Abstract: A step-up circuit includes a transistor configured to perform switching operation in response to a pulse signal input into a base of the transistor, an inductor disposed between a collector of the transistor and a power source, and a basic step-up circuit connected to a connecting point of the collector of the transistor and the inductor. The basic step-up circuit includes: a first diode, a second diode whose anode is connected to a cathode of the first diode, a third diode whose anode is connected to a cathode of the second diode, a first capacitor disposed between the cathode of the first diode and ground, a second capacitor disposed between an anode of the first diode and the cathode of the second diode, and a third capacitor disposed between a cathode of the third diode and the ground.

Abstract: An electron generating device extracts electrons, through an electron sheath, from plasma produced using RF fields. The electron sheath is located near a grounded ring at one end of a negatively biased conducting surface, which is normally a cylinder. Extracted electrons pass through the grounded ring in the presence of a steady state axial magnetic field. Sufficiently large magnetic fields and/or RF power into the plasma allow for helicon plasma generation. The ion loss area is sufficiently large compared to the electron loss area to allow for total non-ambipolar extraction of all electrons leaving the plasma. Voids in the negatively-biased conducting surface allow the time-varying magnetic fields provided by the antenna to inductively couple to the plasma within the conducting surface. The conducting surface acts as a Faraday shield, which reduces any time-varying electric fields from entering the conductive surface, i.e. blocks capacitive coupling between the antenna and the plasma.

Abstract: An economical position-sensing muon detector for muon radiography is constructed using a pair of glass plates spaced apart by crossed parallel barriers. Smaller detector wires are interspersed between the barriers and an ionizing gas is used to fill the space between the plates. A muon striking near where detector wires cross causes a local momentary current flow. The current flow in two of the detector wires is sensed to determine the coordinates of the muon impact. Such muon detectors can be assembled in modular surface arrays and such arrays can be positioned on spatial surfaces for differential inspection and detection of muons transiting through and emanating from objects placed within the inspection space. Such a detector constitutes a novel and useful invention in providing an inspection device and means for cargo or cargo vehicles that detects muons transiting through and emanating from hazardous materials intended to cause malicious harm.

Abstract: A radiation detector, comprising a sensitive volume filled with a counter gas; an anode and a cathode each in communication with the counter gas; a voltage supply for maintaining a potential difference between the anode and the cathode, said potential difference being less than required to cause gas discharge in the counter gas. The radiation detector further comprises a photoemissive material in communication with the sensitive volume. The photoemissive material may be provided as a coating on the cathode. The radiation detector may further comprise a controllable light source for supplying photons of a known wavelength to the photoemissive material. Electrons may be emitted by the photoemissive material in response to the provision of said photons, said electrons causing avalanche breakdown of the counter gas, indicating satisfactory operation of the radiation detector.

Abstract: An ion detector 7 for a mass spectrometer is disclosed comprising a microchannel plate 8 which receives ions 12 at an input surface and releases secondary electrons 16 from an output surface. A detecting device 9 having a detecting surface is arranged to receive at least some of the electrons 16 emitted by the microchannel plate 8. The area of the detecting surface is substantially greater than the area of the output surface of the microchannel plate 8.

Abstract: A radiation detector that utilizes an unregulated power supply as opposed to a regulated power supply, since quantitative results are not required, only an audible signal, and an unregulated power supply is less expensive than that of a regulated power supply. The radiation detector includes a Geiger-muller tube, a nine volt DC power supply, a solid state oscillator with an output of 2 kilohertz, a high voltage power supply, and an audio amplifier.

Abstract: Bradbury-Nielson gates for the modulation of beams of charged particles, particularly ion beams in mass spectrometry, have been produced with an adjustable wire spacing down to 0.075 mm or a smaller spacing. The gates are robust, they can be fabricated in less than 3 hours, and the method of production is reproducible. In time-of-flight mass spectrometers, fine wire spacing leads to improvements in mass resolution and modulation rates. Gates that were produced using this new method have been installed in a Hadamard transform time-of-flight mass spectrometer in order to demonstrate their utility.

Abstract: A device for measuring a total concentration of impurities in a sample gas is provided which includes a housing having an inlet to allow the sample gas to enter the housing, an emitter to generate ions from the sample gas, a field gradient to accelerate the ions toward a collector, the collector adapted to measure total ions, and an outlet to allow the sample gas to exit the housing, whereby a change in total ions received by the collector indicates a change in the total concentration of impurities in the sample gas.

Abstract: A method and apparatus for monitoring alpha contamination are provided in which ions generated in the air surrounding the item, by the passage of alpha particles, are moved to a distant detector location. The parts of the item from which ions are withdrawn can be controlled by restricting the air flow over different portions of the apparatus. In this way, detection of internal and external surfaces separately, for instance, can be provided. The apparatus and method are particularly suited for use in undertaking alpha contamination measurements during the commissioning operations.

Abstract: An alternating electromagnetic field in the radiofrequency range is applied in a gaseous environment (4). Free electrons produced in the gas (4), by an ionising source of radiation (5) or by interaction of a charged particle beam with a specimen, are acted upon by the alternating electromagnetic field and undergo an oscillatory motion resulting in multiple collisions with the gas molecules or atoms. Amplified electron and photon signals are generated in a controlled discharge, proportional to the initial number of free electrons, and are collected by suitable means (6, 7, 8). The alternating field is generated either by electrodes (1, 2) biased with an alternating voltage, or by a coil driven by an AC current, and may be superposed with a static electric field. The detection device may be used with instruments such as electron microscopes, in ion beam technologies, and with instruments used for detection of ionising radiations such as proportional counters.

Abstract: The apparatus and method provide a technique for more simply measuring alpha and/or beta emissions arising from items or locations. The technique uses indirect monitoring of the emissions by detecting ions generated by the emissions, the ions being attracted electrostatically to electrodes for discharge of collection. The apparatus and method employ a chamber which is sealed around the item or location during monitoring with no air being drawn into or expelled from the chamber during the monitoring process. A simplified structure and operations arises as a result, but without impairing the efficiency and accuracy of the detection technique.

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: Disclosed is a picture information memory device, including a picture information memory means for generating electric charges corresponding to the intensity of write-in light incident thereon, and for holding the generated electric charges as polarized charges, an exposing means for exposing the picture information memory means to light from an object, and an alternating-current bias voltage applying means for applying an alternating-current bias voltage having a desired frequency to the picture information memory means, whereby electric charges generated by the portion of the object light the intensity of which varies at the same frequency as that of the alternating-current bias voltage, are selectively accumulated from the entirety of electric charges generated by the object light incident on the picture information memory means, and held as the polarized charges in the picture information memory means.

Abstract: The invention relates to detectors of ionizing radiation which use a photoconductor as the detecting element. The invention lies in an electrode moving in a direction OX through a photoconductive medium disposed between two grids of electrodes extending parallel to OX. During the irradiation time, the grid electrodes of one grid are raised to a positive potential relative to the electrodes of the other grid and electrons and positive ions are created in the photoconductor. The electrons are removed by maintaining the positive potential on the electrodes of said one grid for a period of time longer than the irradiation. During displacement of said moving electrode, only the positive ions give rise to current in the electrodes. The invention is applicable to radiotherapy and radiography.

Abstract: An ionization chamber can stably measure a weak ionizing radiation with high sensitivity. The ionization chamber comprises an electrically conductive charge collecting electrode having a magnetic substance or a permanent magnet; an electromagnet for positioning the charge collecting electrode in non-contact with the other part of the ionization chamber; a position sensor for detecting the position of the charge collecting electrode; a circuit for feedback-controlling the magnetic force of the electromagnet to maintain the charge collecting electrode at the substantially same position; and ionization current detecting circuit for detecting an ionization current collected at the charge collecting electrode by ionization due to radiation applied to the ionization chamber.

Abstract: An optical ionizing radiation detector system (10) for determining the three-dimensional spatial distribution of all of the secondary electrons produced by the passage of ionizing radiation through a selected gas is provided. The detector system (10) can be used over a wide range of particle energies and gas pressures. The ionizing radiation passing through the gas produces prompt fluorescence and secondary electrons. A coincidence detector (30) recognizes coincident events of prompt fluorescence in the gas contained within that chamber to initialize the system cycle. At that time, an AC electric field is generated by an R.F. pulse generator (40) to localize the secondary electrons proximate their respective positions of production. Cameras (42) and 42'), preferably of a digital type, produce an image of the localized electrons to determine their three-dimensional spatial positions.

Abstract: A detector for airborne alpha radiation includes a ion pulse collecting chamber connected to a phase shifted, 100% negative feedback electrometer circuit. The ion pulse chamber includes a probe surrounded by an 80% open grid, with the spacing between the probe and the grid providing no greater than about 50 ms transit time before collection and having a capacitance of less than 1 pf. The field strength between the probe and the grid is less than 10 V/cm. The ion pulse chamber is contained within a vented cabinet. If it is desired to count only radon, a negative potential with respect to the grid may be applied to the cabinet to collect positively charged free ions. Alternatively, the cabinet wall can be made positive with respect to the grid to create a potential-well at or near the grid to provide an enhanced daughter detection mode. If the cabinet wall and the grid are the same potential, both radon and daughter alpha radiation are detected.

Abstract: A personal radiation monitor of the chirper type is provided for detecting ionizing radiation. A battery powered high voltage power supply is used to generate and apply a high voltage bias to a G-M tube radiation sensor. The high voltage is monitored by a low-loss sensing network which generates a feedback signal to control the high voltage power supply such that the high voltage bias is recharged to +500 VDC when the current pulses of the sensor, generated by the detection of ionizing radiation events, discharges the high voltage bias to +450 VDC. During the high voltage recharge period an audio transducer is activated to produce an audible "chirp". The rate of the "chirps" is controlled by the rate at which the high voltage bias is recharged, which is proportional to the radiation field intensity to which the sensor is exposed. The chirp rate sensitivity is set to be approximately 1.5 (chirps/min/MR/hr.).

Abstract: A discharging element energizing circuit for a discharge-type fire alarm sensor unit including a discharging element, wherein a power supply circuit gives a power voltage to the discharging element in the form of periodical output pulses making same ready to discharge and a feedback circuit is provided to supply a feedback signal obtained from the discharging element to the power supply circuit so as to vary the interval of the output pulses. The sensor unit is continuously sensitive to ultraviolet rays only caused by a fire disaster, thus preventing a malfunctional alarm. Power consumption is reduced considerably, allowing the unit to be operated with commercially available dry cells.

Abstract: A device for measuring local X-ray absorption differences in a patient or other object has an array of ionization detector elements. Each detector element has a high voltage electrode. The high voltage source for each such electrode has associated with it an alternating voltage source in order to compensate for microphonic interference. The measuring circuit includes a demodulation compensation circuit for separation of the microphonic signal and for removing this interference from the measuring signal.