411 results about "Drift tube" patented technology

A method is described for producing tubular substrates having parallel spaced concentric rings of electrical conductors that can be used as the drift tube of an Ion Mobility Spectrometer (IMS). The invention comprises providing electrodes on the inside of a tube that are electrically connected to the outside of the tube through conductors that extend between adjacent plies of substrate that are combined to form the tube. Tubular substrates are formed from flexible polymeric printed wiring board materials, ceramic materials and material compositions of glass and ceramic, commonly known as Low Temperature Co-Fired Ceramic (LTCC). The adjacent plies are sealed together around the electrode.

The invention relates to the feeding of analyte ions, generated at atmospheric pressure, efficiently into the mass spectrometer. The invention provides a lengthy ion mobility drift tube with a focusing electric field inside to guide the ions from an ionization cloud generated at atmospheric pressure towards the entrance opening of the mass spectrometer, and to dry droplets which might occur in the ionization cloud by a hot drying gas flowing through the ion mobility drift tube towards the ionization cloud.

One embodiment disclosed relates to a scanning electron beam apparatus including an objective lens, scan deflectors, de-scan deflectors, an energy-filter drift tube, and a segmented detector. The objective lens may be an immersion lens configured with a high extraction field so as to preserve azimuthal angle discrimination of the electrons scattered from the specimen surface. The de-scan deflectors may be used to compensate for the scanning of the incident electron beam. The energy-filter drift tube is configured to align the scattered electrons according to polar angles of trajectory from the specimen surface.

Particular aspects provide novel methods for analysis of ion populations, the methods comprising filtering and selecting an ion population using a low-field dual-gate ion mobility spectrometer comprising a drift tube, the spectrometer operating at a pressure of at least 100 Torr, to provide mobility-selected ions. Certain aspects comprise: (i) subsequently accumulating the low-field selected ions in an ion trap (e.g., an MS ion trap) and mass spectrometry analysis; (ii) introducing the low-field selected ions into a high-field ion mobility spectrometer for separating thereby (optionally followed by mass spectrometry); and (iii) introducing the low-field selected ions into an ion trap mass spectrometer, and subsequently into a second low-field ion mobility spectrometer (e.g., a non-dual gate spectrometer operating at less than about 100 Torr). Additional aspects provide novel apparatus and combination thereof for performing the disclosed methods.

The invention discloses a near-field plume mass-spectroscopic diagnostic E*B probe based on the Faraday cup and belongs to the technical field of plasma mass-spectroscopic diagnosis. The probe mainly applied to measuring near-field plumes of an ion thruster and of a Hall thruster comprises a central frame, ferrite permanent magnets, a flat electrode plate, an electrode plate holder, a collimator tube, a drift tube, a Faraday cup, six carbon steel shells and an anti-sputtering heat-insulating layer. According to the connectional relation, the central frame is used as a core part, the ferrite permanent magnets are distributed on upper and lower surfaces of the central frame, the electrode plate is fixed in the central frame, and an orthogonal electromagnetic field area is formed. The six carbon steel shells are used for packaging, and the front ends of the shells are coated with an anti-sputtering heat-insulating layer. The collimator tube of stainless steel and the drift tube are fitly fixed to the centers of two ends of the central frame through shaft holes. Ions different in valence are screened by adjusting voltage among the electrode plates, univalent and bivalent ion currents are acquired with the Faraday cup of aluminum, and the ratio of near-field plum bivalent ions is acquired by analytical computing.

There is provided of an on mobility spectrometer for separating ions according to their on mobility comprising, in various aspects: a drift tube having therein a drift space and in the drift space at least two on separation paths of different lengths: a straight drift tube having therein a helical ion separation path; a helical on separation path surrounding an axially extending inner electrode assembly; and a drift tube for separating ions according to their ion mobility wherein a rotating arcuate electric field is applied in operation to separate ions having an ion mobility such that their rotational velocity in the drift tube is matched to the rotational velocity of the rotating arcuate electric field. Various methods for separating ions according to their on mobility are also provided.

A method and apparatus enabling increased sensitivity in ion mobility spectrometry / mass spectrometry instruments which substantially reduces or eliminates the loss of ions in ion mobility spectrometer drift tubes utilizing a device for transmitting ions from an ion source which allows the transmission of ions without significant delay to an hourglass electrodynamic ion funnel at the entrance to the drift tube and / or an internal ion funnel at the exit of the drift tube. An hourglass electrodynamic funnel is formed of at least an entry element, a center element, and an exit element, wherein the aperture of the center element is smaller than the aperture of the entry element and the aperture of the exit elements. Ions generated in a relatively high pressure region by an ion source at the exterior of the hourglass electrodynamic funnel are transmitted to a relatively low pressure region at the entrance of the hourglass funnel through a conductance limiting orifice. Alternating and direct electrical potentials are applied to the elements of the hourglass electrodynamic funnel thereby drawing ions into and through the hourglass electrodynamic funnel thereby introducing relatively large quantities of ions into the drift tube while maintaining the gas pressure and composition at the interior of the drift tube as distinct from those at the entrance of the electrodynamic funnel and allowing a positive gas pressure to be maintained within the drift tube, if desired. An internal ion funnel is provided within the drift tube and is positioned at the exit of said drift tube. The advantage of the internal ion funnel is that ions that are dispersed away from the exit aperture within the drift tube, such as those that are typically lost in conventional drift tubes to any subsequent analysis or measurement, are instead directed through the exit of the drift tube, vastly increasing the amount of ions exiting the drift tube.

A charged particle beam apparatus in which an electrostatic lens is used as a main focusing element to obtain a subminiature high-sensitivity high-resolution SEM, a drift tube for an electron beam is located inside a column between an electron source and a sample, and a detector for secondary electrons is located inside the drift tube. This solves the problem associated with the provision of a secondary electron detector, which heretofore has been a bottleneck in making a subminiature high-resolution SEM column.

Particular aspects provide novel methods for analysis of ion populations, the methods comprising filtering and selecting an ion population using a low-field dual-gate ion mobility spectrometer comprising a drift tube, the spectrometer operating at a pressure of at least 100 Torr, to provide mobility-selected ions. Certain aspects comprise: (i) subsequently accumulating the low-field selected ions in an ion trap (e.g., an MS ion trap) and mass spectrometry analysis; (ii) introducing the low-field selected ions into a high-field ion mobility spectrometer for separating thereby (optionally followed by mass spectrometry); and (iii) introducing the low-field selected ions into an ion trap mass spectrometer, and subsequently into a second low-field ion mobility spectrometer (e.g., a non-dual gate spectrometer operating at less than about 100 Torr). Additional aspects provide novel apparatus and combination thereof for performing the disclosed methods.

A time-of-flight ion sensor for monitoring ion species in a plasma includes a housing. A drift tube is positioned in the housing. An extractor electrode is positioned in the housing at a first end of the drift tube so as to attract ions from the plasma. A plurality of electrodes is positioned at a first end of the drift tube proximate to the extractor electrode. The plurality of electrodes is biased so as to cause at least a portion of the attracted ions to enter the drift tube and to drift towards a second end of the drift tube. An ion detector is positioned proximate to the second end of the drift tube. The ion detector detects arrival times associated with the at least the portion of the attracted ions.

A neutron tube or generator is based on a RF driven plasma ion source having a quartz or other chamber surrounded by an external RF antenna. A deuterium or mixed deuterium / tritium (or even just a tritium) plasma is generated in the chamber and D or D / T (or T) ions are extracted from the plasma. A neutron generating target is positioned so that the ion beam is incident thereon and loads the target. Incident ions cause D-D or D-T (or T-T) reactions which generate neutrons. Various embodiments differ primarily in size of the chamber and position and shape of the neutron generating target. Some neutron generators are small enough for implantation in the body. The target may be at the end of a catheter-like drift tube. The target may have a tapered or conical surface to increase target surface area.

The invention discloses an X wave band over-mode relativistic klystron amplifier, which comprises an annular cathode, a resonant reflector, an input cavity, a first section of drift tube, a wave absorbing material, a buncher cavity, a second section of drift tube, an output cavity and a magnetic field coil, wherein the annular cathode is arranged at the most significant end of the structure and emits annular relativistic electron beams outwards under the action of high voltage pulse, the resonant reflector, the input cavity, the first section of drift tube, the wave absorbing material, the buncher cavity, the second section of drift tube and the output cavity are sequentially arranged at rear of the annular cathode, the magnetic field coil is installed at the periphery of the whole structure, the working mode of the resonant reflector, the input cavity, the buncher cavity and the output cavity is a TM02 mode, and the first section of drift tube and the second section of drift tube can transmit a TM01 mode. The X wave band over-mode relativistic klystron amplifier can produce high power X wave band microwave.

A time-of-flight ion sensor for monitoring ion species in a plasma includes a housing. A drift tube is positioned in the housing. An extractor electrode is positioned in the housing at a first end of the drift tube so as to attract ions from the plasma. A plurality of electrodes is positioned at a first end of the drift tube proximate to the extractor electrode. The plurality of electrodes is biased so as to cause at least a portion of the attracted ions to enter the drift tube and to drift towards a second end of the drift tube. An ion detector is positioned proximate to the second end of the drift tube. The ion detector detects arrival times associated with the at least the portion of the attracted ions.