Abstract: Apparatus (10) for measuring absolute specular reflectance of a surface of a sample (22) includes a sample holder (12), a light source (18) for transmitting an incident light beam (16) onto a surface of the sample (22) and a detector (26 ) for detecting a specularly reflected component of the incident light. The light source (18), sample holder (12) and detector (26) are mounted and operatively associate (14, 24, 28) to be relatively moveable to vary the angle of incidence of light (16) onto sample (22) and to correspondingly automatically vary the relative position of the detector (26) such that the angle of reflection equals the angle of incidence. In the absence of the sample (22) or upon removal of the sample holder (12), light (16) impinges directly onto detector (26) to directly allow measurement of the absolute intensity of the light beam (16) as a reference measurement. This avoids the need to use intervening optical components such as mirrors which may degrade over time.

Abstract: An apparatus for use in atmospheric pressure ionization includes a sample receiving chamber, a sample droplet source communicating with the sample receiving chamber, an outlet conduit, and a boundary. The outlet conduit defines a sampling orifice that communicates with the sample receiving chamber. The boundary is interposed between the sample receiving chamber and the sampling orifice and comprises an opening. The opening defines a first passage through which a drying gas is flowable into the sample receiving chamber in an elongated flow profile, and a second passage through which sample material is flowable from the sample receiving chamber toward the sampling orifice. The first passage is positioned in non-coaxial relation to the second passage. The first passage is configured to introduce the elongated flow profile of the drying gas into a pathway of droplets of the sample material flowing toward the second passage.

Abstract: A gas-selective permeable membrane (1) utilisable in a leak detector for a gas, more particularly helium, comprising a sheet-like body (11) on which at least one reduced thickness area (15) is defined by removing a material from the sheet-like body. This at least one reduced thickness area (15) being permeable to at least one gas and formed so as that it is partly surrounded by a thicker and substantially gas-impermeable area (16) ensuring the structural strength of the membrane.

Abstract: A process for manufacturing stators of vacuum pumps, and stators obtained thereby, wherein a plurality of stator discs or rings are formed, preferably by pressing, and then stator discs or rings are coaxially stacked and mutually rotated so as to form a stator surface having defined thereon at least one groove extending in substantially axial direction with respect to a body of the stator.

Abstract: A plasma source mass spectrometer (20) having an ion beam extraction electrode (45) associated with a skimmer cone (40) to restrict the pumping of gas from a region (60) immediately behind the skimmer cone orifice (42) to provide a higher pressure (e.g. 1–10?2 Torr) in the region (60) compared to the pressure downstream of the electrode (45) (e.g. 10?3–10?4 Torr). This provides a collisional gas volume (60) for plasma (28) for attenuating polyatomic and multicharged interfering ions prior to extraction of an ion beam (49). In one embodiment a substance (e.g. hydrogen) can be supplied into the region (60) to assist attenuation of polyatomic and multicharged interfering ions by reactive or collisional interactions.

Abstract: In some embodiments, a nuclear magnetic resonance (NMR) sample container having an elongated transverse cross-section is held in a predetermined azimuthal orientation in an NMR probe by keying-in a sample container holder into a matching azimuthal-alignment adapter. The azimuthal-alignment adapter may be a lead-in adapter having an azimuthally-sloping upper guiding surface of a cylindrical shell part, with the sloping guiding surface leading into a longitudinal channel defined through the shell wall. A transversely-protruding pin of the sample container holder slides down the guiding surface and into the longitudinal channel to lock the sample in the desired azimuthal orientation.

Abstract: A controller for apparatus assuming a sequence of precisely synchronized states in accordance with a lengthy event stream is realized in an architecture comprising a register layer comprising a plurality of latched registers for receiving event descriptors and parameters from a bus and a computational/logical layer for operations on/among certain of said parameters for presentation to external operational devices. An RF controller controlling frequency, pulse width, amplitude with precise timing for magnetic resonance applications is one example and a magnetic gradient controller controlling vector magnitude and orientation is another.

Abstract: A micro-electro-mechanical vibrating pumping stage comprises a silicon substrate (15) on which there are formed a single-layer or multilayer oscillating assembly (27; 127; 227; 327) with a vibrating membrane and a device controlling the membrane in order to provide its oscillation with respect to the substrate. A molecular vacuum pump incorporates this vibrating pumping stage.

Abstract: A sample probe and apparatus are provided for magnetic resonance experiments. The probe includes a coil simultaneously tunable to at least two different frequencies. The coil includes a section having a scroll configuration and defines a core into which a sample can be inserted. A multi-resonant circuit transmits RF energy to the coil at two or more different frequencies for exciting nuclei of the sample. The apparatus includes a coil having a scroll configuration. RF transmission circuitry transmits RF energy to the coil at two or more different frequencies. RF receiving circuitry receives an RF signal responsive to excitation. A coil is magnetically coupled with a sample at an RF frequency.

Abstract: Nuclear magnetic resonance (NMR) systems and methods employing squashed (transversely-elongated) sample vessels (sample tubes or flow cells) for holding liquid NMR samples, and matching squashed saddle-shaped RF coils allow reducing sample and/or coil losses and increasing the RF circuit quality factors (Q). In a present implementation, the RF coils and sample vessels have rectangular cross-sections. Rounded (e.g. ellipsoidal) or other squashed cross-sections may also be used. The coil corresponding to the highest sample losses is positioned such that the magnetic field generated by the coil is along the major axis of the sample vessel. Squashed sample vessels may also be used with conventional circular coils, particularly for low-temperature measurements where sample losses dominate.

Abstract: A split capacitance-tuning band of a nuclear magnetic resonance (NMR) distributed-capacitance radio-frequency (RF) coil includes a fixed band and a longitudinally-movable (sliding) band, both disposed to overlap a central coil structure. The fixed band is situated along the boundary of the RF coil window. The movable band can move between a proximal position abutting the fixed band and various distal positions. The fixed band provides an RF current path close to the RF coil window, while the movable band allows tuning the coil capacitance and resonance frequency by varying the area of overlap between the movable band and the central coil structure. A longitudinal coupling member is attached to the movable band and to an actuator piston disposed under a probe lower insulator. A chip capacitor is connected between the coupling member and the actuator piston, to provide RF insulation for the movable capacitance band.

Abstract: A leak detector comprises a high vacuum envelope connected with a vacuum pump to bring the vacuum envelope to a pressure sensibly lower than ambient pressure. At least a portion of the envelope is separated from an external environment through a quartz membrane associated with an electrical resistor, which heats the membrane to a sufficient temperature in order to make it permeable to a corresponding test gas (in particular, helium). In operation, an electronic control unit detects variations in the current absorbed by the vacuum pump and consequently signals the test gas diffusion into the chamber and hence the existence of a leak. A sampling line with a sampling pump disposed therein is connected to a probe for the intake of gas directed to expose to the membrane. The gas is discharged to the outside through a discharge line. A system for switching between the gas intake and exhaust is provided, in order to quickly eliminates any test gas trace from said detector.

Abstract: A pressure sensor is a micro-electro-mechanical vibrating device, with a silicon substrate (15; 15?) onto which a single-layer or multilayer vibrating assembly (121; 221; 321) is formed. It comprises an electrode (21; 21?), which makes the assembly to oscillate relative to the substrate at the resonance frequency or at another known frequency, and a detector for detecting the actual frequency and/or amplitude of said oscillation. The actual frequency and/or amplitude are affected by the conditions, in particular the pressure, of the external environment and the variations of the frequency and amplitude with respect to the values set by the electrode is used to measure pressure variations in the surrounding environment.

Abstract: The disclosure describes a variable capacitor device, which is formed by a linear motor and a variable capacitor having at least one stator electrode and a movable electrode. A piezoelectric transducer of the linear motor is frictionally coupled to the movable electrode. Application of electrical signals to the piezoelectric transducer of the linear motor produces a motion of the surface of the piezoelectric transducer. The frictional coupling between the piezoelectric transducer surface and the movable electrode transmits a fraction of piezoelectric transducer motion to the movable piston electrode thereby changing the capacity of the variable capacitor. The amount and sign of the capacitance change is selectable by the operator through control of the electrical signals applied to the piezoelectric transducer.

Abstract: A controller for apparatus assuming a sequence of precisely synchronized states in accordance with a lengthy event stream is realized in an architecture comprising a register layer comprising a plurality of latched registers for receiving event descriptors and parameters from a bus and a computational/logical layer for operations on/among certain of said parameters for presentation to external operational devices. An RF controller controlling frequency, pulse width, amplitude with precise timing for magnetic resonance applications is one example and a magnetic gradient controller controlling vector magnitude and orientation is another.

Abstract: An ionisation vacuum gauge for measuring the residual pressure of a gaseous material remaining in a container (10), more particularly after operation of a vacuum pump comprises an electron-emitting cathode (31) made by exploiting the nanotube technology, a grid (13; 33; 133; 133?) for accelerating the electrons emitted by the cathode, and a plate (15; 35) collecting the ions and/or the ionised positive molecules of the gas. Measuring the plate current by a galvanometer allows for determining the value of the residual pressure inside the container.

Abstract: In a method for optimizing an ion detector a control voltage, such as in a mass spectrometry system, an array of mass scan data is acquired. Based on the size of the largest peak in the array or part of the array, a determination is made as to whether the current detector gain should be changed to a new detector gain. If the current detector gain should be changed, the control voltage for the subsequent mass scan is adjusted to a new control voltage corresponding to the new detector gain. The data are scaled based on the current detector gain. In another method, a gain versus control voltage curve is generated for calibration. These methods may be implemented by hardware, software, analog or digital circuitry, and/or computer-readable or signal-bearing media.

Abstract: A mass spectrometer and method of mass spectrometry in which polyatomic and doubly charged ion interferences are attenuated by establishing an electron population through which a beam of particles containing elemental sample ions and the interfering ions is passed such that the interfering ions preferentially undergo ion-electron recombination and thus dissociation to remove a significant number of the interfering ions. Means (30 or 32) for providing a population of electrons (34 or 36) in an ICP-MS (22) may comprise a magnetic field means such as an electric coil, or an electron generating device. The population of electrons has an electron number density (>1011 cm?3 to 1014 cm?3), a free electron energy (>0.01 eV to <5 eV) in a region at a low pressure (<10 Torr), such that for a predetermined path length (1–4 cm) of the ions through the electron population, the interfering ions will preferentially be attenuated by the dissociative recombination process.

Abstract: A linear ion trap includes four electrodes and operates with an asymmetrical trapping field in which the center of the trapping field is displaced from a geometrical center of the trap structure. The asymmetrical trapping field can include a main AC potential providing a quadrupole component and an additional AC potential. The main AC potential is applied between opposing pairs of electrodes and the additional AC potential is applied across one pair of electrodes. The additional AC potential can add a dipole component for rendering the trapping field asymmetrical. The additional AC potential can also add a hexapole component used for nonlinear resonance. A supplementary AC potential can be applied across the same pair of electrodes as the additional AC potential to enhance resonant excitation. The operating point for ejection can be set such that a pure resonance condition can be used to increase the amplitude of ion oscillation preferentially in one direction.

Abstract: A plasma source for a spectrometer includes a plasma torch (10) located within a waveguide or resonant cavity (40) for both the electric and the magnetic field components of a microwave electromagnetic field to excite a plasma (54). This produces a plasma (54) having a generally elliptical cross section into which sample is relatively easily injected but which still provides good thermal coupling between the plasma and the sample. The invention gives significantly improved limits of detection compared to prior art microwave induced plasma systems. The torch is preferably axially aligned with the direction of the magnetic field component and may be located within a resonant iris (32) within the waveguide or cavity (40).