Hitachi, Ltd.

Makoto Yasuda

Seiichi Murayama

Tsune Miyashita

Yukio Okamoto

Masataka Koga

Yoji Arai

Masaru Ito

Konosuke Oishi

Manabu Yamamoto

Kazunori Kinoshita

Toshihiko Sekizawa

Kenichi Kawasumi

Satoshi Shimura

Kunifusa Kayama

Fuzio Yamada

Hiroyuki Matsumura

Takahashi Iino

Makoto Watanabe

A mass spectrometer using a plasma ion source for analyzing an ultra-trace element includes a plasma generation system for generating a plasma including the composition of a sample, an ion beam formation system for extracting ions in the form of a beam from the plasma generating the ions, a mass spectrometry system for performing mass spectrometry of the ion beamn, and an ion detection system for detecting the ions subjected to the mass spectrometry, in which a lens system made up of a cylindrical first electrode, a cylindrical second electrode with a photon stopper disposed on the central axis thereof, and a cylindrical third electrode is further provided between the ion beam formation system and the mass spectrometry system. By the provision of the lens system, the ions generated in the plasma are transported more efficiently to the side of the mass spectrometry system and by the provision of the photon stopper in the above described position, it is achieved, with a simpler structure, to prevent photons from entering the ion detection system.

Mass spectrometer using plasma ion source

A microwave induced plasma source includes a coaxial waveguide made up of a cylindrical outer conductor and an inner conductor which has the form of a helical coil, a discharge tube inserted into the helical coil in the axial direction thereof, and having an inner tube for introducing a sample and an outer tube for introducing a plasma gas so that a double tube structure is formed, a discharge-tube cooling device for causing a cooling gas to flow along the outer periphery of the discharge tube in directions parallel to the axis thereof, and a microwave power source for supplying microwave power to the coaxial waveguide. When the microwave induced plasma source is used as the light source of a spectrometer or the ion source of a mass spectrometer, a trace element can be readily determined qualitatively or quantitatively.

Microwave induced plasma source

A plasma trace element spectrometer comprises a microwave generator for generating microwave power, a microwave feeder for guiding and transforming the generated microwave power into microwave power of TE.sub.01 mode and supplying the microwave power of TE.sub.01 mode, a plasma producer having, at one end, an introduction port for a carrier gas and a sample and at the other end an opening and being cooperative with the supplied microwave power of TE.sub.01 mode to produce plasma of the carrier gas and sample introduced through the introduction port, and a spectrometer for analyzing constituent elements of the sample by measuring the produced plasma by way of the opening.

Trace element spectrometry with plasma source

A PWM (pulse width modulation) inverter generating an a.c. output having a variable voltage and a variable frequency supplies a.c. power to a linear induction motor. An electric car supported by wheels is driven by a driving torque produced by the linear induction motor. While the electric car is running, the motor torque varies due to various factors among which a variation of the air gap length is representative. The power factor cos .phi. of the PWM inverter is detected to calculate the motor torque, and the output voltage of the PWM inverter is regulated or mechanical brakes are controlled so as to compensate the torque variation. Thus, the variation of the air gap length, which is representative of the factors giving rise to torque variations and which has been difficult to be detected, can be reliably detected to permit torque control according to the torque variation of the linear induction motor.

Apparatus and method for controlling electric car

Disclosed is an apparatus for stabilizing the light output of a high pressure discharge lamp comprising a coil generating a magnetic field acting upon the arc of the high pressure discharge lamp, an arc position detector detecting deviation of the position of the arc, and a magnetic field control circuit controlling the coil in response to the deviation detection output signal of the the arc position detector thereby setting right the position of the arc of the high pressure discharge lamp.

Apparatus for automatically correcting arc position of high pressure

A high-pressure discharge lamp operating circuit performs a low-frequency AC operating at an early stage of operating and thereafter performs a high-frequency AC operation or DC operation during the steady-state of lamp operation. This circuit comprises a circuit for effecting a transition from the low-frequency AC operation to the high-frequency AC operation or DC operation either at the time which is a predetermined time period after the ignition of discharge before the high-pressure discharge lamp reaches the steady-state of operation, or after having detected at least one of predetermined lamp characteristics, thereby providing a stabilized light output.

High-pressure discharge lamp operating circuit

An instrument for spectroscopy according to this invention uses a metal halide lamp, in which at least mercury and dysprosium halide are enclosed, as the light source for the purpose of effecting measurements for a wavelength region extending from the ultraviolet to the visible light with a single light source. This metal halide lamp has a spectre, which is effective in a wavelength region extending from about 200 nm to about 700 nm.

Instrument for spectroscopy having metal halide lamp as light source

A discharge lamp comprising an inner arc tube and an outer tube enclosing the inner tube. The outer tube is filled with neon at a pressure of 0.1 atm or more, or a gas mixture of neon in 80 pressure percent or more and breakdown suppressing gas.

Discharge lamp with neon gas in outer tube

A high intensity ultraviolet light-source comprises an arc tube having a pair of electrodes, filled with certain amounts of mercury, tantalum halide and rare gas, and provided with a tube loading of at least 13 Watt/cm.sup.2.

High intensity ultraviolet light source

A high pressure discharge lamp in which discharge between a pair of main electrodes in an arc tube of the discharge lamp is sustained by a D.C. or high frequency current. The circuit comprises discharge mode controller for controlling the discharge such that mainly a low-frequency discharge is produced between the main electrodes at least within a predetermined time from initiation of the discharge within the arc tube, and subsequently transferred to the D.C. or high-frequency discharge.

A liquid chromatography apparatus comprises a detector part having as a light source a metal halide lamp filled with tantalum halide, mercury and rare gas.

Liquid chromatography apparatus

Disclosed is a system for controlling the temperature of an atomizer for an element analyzer, said system comprising a birefringent prism arranged on the optical axis of radiant light emitted out of the atomizer, and a light sensor for detecting the radiant light which passes through said birefringent prism.

Temperature control system for an element analyzer

A high frequency discharge lamp for a spectral-line source includes a discharge envelope in which a substance contributive to the emission of desired spectral lines is contained and in which one electrode is included, the discharge envelope being made of a material, such as quartz, which is electrically insulating and capable of transmitting the spectral lines. A cylindrical metallic container surrounds the discharge envelope and has at a part thereof an opening for taking out the spectral lines. There is further provided means for applying a high-frequency voltage between the electrode and the metallic container.

Growing community of inventors

Kodaira, Japan

Makoto Yasuda