Method for formation of two-dimensional liner electric field and device for its implementation

FIELD: electricity.

SUBSTANCE: method for formation of two-dimensional linear electric fields consists in formation of one coordinate of potential average value distribution per working area border using device from flat discrete and hyperbolic electrodes. Flat discrete electrodes consist of thin earthed metal fibres evenly arranged on area borders, and hyperbolic electrodes singly arranged in each quadrant have small sizes of half-axes. Under impact of opposite potentials on adjacent hyperbolic electrodes in planes of discrete electrodes there formed are linear per each axis of potential average value distribution, under their impact in working area there formed is two-dimension linear field.

EFFECT: minimising sizes and improving design-process parameters of electrode systems for formation of two-dimension linear electric fields with working areas expanded along one axis.

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The invention relates to the fields of electron-ion optics and mass spectrometry, based on the motion of charged particles in static and variable two-dimensional linear electric fields, and can be used to improve design and manufacturing technology devices spatio-temporal focusing and mass separation of charged particles. Hyperbolic electrode system is not effective for building mass analyzers with extended along one axis working area because of the considerable size of the electrodes on all the coordinates [1]. The task system of flat electrodes with discrete-linear potential distribution [2], with discrete-varying electric transparency [3] and discrete-variable charge density [4]. The technical problem of the invention is to improve the structural and technological characteristics of the devices of formation of two-dimensional linear electric fields extended along one axis working area, using hyperbolic and flat discrete equipotential electrodes.

Two-dimensional linear electric field in the workspace size 2x_c, 2y_cL X, Y, Z under the condition y_c>>x_cyou can form using discrete flat surfaces of requirementsall routashi elements, distributed along the Y-axis with a constant step ∆y [2] or equipotential conductive elements are unevenly distributed along the Y-axis [3, 4]. Closest to the claimed solution is the method described in [4], which consists in the formation of linear electric field using equipotential elements are unevenly distributed along the axis Y. However, the disadvantages of these systems is the difficulty of design and technological nature, which would complicate the manufacturing process of the ion-optical devices and analyzers ions using a flat discrete electrodes.

In all cases when using the flat of discrete electrodes education two-dimensional linear in the XOY-plane electric fields is to create at region boundaries x=±x_clinear along the Y-axis distributions of the average potential values:

$${\phi }_{\mathrm{with\; a}p}(y_i)=\frac{1}{\Delta y_i}{\displaystyle \underset{y_i-\Delta y/2}{\overset{y_i+\Delta y/2}{\int }}}{\phi }_{\partial i}(y)dy=\frac{msub>\phi mcp}{y_c}{y}_i,\left(1\right)$$

where φ_∂i(y) is the potential distribution in the planes x=±x_cthe i-th discrete element, ∆y_i- step discrete electrodes, φ_MCP=φ_cf(y_c).

For the practical implementation of the ion-optical systems with two-dimensional linear electric fields are of interest, the use of discrete flat surfaces formed from uniformly distributed along the Y-axis with a step of ∆y, parallel to the Z axis, the same equipotential conductive elements (strands or strips. However, using only discrete flat with a constant step ∆y equipotential surfaces does not solve the problem of the formation of two-dimensional linear electric fields. The problem is solved by using the additional 4 hyperbolic potential surfaces, allowing you to create the linear Y-axis distribution of the average value of the potential in the planes x=±x_cdiscrete surfaces. Hyperbolic surface 2 is placed in the region |x|>x_cand on the adjacent surfaces establish the opposite potentials φ ₀and-φ₀(Figure 1). The presence of discrete surfaces 1 allows to displace the origin of the hyperbolic surfaces 2 on the X-axis at a distance x₀for surfaces in the I and IV quadrants and the distance x₀for surfaces in the II and III quadrants and thereby substantially reduce the value of their geometrical parameter r₀- valid axis of hyperbole. The offset value is determined by the ratio:

$$x_0\approx x_c-\mathrm{0,45}\Delta y.\left(\text{2}\right)$$

Hyperbolic surfaces in this case are described by the equation:

$$y=\pm r_0^2/2(x\pm x_0).\left(\text{3}\right)$$

Under the action of opposite potentials φ₀and-φ₀on related hyperbolic surfaces in the cross sections x=±x_cformed potential distribution φ(±x_c,y) - (curve 1, Figure 2), average values for which φ_cf(±x_c,y) if condition (2)will change the Xia linearly (curve 2, Figure 2):

$${\phi }_{\mathrm{with\; a}p}(x_c,y)=E_m\cdot y,\left(\text{4}\right)$$

where$$E_m=0.9\Delta y{\phi }_0/r_0^2$$. In workspace |x|<x_c, |y|<y_cformed field potential distribution of the form:

$$\phi (x,y)=\frac{E_m}{x_c}xy,\left(\text{5}\right)$$

which corresponds to the two-dimensional linear electric field with the projections of the field strength on the axis X and Y:

From (5) and (6) it follows that the system of 2 flat with a constant step ∆y equipotential discrete and 4 hyperbolic surfaces allows to form a two-dimensional linear electric field in workspaces 4 |x|<x_c, |y_c|<y with an arbitrary value of x_c, y_c. Moreover, when the fixed length of the semiaxes r₀hyperbolic surfaces the choice of parameters x_cand ∆y are the dimensions of the stage along the X-axis can vary within wide limits.

Device for the formation of two-dimensional linear electric field on the proposed in claim 1 of the formula of the invention the method consists of 2 flat discrete electrodes 1 L>>2x_cand 4 hyperbolic electrodes 2 L>>2x_c(Figure 1). Discrete electrodes 1 with the size of y_a>>x_con the Y-axis are located in the planes x=±x_cand formed from uniformly distributed along the Y-axis with a step of ∆y thin diameter d<<∆y parallel to the axis Z of the equipotential threads. The origin of the hyperbolic electrodes are shifted in pairs on the X-axis at a distance of ±x₀and have the final coordinates x=±x_ay=±y_awhere x_a≥(x_c+1.5₀), y_a≥(y_c+1.5x_c). Hyperbolic electrodes are located outside of the RA the eyes region 4 (figure 1) |x|> x_cone in each quadrant. Geometric parameter r₀hyperbolic electrodes is determined by the step discontinuity ∆y flat electrodes and their size y_aaxis Y:

$$r_0=\sqrt{2y_a\Delta y}$$.

For the given parameters x_c, y_cworkspace geometric parameter r₀hyperbolic electrodes used in conjunction with discrete flat electrodes with a constant step value ∆y, is significantly less than the parameter r₀hyperbolic electrodes 3 (Fig 1)that generates the same field in the absence of discrete electrodes. This allows the analyzer elongated along the Y-axis workspaces 4 (figure 1), when y_c>>x_cby minimizing the value of the parameter r₀hyperbolic electrodes in 2-2,5 times to reduce the size of the electrode systems of analyzers on x-axis Dimension L of the electrodes 1 and 2 along the Z axis is chosen based on the acceptable level of deviation of the field from the line in the workspace of the analyzer due to edge effects:

L≥4x_c.

Use as a flat discrete electrodes evenly distributed along the Y-axis metal thread in conjunction with hyperbolic electrodes. the em design and manufacturing technology, and also reduces the size analyzers with two-dimensional linear electric fields.

LITERATURE

1. Gurov B.C., Mammoths E.V., Diaghilev A.A. Electrode system with a discrete linear distribution of high frequency potential for mass analyzers charged particles // Mass spectrometry. 2007. No. 4 (2). - S-142.

2. Patent RU No. 2327245 from 03.05.2006, the Way mass-selective analysis of ions by time-of-flight and device for its implementation.

3. Patent RU No. 2387043 from 10.04.2008, the Method of forming the linear field and a device for its implementation.

4. Patent RU No. 2422939 from 25.11.2009, the Method of forming a two-dimensional linear electric field and the device for its implementation.

1. The method of forming a two-dimensional linear electric field, which consists in creating the boundaries x=±x_cworkspace |x|<x_c, |y|<y_cparallel to the axis Z plane discrete conductive surfaces with sizes 2y_aL Y, Z, composed by distributed along the Y-axis parallel to the Z-axis of the thin conductive filaments, wherein the Y-axis equipotential threads evenly distributed increments Δy, and the edges of the stage |x|>x_chave one in each quadrant of the hyperbolic conductive surface$$y=\pm r_0^{2}mo>\; /2(x\pm x_0)$$where |x₀|<|x_c|, r₀- the real axis of hyperbole, and on the adjacent surfaces set opposite potentials φ₀and-φ₀.

2. Device for the formation of two-dimensional linear electric field that contains the edges of the stage x=±x_cparallel to the Z axis electrodes of length L>>2x_cfrom distributed along the Y-axis parallel to the Z-axis conductive thin filaments, characterized in that use two in the planes x=±x_cdiscrete size y_a>>x_con the Y-axis electrode of evenly spaced increments Δy along the Y-axis equipotential threads with a diameter of d<<Δy and four, one in each quadrant, hyperbolic electrode with a valid radius r₀shifted in pairs on the X-axis at a distance of ±x₀with a final coordinates x=±x_a,
y=±y_awhere x_a≥(x_c+1,5r₀), y_a≥(y_c+1,5x_c).