Mass selective device and analysis method for drift time of ions
 Dust impact mass spectrometer / 2326465Invention relates to the instrument engineering, automation means, and control systems, namely, to the space research area. The dust impact mass spectrometer contains a hemispheric target with one opening in the middle of its surface, which increases the probability of target impact with a micrometeorite at the same dimensions of the mass spectrometer. The accelerating gap is a limited by a hemispheric target and a hemispheric grid, located concentrically, which provides equal ion trajectory lengths, thus eliminating the measurement result dependence on the impact location and increases the measurement result reliability. The parabolic reflector focuses ions into a parallel beam directed exactly to the hemispheric target opening. |
 Transit-time method for metering charge and mass composition of plasma ions / 2314594Proposed method involves immersion of drift tube into plasma followed by acceleration of ions by applying negative-polarity voltage pulse across drift tube, pulse length being shorter than its transit time within drift tube carrying analyzed plasma accelerated ions at highest Z/Mi ratio, where Z is degree of ion charge in plasma; Mi is ion mass; this is followed by separating ions with respect to their mass, charge, and energy as they are conveyed through equipotential space of drift tube, as well as measurement of ion current pulse at drift tube outlet; then second measurement similar to first one is made but for different length of negative-polarity voltage pulse supplied to drift tube; charge and mass composition of plasma ions is evaluated by subtracting results of measuring ion current pulses at outlet of drift tube obtained at different lengths of negative-polarity voltage pulses. |
 Transit-time mass spectrometer / 2295797Proposed mass spectrometer that can be used for solving problems in organic chemistry, biochemistry, immunology, medicine, biotechnology, environment control, for evaluating composition and properties of materials in industry and scientific research has pulsed ion source, drift space with two flat braking-field wire-net capacitors and detector installed in tandem at its end is provided with second drift space formed by common electrodes of flat wire-net capacitors spaced along device axis; potential of second drift space is braking one with respect to first drift space. |
 Analyzer of energies of charged particles / 2294579Analyzer of charged particles energy contains sample (emitting charged particles), external electrode and internal electrode with two circular slits and detecting system. Axial and radial gradients of energy analyzer field potential are synchronized along movement route of charged particles by setting appropriate configuration of equipotential surfaces of analyzer electrodes. |
 Ion spectrum measurement process and transit-time ion spectrometer / 2266587Charge and mass composition is measured by accelerating ions in accelerating gap formed in vacuum chamber between input end of drift tube and plasma when negative-polarity voltage pulse of length shorter than transit time in drift tube of accelerated ions of plasma being analyzed is applied to drift tube at maximal Z/Mi ratio, where Z is ion charge in plasma; Mi is ion mass. Voltage pulse is supplied from negative-polarity accelerating-voltage pulse source whose high-voltage lead is electrically connected to drift tube and other lead, to vacuum-chamber ground. When in transit, accelerated ions are divided within drift tube into mass, charge, and energy clots and separated clots are recorded by detector. |
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Ion spectrum measurement process and transit-time ion spectrometer / 2266587 Charge and mass composition is measured by accelerating ions in accelerating gap formed in vacuum chamber between input end of drift tube and plasma when negative-polarity voltage pulse of length shorter than transit time in drift tube of accelerated ions of plasma being analyzed is applied to drift tube at maximal Z/Mi ratio, where Z is ion charge in plasma; Mi is ion mass. Voltage pulse is supplied from negative-polarity accelerating-voltage pulse source whose high-voltage lead is electrically connected to drift tube and other lead, to vacuum-chamber ground. When in transit, accelerated ions are divided within drift tube into mass, charge, and energy clots and separated clots are recorded by detector. |
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Analyzer of energies of charged particles / 2294579 Analyzer of charged particles energy contains sample (emitting charged particles), external electrode and internal electrode with two circular slits and detecting system. Axial and radial gradients of energy analyzer field potential are synchronized along movement route of charged particles by setting appropriate configuration of equipotential surfaces of analyzer electrodes. |
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Transit-time mass spectrometer / 2295797 Proposed mass spectrometer that can be used for solving problems in organic chemistry, biochemistry, immunology, medicine, biotechnology, environment control, for evaluating composition and properties of materials in industry and scientific research has pulsed ion source, drift space with two flat braking-field wire-net capacitors and detector installed in tandem at its end is provided with second drift space formed by common electrodes of flat wire-net capacitors spaced along device axis; potential of second drift space is braking one with respect to first drift space. |
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Transit-time method for metering charge and mass composition of plasma ions / 2314594 Proposed method involves immersion of drift tube into plasma followed by acceleration of ions by applying negative-polarity voltage pulse across drift tube, pulse length being shorter than its transit time within drift tube carrying analyzed plasma accelerated ions at highest Z/Mi ratio, where Z is degree of ion charge in plasma; Mi is ion mass; this is followed by separating ions with respect to their mass, charge, and energy as they are conveyed through equipotential space of drift tube, as well as measurement of ion current pulse at drift tube outlet; then second measurement similar to first one is made but for different length of negative-polarity voltage pulse supplied to drift tube; charge and mass composition of plasma ions is evaluated by subtracting results of measuring ion current pulses at outlet of drift tube obtained at different lengths of negative-polarity voltage pulses. |
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Dust impact mass spectrometer / 2326465 Invention relates to the instrument engineering, automation means, and control systems, namely, to the space research area. The dust impact mass spectrometer contains a hemispheric target with one opening in the middle of its surface, which increases the probability of target impact with a micrometeorite at the same dimensions of the mass spectrometer. The accelerating gap is a limited by a hemispheric target and a hemispheric grid, located concentrically, which provides equal ion trajectory lengths, thus eliminating the measurement result dependence on the impact location and increases the measurement result reliability. The parabolic reflector focuses ions into a parallel beam directed exactly to the hemispheric target opening. |
 Mass selective device and analysis method for drift time of ions / 2327245Invention pertains to the field of dynamic mass analysis of charged particles in alternating HF fields. The mass-selective method of separating ions is based on the use of an analyser, consisting of two flat parallel electrodes with linear-discrete and anti-phased HF potential distributions on the Y axis and a flat earthed electrode, and a limiting electrode with values y≥0. The discrete electrodes are made in the form of capacitor or inductive linear HF voltage dividers. Applied to the electrodes are two anti-phased HF voltages with constant amplitude Um and frequency, ω for which a linear alternating electrical field is formed in the analyser on the X and Y axis. Ions are put into the analyser through the opening in the flat earthed electrode with initial coordinates xn>0, уn=0 and initial velocities vu, inversely proportional to the masses, m of the analysed ions. Ions on the X and Y axes have almost harmonic oscillations with the same amplitude уm and period T, proportional to mass m. During the analysis period the x coordinate of the ions changes to the opposite x(tA)=-xn, while the y coordinate becomes equal to y(tA)=0. The sorted out ions in accordance of their mass m, successively pass into the analyser and reach the registration system. |
 Ion mobility spectrometer / 2328791Ion mobility spectrometer contains the neoformation chamber with installed ion source, drift chamber with the ion collector and aperture mesh, ejecting electrode and the mesh gate which form the ejection area, holes for supplying the mixture of the analised substance with carrier gas, and drifting gas and for outputting the drift gas and the mixture of the analised substance with carrier gas. The chamber of ion-formation with the ion source is placed out of the ejection area and connected with it via adapter with the canal for ion transportation; at that, the ion-formation chamber has the potential of the mesh gate. The adaptor canal has the conical shape, at the ion-formation chamber, which becomes slit-like at the ejection area. The planes of the slit-like canal are parallel to the mesh gate. The length of the slit-like canal is selected so as to guide the ion and carrier gas flow along the ejecting electrode and the mesh gate. The length of the slit-like canal is more or equal to the canal's width, and the canal's width is equal to or less than the distance between the mesh gate and the ejecting electrode. |
 Method and device for identification of organic compounds / 2329563Invention is related to the field of gas analysis, in particular of vapours of explosive, narcotic and poisoning substances. Method of organic compounds identification consists in measurement of volt-ampere characteristics with application of surface-ionisation source of ions, in which measurement of volt-ampere dependence is carried out in interval of voltages "thermal emitter of ions - electrode for ion current control" from U1 to U4, volt-ampere dependence section is separated from U2 to U3>U1, in which value of current of organic compounds ions quadratically depends on value of voltage "thermal emitter of ions - electrode for ion current control", at that U1 and U4 are selected based on conditions U4>U3, U1<U2, at that volt-ampere dependence is used for determination of value of organic compounds ions drift mobility and/or for determination of energy activation value of organic compounds molecules ionisation on thermal emitter surface, at that for determination of organic compounds ions drift mobility value section is used from U2 to U3 of volt-ampere characteristic, and for determination of energy activation value of organic compounds molecules ionisation section is used from U3 to U4 of volt-ampere characteristic. Device is suggested for identification of organic compounds, which contains two structurally identical surface-ionisation sources of organic compounds ions, at that inlet openings of channels of nozzles for intake of analysed air flows of the first and second sources of ions are combined into common channel of common nozzle for intake of analysed air flow. |
 Mass spectrometer for macromolecule analysis / 2332748Mass spectrometer contains holder with analysed substance, ionisator and supplier of macromolecules to mass analyser, and detector. Mass analyser is connected to holder with analysed substance, and detector is based on matrix of micromechanical cantilevers providing determination of interaction time point and point where accelerated macromolecule contacts with petal surface of micromechanical cantilever, providing macromolecule pulse transfer to micromechanical cantilever petal, and following deviation of petal by the distance determined by weight and energy of macromolecule. Thus detector is implemented within consistently optically connected emitting sources, collimating optics, micromechanical cantilever matrix, projecting optics and photodetector, while micromechanical cantilever matrix thereof is designed as detector substrate where micromechanical cantilevers are mounted, thus micromechanical cantilever is designed as part of leg, arm, reflecting layer. Micromechanical cantilever matrix is multielement. |
 Mass-sensitive selective concentrator for ion mobility spectroscopy (ims) / 2379678Invention relates to analytical instruments, particularly, to devices intended for preliminary concentration of analyzed sample and combined with analytical instrument that can be used to produce fast-operation analyzers of poisonous or explosive substance concentration in air. Proposed concentrator comprises analyzed sample fast-desorption absorbing element and acoustic transducer with its output signal depending upon mass of absorbed sample. Acoustic transducer represents a piezoelectric plate-sound conductor with two built-in interdigital electromechanical transducers (IDT), designed to excite and receive surface acoustic waves (SAW). While absorbing element represents a film made from molecular imprinting polymer applied onto said plate-sound receiver surface and consisting of two sections, i.e. small-area detecting section located on SAW propagation line, and larger-area concentrating section located outside acoustic line. Said concentrating section can comprise two additional sections to double as SAW-absorbing coatings. To this end, said additional sections are arranged on plate-sound receiver surface, on SAW propagation line outside the space between IDT. |
FIELD: physics.
SUBSTANCE: invention pertains to the field of dynamic mass analysis of charged particles in alternating HF fields. The mass-selective method of separating ions is based on the use of an analyser, consisting of two flat parallel electrodes with linear-discrete and anti-phased HF potential distributions on the Y axis and a flat earthed electrode, and a limiting electrode with values y≥0. The discrete electrodes are made in the form of capacitor or inductive linear HF voltage dividers. Applied to the electrodes are two anti-phased HF voltages with constant amplitude Um and frequency, ω for which a linear alternating electrical field is formed in the analyser on the X and Y axis. Ions are put into the analyser through the opening in the flat earthed electrode with initial coordinates xn>0, уn=0 and initial velocities vu, inversely proportional to the masses, m of the analysed ions. Ions on the X and Y axes have almost harmonic oscillations with the same amplitude уm and period T, proportional to mass m. During the analysis period the x coordinate of the ions changes to the opposite x(tA)=-xn, while the y coordinate becomes equal to y(tA)=0. The sorted out ions in accordance of their mass m, successively pass into the analyser and reach the registration system.
EFFECT: improved analytic characteristics of hyperboloidal and drift type mass spectrometers.
2 cl, 2 dwg
The invention relates to the field of dynamic mass analysis of charged particles in the variables RF fields and can be used to improve analytical, operational and consumer properties of mass spectrometers hyperboloid and time-of-flight type. In known hyperboloid mass spectrometers scan mass is carried out sequentially, the speed of the analysis is low, and sweep the masses want to change in time the amplitude or the frequency of the RF voltage. High speed analysis time-of-flight mass spectrometers with static electric fields are sensitive to the range of initial energies and angles of incidence of the analyzed ions. For the prototype accepted dynamic mass analyzers with a quadratic distribution of the RF potential on the two coordinates [1] and mass analyzers, time-of-flight type static fields [2]. The technical problem of the invention consists in the improvement of the methods of mass analysis of charged particles and designs analyzers using mass-selective sorting of ions in a two-dimensional linear RF fields.
The proposed method of mass-selective analysis of ions by time-of-flight based on the formation of the boundary surface x=x0and x=-x0mass analyzer two anti-Christ. asnyk discrete linear increments Δ ϕ coordinate the distribution of the RF potential
where n=0, 1, 2,...N is the number of discrete surface elements, N=Ly/d is the number of discrete surface elements, yn=n·d - coordinate of the n-th element, d is the distance between adjacent elements. Provided that the dimensions of the analyzer Lyand LzY and Z are large enough, Ly>>x0, Lz>4x0the potential distribution in the field of sorting ions with high accuracy will be described by the expression
The potential distribution (2) correspond to linear in the coordinates x and y of the distribution of the electric field strength
For small values of the parameterwhere e and m are the charge and mass of the ion, the movement of charged particles with coordinates 0<xn<x0, yn=0 and the initial velocity
X and Y will be described with functions similar to those of a harmonic
The function described by the expression (4)have a period
For setting time-of-flight mass sorting of ions is time tAnd=T/2, for which ions on the Y-axis do return number is Bane from the initial coordinates y n=0 to the final coordinates(T/2)=0, and the X-axis coordinate their changes its sign to the opposite x(T/2)=-xn. While the analysis time is proportional to the mass of the ions
As a device for mass-selective analysis of ions by time-of-flight is proposed to use an electrode system consisting of two discrete Y-axis electrodes 1 and 2 with work surfaces x=x0and x=-x0and the size of Ly>>x0and Lz>4x0Y and Z, and one solid electrode 3 with dimensions of Lx>20and Lzand the working surface in the plane y=0 (Figure 1). Discrete electrodes 1 and 2 are performed, or in the form of two sets of N=Ly/d flat, wide l>>d and length Lzevenly distributed along the Y-axis in increments of d parallel plates forming two linear capacitive divider the RF voltage, or in the form of a flat single-layer parts with a uniform pitch d of the coil winding two coils of N turns each, forming two linear inductive divider the RF voltage. To the electrodes 1 and 2 included two anti-phase harmonic voltage with constant amplitude Umand frequency ω
Divisors of the RF voltage creates on the working surfaces x=x0and x=-x0electrodes 1 and 2 discrete-inania Y-axis distribution of the RF potential. A grounded electrode 3 with zero potential ϕ3=0 restricts the space of sorting by the Y-axis the values area we≥0. The electrode 3 has a slit width Δx<<x0length Δz<x0/2 with center coordinates (x0/2<xy<x0, zy=0, through which the ions enter into the scope for the sort of mass analyzer. Output the sorted ions from the mass analyzer is through the hole in the electrode 3 with a diameter of D<x0/2 with center coordinates (xresp=-xy, zresp=0.
The cycle of mass analysis begins with education outside the field of sorting ions with initial coordinates x0/2<xn<x0,n=0,initial velocities along the Y-axis, inversely proportional to the mass analyzed ions vy≈eΔϕLy/(2ωx0m), and along the axes X and Z with small velocities vxvz<<vy. Then ions within a short period of time tin<<tAinserted through a slit in the electrode 3 in scope for the sort of mass analyzer. During the simulation time tAproportional to the mass m of the analyzed ions, charged particles do in the two-dimensional linear RF field return with the same amplitudes inm<Lyvariations on the y coordinate and then sequentially what about the time in accordance with the mass m of the ions through the hole in the electrode 3 are derived from the mass analyzer and enter the registration system.
The proposed method of mass-selective sorting of ions in a two-dimensional linear RF field by time-of-flight and device for its implementation are temporal focusing of the ions with different initial coordinates X and Z, energies, angles and phases of incidence, which improves the analytical characteristics of the mass spectrometers span type. Efficient design of the electrode system of the proposed time-of-flight mass analyzer and an easy way RF power improve operational and consumer parameters of the devices of this type.
Figure 1. Electrode system time-of-flight mass analyzer
a) with linear capacitive RF dividers, b) with a linear inductive dividers RF voltage.
Figure 2. Way RF power and trajectory of ions in time-of-flight mass analyzer with discrete electrodes
Literature
1. ..Dawson "Quadrupole Mass Spectrometry and Its Applications", Elsevier, Amsterdam, 1976.
2. Nudeskin, Iviana, Cesarano, Rauchmelder. Prospects for the development of time-of-flight mass spectrometers for the analysis of gas and dust particles. Applied physics, 2002, No. 2, p.124-141.
1. The way mass-selective analysis of ions by time-of-flight in a linear RF field, characterized in that the boundary surface x=x0and x=-x0mass analyzer of size Ly>>x0and Lz>4xsub> 0Y and Z under the action of two opposite phase voltage with constant amplitude Umand frequency ω creates two anti-phase discrete-linear Y-axis distribution of the RF potential and the ions formed from the initial coordinates x0/2<xn<x0,n=0, |zn|<x0/2 and the initial velocity vyon the Y-axis, inversely proportional to the mass m of the analyzed ions, linear effect on the X and Y axes of the RF field, while ions for time tAproportional to the mass m, do X and Y are close to harmonic oscillations with finite coordinates x(tA)=-xn, y(tA)=yn=0.
2. Device for mass-selective analysis of ions by time-of-flight containing an electrode system for creating a workspace mass analyzer two-dimensional linear field, characterized in that the electrode system of the mass analyzer using two restricted by the plane y=0 discrete Y-axis with a pitch d of the electrode 1 and 2 of size Lyand LzY and Z lying in planes x=x0and x=-x0made or as sets of evenly spaced increments of d flat metal plates or in the form of flat pieces of uniform increments of d-layer coil winding inductors, and a grounded electrode 3 with the working surface of the plane y=0, moreover, in the electrode 3 has a slot for entering of ions of a width of Δx<<x0length Δz<x0/2 with center coordinates (xy<x0, zy=0 and a hole for o ions with center coordinates (xresp=-xy, zresp=0.