Abstract: An ionizing system includes a channel having an inlet disposed in a first pressure region and an outlet disposed in a second pressure region, a pressure of the first pressure region being greater than a pressure of the second pressure region. A heater is coupled to the channel and configured to heat the channel. A device is configured to introduce an analyte into the channel where the analyte is ionized.

Abstract: The crystal structure of the emitter can be accurately grasped from a FIM image without being influenced by disturbances, such as contamination, and even if the rearrangement of atoms has been performed, whether or not the crystal structure of the emitter has returned to the original state can also be accurately determined. There is a provided a focused ion beam apparatus including an emitter 10, a gas source 11 which supplies gas G2, a cooling unit 12 which cools the emitter, a heating unit 13 which heats the tip of the emitter, an extraction power source unit 15 which applies an extraction voltage to ionize the gas into gas ions at the tip of the emitter, and then extract the gas ions, a beam optical system 16 which makes the extracted gas ions into a focused ion beam (FIB), and then radiates the focused ion beam onto a sample S, an image acquiring mechanism 17 which acquires a FIM image of the tip of the emitter, and a control unit 7 having a display unit and a storage unit 7b.

Abstract: An extreme ultraviolet light source apparatus provided with a magnetic field forming unit having sufficient capability of protection against ions radiated from plasma while using a relatively small magnetic source. The apparatus includes: a target nozzle for injecting a target material; a driver laser for applying a laser beam to the target material to generate plasma; a collector mirror for collecting extreme ultraviolet light radiated from the plasma; and a magnetic field forming unit including at least one magnetic source and at least one magnetic material having two leading end parts projecting from the at least one magnetic source to face each other with a plasma emission point in between, and forming a magnetic field between a trajectory of the target material and the collector mirror.

Abstract: An ion source is disclosed for use in fabrication of semiconductors. The ion source includes an electron emitter that includes a cathode mounted external to the ionization chamber for use in fabrication of semiconductors. In accordance with an important aspect of the invention, the electron emitter is employed without a corresponding anode or electron optics. As such, the distance between the cathode and the ionization chamber can be shortened to enable the ion source to be operated in an arc discharge mode or generate a plasma. Alternatively, the ion source can be operated in a dual mode with a single electron emitter by selectively varying the distance between the cathode and the ionization chamber.

Abstract: An atmospheric pressure ionization apparatus includes a chamber, an ion inlet structure, an electrode, a sample emitter, and a gas passage. The ion inlet structure includes a sampling orifice. The electrode includes an electrode bore. An ionization region is defined between the ion inlet structure and the electrode. The flared structure is coaxially disposed about the ion inlet structure, and extends along an outward direction that includes a radial component relative to the sampling axis. The sample emitter is oriented at an angle to the sampling axis for directing a sample stream toward the ionization region. The gas passage directs a stream of gas from a gas source to the chamber. The flared structure and the wall cooperatively form an outward-directed portion of the gas passage that extends annularly about the sampling axis and along the outward direction. The gas flows through the outward-directed portion, around the flared structure, and toward the ionization region and the electrode bore.

Abstract: A multi-sectional linear ionizing bar with at least four elements is disclosed. First, disclosed bars may include at least one ionization cell with at least one axis-defining linear ion emitter for establishing an ion cloud along the length thereof. Second, disclosed bars may include at least one reference electrode. Third, disclosed bars may include a manifold for receiving gas or air from a source and for delivering same past the linear emitter(s) such that substantially none of the gas/air flows into the ion cloud. Fourth, disclosed bars may include means for receiving the ionizing voltage and for delivering same to the linear emitter(s) to thereby establish the ion cloud. In this way, disclosed ionizing bars may transportions from the plasma region toward a charge neutralization target without inducing substantial vibration of the linear emitter and without substantial contaminants from the gas/air flow reaching the linear emitter.

Abstract: A system, method and apparatus for injecting reactive species and ions from an ambient plasma ionization source into an atmospheric pressure ion mobility spectrometer.

Abstract: Ion microscope methods and systems are disclosed. In general, the systems and methods involve relatively light isotopes, minority isotopes or both. In some embodiments, an isotope of Neon is used.

Abstract: A high pressure microplasma source operating in a normal glow discharge regime is used to produce a cold bright focused beam of Xe+ and/or Xe2+ ions having ion temperature of the order of 0.5-1 eV and a current density on the order of 0.1-1 A/cm2 or higher for focused ion beam applications.

Abstract: The process of the present application facilitates the production of electric energy by the deliberate extraction of electrons from atoms and molecules of a gas, vapor, liquid, particulate solid, or any other form of matter that can be passed along the surface or through the electron extraction unit. The extracted electrons are captured, collected and controlled or regulated for distribution as electric energy. It is an energy efficient process for the extraction and capture of electrons for the production of electric energy with positive atomic or molecular ions as byproducts. The product ions can then be confined in a coherent beam or restricted to a magnetic enclosure or by other confinement methods, expelled to the atmosphere, another environment or to ground, or modified into useful molecules. These results are accomplished by the forcible extraction and capture of electrons from the object particles by electrically charged particles in a strong electric field.

Abstract: The present invention is a device to restrict the sampling of analyte ions and neutral molecules from surfaces with mass spectrometry and thereby sample from a defined area or volume. In various embodiments of the present invention, a tube is used to sample ions formed with a defined spatial resolution from desorption ionization at or near atmospheric pressures. In an embodiment of the present invention, electrostatic fields are used to direct ions to either individual tubes or a plurality of tubes positioned in close proximity to the surface of the sample being analyzed. In an embodiment of the present invention, wide diameter sampling tubes can be used in combination with a vacuum inlet to draw ions and neutrals into the spectrometer for analysis. In an embodiment of the present invention, wide diameter sampling tubes in combination with electrostatic fields improve the efficiency of ion collection.

Abstract: A mass spectrometer includes an ion source, which includes a coating or surface formed of a metallic carbide, a metallic boride, a ceramic or DLC, or an ion-implanted transition metal.

Abstract: Disclosed are methods, apparatus, systems, processes and other inventions relating to: ion sources with controlled electro-pneumatic superposition, ion source synchronized to RF multipole, ion source with charge injection, optimized control in active feedback system, radiation supported charge-injection liquid spray, ion source with controlled liquid injection as well as various embodiments and combinations of each of the foregoing.

Abstract: A closed plasma channel (“CPC”) superconductor which, in a first embodiment, is comprised of an elongated, close-ended vacuum conduit comprising a cylindrical wall having a longitudinal axis and defining a transmission space for containing an ionized gas of vapor plasma (hereinafter “plasma components”), the plasma components being substantially separated into regionalized channels parallel to the longitudinal axis in response to a static magnetic field produced within the transmission space. Each channel is established along the entire length of the transmission space. At least one channel is established comprised primarily of free-electrons which provide a path of least resistance for the transmission of energy therethrough. Ionization is established and maintained by the photoelectric effect of a light source of suitable wavelength to produce the most conductive electrical transmission medium.

Abstract: An apparatus of an electron cyclotron resonance ion source may include: a magnet unit containing a magnet for generating magnetic fields; an ionizing chamber housing unit for generating ions through electron cyclotron resonance from a plasma; a microwave generating unit for injecting microwaves to the ionizing chamber housing unit to generate ions; and a beam integrating and guiding unit for treating the generated ions. The magnet unit may include: a bobbin for winding the magnet; a variable spacer for dividing the bobbin into a plurality of sections; and the magnet which is wound into the form of a wire or a tape in the plurality of sections formed by the variable spacer.

Abstract: The disclosure relates to ion beams systems, such as gas field ion microscopes, having multiple modes of operation, as well as related methods. In some embodiments, the disclosure provides a method of operating a gas field ion microscope system that includes a gas field ion source, where the gas field ion source includes a tip including a plurality of atoms.

Abstract: Provided are a large-current and highly stable gas field ionization ion source, and a high-resolution ion microscope with a large focal depth. The present invention relates to an ion microscope provided with a gas field ionization ion source, in which disposed are a refrigerator for cooling the gas field ionization ion source independent of the main body of the ion microscope, and a refrigerant circulation circuit cooling mechanism for circulating a refrigerant between the gas field ionization ion source and the refrigerator. Consequently it is possible to reduce the mechanical vibration of the refrigerator, which propagates to the gas field ionization ion source, and to achieve both the improvement of the brightness of the ion source and the improvement of ion beam focusing performance.

Abstract: An ion supply device includes an ion generator for generating ions for removing static electricity, a carrier gas supply unit for supplying to the ion generator a carrier gas for carrying the ions generated in the ion generator, and an ion supply nozzle for blowing the ions and the carrier gas from the ion generator through a blow-off opening toward an electricity removal target from which static electricity is to be removed. A slit is provided at the blow-off opening and has an increased width as the slit gets distant from the electricity removal target. The ion supply nozzle includes an internal flow path and a plurality of internal fins provided at a portion of the internal flow path near the blow-off opening so that the ions and the carrier gas blown from the slit is uniformly distributed along a lengthwise direction of the slit.

Abstract: An extreme ultraviolet light source apparatus in which only particles having a high transmittance for EUV light adhere to an EUV collector mirror even if fast ions emitted from plasma collide with a structural member in a vacuum chamber, and thereby, the reflectance thereof is not easily degraded. The apparatus includes: a vacuum chamber; a target supply unit for supplying a target to a predetermined position in the vacuum chamber; a driver laser for applying a laser beam to the target to generate the plasma; a collector mirror for collecting and outputting extreme ultraviolet light emitted from the plasma; a collector mirror holder for supporting the collector mirror; and a shielding member formed of a material having a high transmittance for the extreme ultraviolet light, for shielding the structural member such as the collector mirror holder from the ions generated from the plasma.

Abstract: A nozzle protection device capable of protecting a target nozzle from heat of plasma without disturbing formation of a stable flow of a target material in an LPP type EUV light source apparatus. This nozzle protection device includes a cooling unit which is formed with an opening for passing the target material therethrough, and which is formed with a flow path for circulating a cooling medium inside, and an actuator which changes a position or a shape of the cooling unit between a first state of evacuating the cooling unit from a trajectory of the target material and a second state of blocking heat radiation from the plasma to the nozzle by the cooling unit while securing a path of the target material in the cooling unit.

Abstract: An air cleaner includes a negative ion generation portion generating negative ions, a positive ion generation portion generating positive ions, a drive portion adjusting a distance between the ion generation portions, a wind velocity sensor detecting wind velocity at positions where the ion generation portions are installed, and a microcomputer controlling the drive portion based on a detection result of the wind velocity sensor and setting distance D between the ion generation portions to an optimal value. Therefore, since the distance between the ion generation portions is set to the optimal value, a large amount of ion generation can be obtained.

Abstract: Self-balancing, corona discharge for the stable production of electrically balanced and ultra-clean ionized gas streams is disclosed. This result is achieved by promoting the electronic conversion of free electrons into negative ions without adding oxygen or another electronegative gas to the gas stream. The invention may be used with electronegative and/or electropositive or noble gas streams and may include the use of a closed loop corona discharge control system.

Abstract: Suspended nanotubes are used to capture and ionize neutral chemical units, such as individual atoms, molecules, and condensates, with excellent efficiency and sensitivity. Applying a voltage to the nanotube(s) (with respect to a grounding surface) creates an attractive potential between a polarizable neutral chemical unit and the nanotube that varies as 1/r2, where r is the unit's distance from the nanotube. An atom approaching the nanotube with a sub-threshold angular momentum is captured by the potential and eventually spirals towards the nanotube. The atom ionizes as in comes into close proximity with a sidewall of the nanotube, creating an ion whose polarity matches the polarity of the electric potential of the nanotube. Repulsive forces eject the ion, which can be detected more easily than a neutral chemical unit. Suspended nanotubes can be used to detect small numbers of neutral chemical units (e.g., single atoms) for applications in sensing and interferometry.

Abstract: Droplets or plugs within multiphase microfluidic systems have rapidly gained interest as a way to manipulate samples and chemical reactions on the femtoliter to microliter scale. Chemical analysis of the plugs remains a challenge. It has been discovered that nanoliter plugs of sample separated by air or oil can be analyzed by electrospray ionization mass spectrometry when pumped directly into a fused silica nanospray emitter nozzle. Using leu-enkephalin in methanol and 1% acetic acid in water (50:50 v:v) as a model sample, we found carry-over between plugs was <0.1% and relative standard deviation of signal for a series of plugs was 3%. Detection limits were 1 nM. Sample analysis rates of 0.8 Hz were achieved by pumping 13 nL samples separated by 3 mm long air gaps in a 75 ?m inner diameter tube. Analysis rates were limited by the scan time of the ion trap mass spectrometer. The system provides a robust, rapid, and information-rich method for chemical analysis of sample in segmented flow systems.

Abstract: The present invention is a device to restrict the sampling of analyte ions and neutral molecules from surfaces with mass spectrometry and thereby sample from a defined area or volume. In various embodiments of the present invention, a tube is used to sample ions formed with a defined spatial resolution from desorption ionization at or near atmospheric pressures. In an embodiment of the present invention, electrostatic fields are used to direct ions to either individual tubes or a plurality of tubes positioned in close proximity to the surface of the sample being analyzed. In an embodiment of the present invention, wide diameter sampling tubes can be used in combination with a vacuum inlet to draw ions and neutrals into the spectrometer for analysis. In an embodiment of the present invention, wide diameter sampling tubes in combination with electrostatic fields improve the efficiency of ion collection.

Abstract: Ionization devices that have at least two modes of ionization, and that can switch between these two modes of operation, are described. Illustratively, the ionization devices can switch between a photoionization (PI) mode and a combined mode of electroionization (EI) and PI (EI/PI mode).

Abstract: The invention relates to an ion source means comprising at least one holding means for holding at least one sample to expose the sample to a mass spectrometer device, wherein the holding means comprises a structured sample support means for supporting the sample and/or a structured sample or sample comprising a structured surface, respectively.

Abstract: The present invention provides a method for extracting a charged particle beam from a charged particle source. A set of electrodes is provided at the output of the source. The potentials applied to the electrodes produce a low-emittance growth beam with substantially zero electric field at the output of the electrodes.

Abstract: The ion acceleration system or complex (T) for medical and/or other applications is composed in essence by an ion source (1), a pre-accelerator (3) and one or more linear accelerators or linacs (6, 8, 10, 13), at least one of which is mounted on a rotating mechanical gantry-like structure (17). The isocentrical gantry (17) is equipped with a beam delivery system, which can be either ‘active’ or ‘passive’, for medical and/or other applications. The ion source (1) and the pre-accelerator (3) can be either installed on the floor, which is connected with the gantry basement, or mounted, fully or partially, on the rotating mechanical structure (17). The output beam can vary in energy and intensity pulse-by-pulse by adjusting the radio-frequency field in the accelerating modules of the linac(s) and the beam parameters at the input of the linear accelerators.

Abstract: A device is described, which is sensitive to electric fields, but is insensitive to stray electrons/ions and unlike a bare, exposed conductor, it measures capacitively coupled current while rejecting currents due to charged particle collected or emitted. A charged particle beam establishes an electric field inside the beam pipe. A grounded metallic box with an aperture is placed in a drift region near the beam tube radius. The produced electric field that crosses the aperture generates a fringe field that terminates in the back surface of the front of the box and induces an image charge. An electrode is placed inside the grounded box and near the aperture, where the fringe fields terminate, in order to couple with the beam. The electrode is negatively biased to suppress collection of electrons and is protected behind the front of the box, so the beam halo cannot directly hit the electrode and produce electrons.

Abstract: A charged particle gun includes: a charged particle source; a first extracting electrode arranged in such a manner that a distance between the charged particle source and the first extracting electrode is fixed; a second extracting electrode located on the side opposite to the charged particle source with respect to the first extracting electrode, the electrode being arranged in such a manner that a distance between the first extracting electrode and the second extracting electrode is adjustable; and an earth electrode located on the side opposite to the first extracting electrode with respect to the second extracting electrode, the electrode being arranged in such a manner that a distance between the second extracting electrode and the earth electrode is fixed; wherein the first extracting electrode is equal in potential to the second extracting electrode.

Abstract: An EUV light source device properly compensates the wave front of laser beam which is changed by heat. A wave front compensator and a sensor are provided in an amplification system which amplifies laser beam. The sensor detects and outputs changes in the angle (direction) of laser beam and the curvature of the wave front thereof. A wave front compensation controller outputs a signal to the wave front compensator based on the measurement results from the sensor. The wave front compensator corrects the wave front of the laser beam to a predetermined wave front according to an instruction from the wave front compensation controller.

Abstract: The present invention discloses a system and method for generating a beam of fast ions. The system comprising: a target substrate having a patterned surface, a pattern comprising nanoscale pattern features oriented substantially uniformly along a common axis; and; a beam unit adapted for receiving a high power coherent electromagnetic radiation beam and focusing it onto said patterned surface of the target substrate to cause interaction between said radiation beam and said substrate enabling creation of fast ions.

Abstract: Monatomic metal anions are generated in the gas phase by collision-induced dissociation of the anions [26] of a dicarboxylic acid salt of the metal. This method is applicable to a number of metals, including sodium, potassium, cesium, and silver. The metal anions produced in this way can subsequently be stored in an ion trap [88] or transmitted as a focused beam [52]. The metal anions of this invention undergo collisional cooling and have low kinetic energy, which distinguishes them from ions produced by other high energy processes (with kinetic energy in excess of 1 keV). Metal anions so produced can be used to pattern nanoscale features on surfaces [56], used as electron transfer agents or reducing agents in ion-molecule reactions, or used for surface [122] modification of biomaterials [124].

Abstract: An ion generation device includes an ion generator that generates ions, an ion detector that detects generated ions, a blower that blows the generated ions to outside through a draft air duct, and a control unit that performs drive control of the ion generator and the blower. When the control unit detects absence of generation of ions at a time of starting operation or the like, the control unit stops driving of the ion generator for a short time while keeping the blower driving, and purges staying ions, after which, the control unit carries out ion detection by the ion detector, and determines presence or absence of ion generation. When the control unit determines that ion generation is absent, the control unit continuously performs determination of ion generation a plurality of times, and if ion generation is absent in all the determinations, finally determines generation of ions as absent.

Abstract: This invention describes an apparatus and method with a combined primary electrospray and secondary electrospray ionization source used to enhance ionization efficiency. The solid phase as well as liquid phase sampling, ionization, and detection is described.

Abstract: A closed plasma channel (“CPC”) superconductor which, in a first embodiment, is comprised of an elongated, close-ended vacuum conduit comprising a cylindrical wall having a longitudinal axis and defining a transmission space for containing an ionized gas of vapor plasma (hereinafter “plasma components”), the plasma components being substantially separated into regionalized channels parallel to the longitudinal axis in response to a static magnetic field produced within the transmission space. Each channel is established along the entire length of the transmission space. At least one channel is established comprised primarily of free-electrons which provide a path of least resistance for the transmission of energy therethrough. Ionization is established and maintained by the photoelectric effect of a light source of suitable wavelength to produce the most conductive electrical transmission medium.

Abstract: Charged spray droplets are guided in a pseudopotential distribution generated by audio frequency voltages at electrodes of a guiding device, focusing the spray droplets toward the axis. An axial electric field profile and an axial flow profile of a drying gas in the guiding device allow the drift of different-sized droplets to be controlled in the longitudinal direction of the guiding device, so that the droplets are roughly equal in size when they leave the guiding device and finally dry up shortly after leaving. As a result, the ions are formed in a relatively small spatial region. Electrostatic potentials guide the analyte ions from this small spatial region to the entrance aperture of the inlet capillary; during this process, very light ions, especially protons and water-proton complexes, can be filtered out by a mobility filter.

Abstract: A plasma radiation source includes a vessel configured to catch a source material transmitted along a trajectory, and a decelerator configured to reduce a speed of the source material in a section of the trajectory downstream of a plasma initiation site.

Abstract: A patterned beam of radiation is projected onto a substrate. A reflective optical element is used to help form the radiation beam from radiation emitted from a plasma region of a plasma source. In the plasma source, a plasma current is generated in the plasma region. To reduce damage to the reflective optical element, a magnetic field is applied in the plasma region with at least a component directed along a direction of the plasma current. This axial magnetic field helps limit the collapse of the Z-pinch region of the plasma. By limiting the collapse, the number of fast ions emitted may be reduced.

Abstract: A combined plenum divider/hopper is provided for a grain drying tower. The divider/hopper is positioned in the drying tower proximate the heater for the drying tower and is operable to adjust the ratio of the length of the heating portion of the plenum to the length of the cooling portion of the plenum.

Abstract: In an extreme ultra violet light source apparatus of a laser produced plasma type, charged particles such as ions emitted from plasma are promptly ejected to the outside of a chamber. The apparatus includes a chamber, a target supply unit for supplying a target material into the chamber, a collector mirror for collecting extreme ultra violet light radiated from plasma generated by irradiating the target material with a laser beam to output the extreme ultra violet light, an electromagnet arranged outside of the chamber, and a charged particle collection mechanism provided on at least one of two surfaces of the chamber to which lines of magnetic force generated by the electromagnet extend.

Abstract: An ionization device comprises: a plasma source configured to generate a plasma. The plasma comprises light, plasma ions and plasma electrons. The plasma source comprises an aperture disposed such that at least part of the light passes through the aperture and is incident on a gas sample. The ionization device further comprises an ionization region; and a plasma deflection device comprising a plurality of electrodes configured to establish an electric field, wherein the electric field substantially prevents the plasma ions from entering the ionization region.

Abstract: The present invention relates to a debris mitigation device for use with a radiation source (2) generating optical radiation, in particular extreme ultraviolet radiation (EUV) or soft x-rays, and emitting undesired substances and/or particles which can deposit on optical surfaces in a radiation path of said radiation source (2), and to a corresponding drive assembly. The debris mitigation device comprises at least one rotating foil trap (5) and the drive assembly. The drive assembly comprises a driving motor (14) and a driving axis (10), to which the rotating foil trap (5) is fixed. The driving motor (14) and bearings (13) supporting the driving axis (10) are enclosed in a casing (20) having an aperture for the driving axis (10) and at least one outlet opening (21) for a sealing gas. The outlet opening (21) is connectable to a pump for pumping out the sealing gas.

Abstract: An electron beam emitter includes an electron generator for generating electrons. The electron generator can have a housing containing at least one electron source for generating the electrons. The at least one electron source has a width. The electron generator housing can have an electron permeable region spaced from the at least one electron source for allowing extraction of the electrons from the electron generator housing. The electron permeable region can include a series of narrow elongate slots and ribs formed in the electron generator housing and extending laterally beyond the width of the at least one electron source. The electron permeable region can be configured and positioned relative to the at least one electron source for laterally spreading the electrons that are generated by the at least one electron source.

Abstract: An atmospheric pressure ionization apparatus includes a chamber, an ion inlet structure, an electrode, a sample emitter, and a gas passage. The ion inlet structure includes a sampling orifice. The electrode includes an electrode bore. An ionization region is defined between the ion inlet structure and the electrode. The flared structure is coaxially disposed about the ion inlet structure, and extends along an outward direction that includes a radial component relative to the sampling axis. The sample emitter is oriented at an angle to the sampling axis for directing a sample stream toward the ionization region. The gas passage directs a stream of gas from a gas source to the chamber. The flared structure and the wall cooperatively form an outward-directed portion of the gas passage that extends annularly about the sampling axis and along the outward direction. The gas flows through the outward-directed portion, around the flared structure, and toward the ionization region and the electrode bore.

Abstract: A system and methods are described for generating reagent ions and product ions for use in a mass spectrometry system. Applications for the system and method are also disclosed for detecting volatile organic compounds in trace concentrations. A microwave or high-frequency RF energy source ionizes particles of a reagent vapor to form reagent ions. The reagent ions enter a chamber, such as a drift chamber, to interact with a fluid sample. An electric field directs the reagent ions and facilitates an interaction with the fluid sample to form product ions. The reagent ions and product ions then exit the chamber under the influence of an electric field for detection by a mass spectrometer module. The system includes various control modules for setting values of system parameters and analysis modules for detection of mass and peak intensity values for ion species during spectrometry and faults within the system.

Abstract: It is expected to provide an ion generating apparatus and an ion presence determination method that can prevent the lower accuracy of the ion presence determination caused by the humidity effect. The ion generators are switched ON at the different timing, the electrical potential of the collecting electrode is measured to determine that the ion is present (or not present) when the voltage difference is larger (or smaller) than the threshold. A humidity detecting unit is arranged in a duct. The set threshold for the determination is based on the humidity of the humidity detecting unit, and the ion presence determination is not performed when the humidity is equal to or more than a predetermined humidity. When the determination representing no ion is obtained predetermined times, the warning is output for the users with a LED of a display, a buzzer of a controller or the like.

Abstract: A charged particle beam device is described. The device includes an emitter unit including an emitter tip; a voltage supply unit adapted for providing a stable voltage to generate a stable extraction field at the emitter tip; a pulsed voltage supply member adapted for providing a pulsed voltage to generate a pulsed extraction field on top of the stable extraction field; a measuring unit for measuring an emitter characteristic; and a control unit adapted for receiving a signal from the measuring unit and for control of the pulsed voltage supply member.

Abstract: An electrically conductive heat-blocking plate 11 with an opening 12 for allowing thermions to pass through is provided between a filament 3, whose temperature can be as high as 2000° to 3000° C., and an ionization chamber 2. The heat-blocking plate 11 is thermally connected via an aluminum block 10 to a heater for maintaining the ionization chamber 2 within a range temperature from 200° to 300° C., and also electrically set at a ground potential, which is approximately equal to the potential of the ionization chamber 2. The heat-blocking plate 11 blocks the radiation heat that the filament 3 emits when energized. Thus, the wall of the ionization chamber 2 is prevented from being locally heated to an abnormally high temperature. As a result, the inner space of the ionization chamber 2 is maintained at an approximately uniform temperature, and the noise due to the decomposition of a metallic material by abnormal heating is prevented.