light beam having a distinctive maximum photon energy. The ionization chamber of the PID includes multiple ion detectors. The PID measures ionization currents and concentrations of gases ionizable by each UV light beam. A method of determining the concentrations and/or identifications of the individual component gases uses differences and/or ratios of measured concentrations or currents.

Abstract: The radometer is a portable instrument for the measurement of the concentration of atmospheric radon/thoron in a test area. A constant velocity pump pulls the air from the outside at a constant flow rate. If the air is too moist, some or all of the sample is passed through a desiccant filter prior to encountering an electrostatic filter. The electrostatic filter prevents any charged particles from entering the sampling chamber. Once the sample has entered the chamber, the progeny of the decay of radon/thoron are collected on a detector and measured. The measured data is compiled by a computer and displayed.

Abstract: A dynamic focusing apparatus is comprised of a parabaolic voltage generating device for generating a parabolic voltage VpbI across a capacitor 9M by applying a horizontal flyback pulse a series circuit of an inductor 8 and the capacitor, a coupling device 10 for supplying the parabolic voltage to a focus electrode "f" of a cathode-ray tube, the capacitor which includes a plurality of capacitors 9S, an electronic switching device 11 for selectively connecting some of the plurality of capacitors for a time duration corresponding to an approximate center of a horizontal period and for disconnecting the some of the plurality of capacitors for other duration, and a switching control device for controlling the electronic switching device.

Abstract: Gas pressure in a chamber is determined by injecting alpha particles. The alpha particles ionize the gas. By determining a number of gas ions which are ionized, the pressure of the gas in the chamber can be determined.

Abstract: A penning type gauge head with an electrode system comprising an anode and a cathode disposed in the magnetic field of a permanent magnet, including an ignition aid for the electrode system. In order to provide rapid and reliable ignition, the ignition aid consists of a least one metal strip attached on the anode, and the free end of the ignition aid extends in the direction toward the cathode.

Abstract: An ionization detector having an upper ionization chamber, a lower ionization chamber, and a radioactive source located in the upper ionization chamber but shielded from the lower ionization chamber by a barrier. A substantially constant fluid stream of detector gas is supplied to the upper ionization chamber so as to fill the upper ionization. The radioactive particle emitter is disposed on the periphery of the interior of the upper ionization chamber so as to generate a constant supply of alpha particles into the internal volume defined by the upper ionization chamber. The interaction of the alpha particles and the detector gas generates metastables and photons as the alpha particles traverse a portion of the volume in the upper ionization chamber. The lower ionization chamber is coupled to the upper ionization chamber so as to receive the detector gas flow and the metastables.

Abstract: A radiation monitor for use with liquids that utilizes air ions created by alpha radiation emitted by the liquids as its detectable element. A signal plane, held at an electrical potential with respect to ground, collects these air ions. A guard plane or guard rings is used to limit leakage currents. In one embodiment, the monitor is used for monitoring liquids retained in a tank. Other embodiments monitor liquids flowing through a tank, and bodies of liquids, such as ponds, lakes, rivers and oceans.

Abstract: Method of quantitatively detecting material in a sample, whereby the material is in the form of submicrometric particles covered by a photoemitting substance, and a device for practicing the method. The material in the sample is heated to a photoemitting state and subjected while in that state to photoemission measurement. The proportion of material in the sample is determined from the signal obtained from that measurement by comparison with empirical data obtained from a reference sample containing a previously detected quantity of the material or by comparison with data obtained for the material by calibration.

Abstract: A photoionization detector includes a brittle substrate having a void micromachined therein with a void inlet and a void outlet. First and second electrodes are disposed in the void. An ultraviolet transparent member covers at least a portion of the void in which the electrodes are disposed. A gas sample passes through the void and is exposed to ultraviolet radiation from a UV source. Ionization of the sample is measured as current flowing between the electrodes.

Abstract: A photo-ionization detector (PID) which measures volatile organic gas uses electrically insulated parallel plates to energize a miniaturized gas discharge UV lamp and an energy efficient method to modulate the UV lamp intensity and reduce power consumption. A miniaturized centrifugal pump is integrated into the PID to provide active sampling for fast response to volatile gas. An ionization chamber in the PID includes a UV shield which protects a measurement electrode from UV light and a UV monitor which measures changes in UV intensity due to external interferences and UV lamp variations. A microprocessor in the PID uses measurements from the measurement electrode and from the UV monitor to accurately account for UV intensity variations when determining a volatile gas concentration.

Abstract: Electron capture detector for use with an effluent stream from a gas chromatograph includes an electron source means and an adjacent ionization chamber in which electron capture takes place. The active region of the ionization chamber is disposed to receive free electrons and a flow of purge gas. The detector has an inlet port for receiving a sample gas as well as an outlet port for exhausting the sample gas and the purge gas. A collector electrode in the detection chamber is biased so as to collect the free electrons in the absence of electrophilic substance. Electrophilic substances in the detector will reduce the flow of electrons to the collector and generate an ionic current. An insulative member in the form of a flow guide may be located at the portion of the anode so as to permit pulsing of free electrons to the anode but substantially block the ionic current, i.e., to discriminate between the free electrons and the ionic current.

Abstract: A Voigt optical filter. Crossed polarizers are provided at the entrance and exit of a vapor cell continuing an alkali metal vapor. A magnet provides a magnetic field at 90.degree. with the axis of the cell and 45.degree. with each polarizer direction. The only light which passes through the filter is light within a narrow frequency band near the atomic transitions (absorption peaks) of the alkali metal vapor.

Abstract: A beta radiation detector which is capable of reliably detecting beta radiation emitted from a surface. An electrically conductive signal collector is adjustably mounted inside an electrically conductive enclosure which may define a single large opening for placing against a surface. The adjustable mounting of the electrically conductive signal collector can be based on the distance from the surface or on the expected beta energy range. A voltage source is connected to the signal collector through an electrometer or other display means for creating an electric field between the signal collector and the enclosure. Air ions created by the beta radiation are collected and the current produced is indicated on the electrometer or other display means.

Abstract: An electrostatic alpha radiation detector for measuring alpha radiation emitted from inside an enclosure comprising an electrically conductive expandable electrode for insertion into the enclosure. After insertion, the electrically conductive expandable electrode is insulated from the enclosure and defines a decay cavity between the electrically conductive expandable electrode and the enclosure so that air ions generated in the decay cavity are electrostatically captured by the electrically conductive expandable electrode and the enclosure when an electric potential is applied between the electrically conductive expandable electrode and the enclosure. Indicator means are attached to the electrically conductive expandable electrode for indicating an electrical current produced by generation of the air ions generated in the decay cavity by collisions between air molecules and the alpha particles emitted from the enclosure.

Abstract: An ionization chamber for use in a smoke detector includes first and second outer electrodes and a non-reflective center electrode. The non-reflective center electrode can be formed as a metal electrode having a non-reflective coating or as a non-reflective, conductive plastic elements. The ionization chamber can be incorporated into combination smoke detector which includes a photoelectric sensor. A non-reflective center electrode, associated with the ion-type sensor is symmetrically located in the detector and displaced from the photoelectric sensor.

Abstract: An improved ionizable gas or vapor detector device and method are provided which are capable in preferred forms of sampling 4.times.10.sup.-3 cubic meters or more of air sec.sup.-1 and are responsive to ionizable gas fluctuations at a rate of up to 100Hz. Use of the device of the present invention has proved to provide sensitivity to UV ionizable gas or vapor of over 500 times that of prior devices, giving detection of propylene tracer gas at concentrations of 2 parts per 1,000,000,000 and thus increasing the range from the gas source at which the device may be reliably used. Use for detection of leaks of volatile UV ionizable compounds and for monitoring processes where vapors are emitted is also provided.

Abstract: A photo-ionization detector utilizes an ultraviolet (UV) lamp and is designed for detecting and measuring the concentration of volatile gases flowing between closely spaced parallel electrodes. One of the electrodes is formed to allow photons to pass into the space between the electrodes to ionize the volatile gases between the electrodes. The detector also incorporates an improved ionization chamber.

Abstract: An electrostatic detector for atmospheric radon or other weak sources of alpha radiation. In one embodiment, nested enclosures are insulated from one another, open at the top, and have a high voltage pin inside and insulated from the inside enclosure. An electric field is produced between the pin and the inside enclosure. Air ions produced by collision with alpha particles inside the decay volume defined by the inside enclosure are attracted to the pin and the inner enclosure. With low alpha concentrations, individual alpha events can be measured to indicate the presence of radon or other alpha radiation. In another embodiment, an electrical field is produced between parallel plates which are insulated from a single decay cavity enclosure.

Abstract: The objective of the invention is a method for detection of alien matter contents in gas, in which method the gas and the substances contained in it are ionized in an ionization room (1). By the present methods impurities in gases cannot be determined fast and in small concentrations. In the method of the invention the ions contained in the gas are separated in a separation section (2) into positive and negative ions, of which at least the ions of either sign are led into a narrow analyzer channel (4). There, due to the capillary force, they are forced to move in the middle section of the channel, from where they are deflected by electric fields of different strength caused by different voltages (U1-U10) into an electrode located at the edge of the channel, where they cause ion current (I1-I10).

Abstract: An improved ECD employing an ECD cell having a third electrode, i.e. guard positioned between the ECD cell field electrodes. The guard electrode is physically interposed between said field electrodes to divert all leakage current in the support insulators which flow between the field electrodes. The guard electrode ECD cell provides improved linear dynamic range as well as avoiding deterioration from handling during manufacture or repair.

Abstract: In the process for investigating particles situated in a gas, a gas stream is guided past a miniaturized UV excimer radiator. In this case, the particles are ionized and subsequently filtered out, and the resultant photoelectrically induced current is measured. Since particles from different sources (petrol engine, diesel engine, cigarette smoke) exhibit a wavelength dependence which is characteristic of the source, by measurements at at least two wavelengths, which is readily possible when using UV excimer radiators with different gas fillings, pollutants can be detected according to the source.

Abstract: A photo-ionization detector utilizes an ultraviolet (UV) lamp for detecting and measuring the concentration of volatile gases flowing between closely spaced parallel electrodes. One of the electrodes is made of mesh to allow photons to pass into the space between the electrodes to ionize the volatile gases between the electrodes. The detector also incorporates an improved ionization chamber. In other embodiments, a plurality of gas discharge lamps, each generating a different photon energy, may be placed adjacent to a plurality of closely spaced electrodes, all electrodes in one ionization chamber, to detect and measure different types of volatile gases that may exist.

Abstract: Controller circuitry and method for controlling the operation of an ionization gauge having a source of electrons, an anode, and an ion collector electrode, including storing a plurality of calibration data sets for at least collector electrode currents and gauge sensitivities obtained with at least one reference gauge at representative values of known pressures; and calculating the gauge sensitivity corresponding to an unknown pressure in response to at least one of the data sets together with a measured value of the ion collector current. The data sets may also include representative values of the heating powers of the electron source so that the calculated sensitivity may also be compensated for variations in the electron source heating power.

Abstract: In a method and a device for measuring the concentration of particles present in a gas, in which a gas stream is guided past a UV light source, the particles are ionized and filtered out and the resulting ionic current is measured, the gas flow required is produced by thermal convection using an internal or external heat source. A suitable internal heat source in this context is, for example, the UV lamp (2) itself, which heats the gas via a radiation absorber (5). The elimination of a mechanical pump reduces the space requirement, power consumption and susceptibility to faults of the measuring arrangement.

Abstract: A cold cathode gauge including a glow lamp or the like disposed within the vacuum space of the gauge for initiating the gauge discharge, the lamp emitting UV or blue light directly at at least the cathode of the gauge where the energy of the light is sufficient to release photoelectrons from the cathode to thus initiate the discharge. A member is also provided for removably positioning the glow lamp within the vacuum space whereby the lamp can be removed during bake out and then subsequent thereto, be inserted within the vacuum space to thus enhance longevity of the lamp.

Abstract: Alpha particle detectors capable of detecting alpha radiation from distant sources. In one embodiment, a voltage is generated in a single electrically conductive grid while a fan draws air containing air molecules ionized by alpha particles through an air passage and across the conductive grid. The current in the conductive grid can be detected and used for measurement or alarm. Another embodiment builds on this concept and provides an additional grid so that air ions of both polarities can be detected. The detector can be used in many applications, such as for pipe or duct, tank, or soil sample monitoring.

Abstract: A method and apparatus for measuring simultaneously the thickness and the composition of a coating on a metal substrate. A first beam of radiation that produces a primary beam of photons is directed substantially perpendicularly to the surface of the coating. A first detector is positioned substantially perpendicularly to the surface of the coating to receive a first fluoresced beam. The photons having a first energy level representing a higher concentration element of the coating are selected. A first electrical signal is provided that is a function of the intensity of the photons having the first energy level. A second beam of radiation producing a second primary beam of photons is directed at an acute angle to the surface of the coating. A second detector is positioned substantially perpendicularly to the surface of the coating to receive a second fluoresced beam. The photons having a second energy level representing a lower concentration element of the coating are selected.

Abstract: A laser radar system capable of measuring windspeed to within 1 m/s at distances in the range of 10 km. The system comprises two fast atomic line filter-detectors, a first filter-detector and a second filter-detector, in which a metal vapor is excited by signal light and further excited to a Rydberg level by a pump laser beam. An electric field is applied to the filters which ionizes the atoms. The filter-detectors operate at one of the resonance absorption peaks of the metal vapor. The second filter-detector is also subject to a magnetic field which splits the absorption peak of the vapor into two absorption peaks leaving a valley in the position of the original absorption peak. A preferred lasing frequency range is a frequency range covering a portion of one of the slopes of the peak of the first filter and a portion of one of the opposite direction slopes of one of the peaks of the second filter.