CN118098910A - Multi-channel quality selector for equivalent kinetic energy voltage cross-polarity correction - Google Patents

Abstract

The invention discloses a multi-channel quality selector for correcting equal kinetic energy voltage cross-polarity, each area consists of upper and lower parallel plate electrodes, a left inlet slit plate, a right inlet slit plate, a vertical plate and an outlet slit plate, wherein the parallel plate electrodes are arranged in parallel, are perpendicular to and attached to the left and right plates, the parallel plate electrodes are externally connected with a high-voltage pulse power supply, the time logic of each voltage pulse is reasonably set, the time logic is collected from bottom to top, an inlet slit is formed at one end of the inlet slit plate, which is close to the lower parallel plate electrode, and an outlet slit is formed at one end of the outlet slit plate, which is close to the lower parallel plate electrode in each area, so that the quality selection of a plurality of single-size cluster particle beams with different qualities is realized, the problem of low particle yield is solved, and the average particle utilization efficiency is improved; the design of the multichannel mass selector is realized by using an equal kinetic energy acceleration mode, and the voltage cross-polarity characteristic is corrected.

Description

Multi-channel quality selector for equivalent kinetic energy voltage cross-polarity correction

Technical Field

The invention belongs to the technical field of atomic molecular physics and nano science, relates to a device widely applied to cluster physical and chemical property research and cluster beam controllable deposition, and in particular relates to a multichannel quality selector for equivalent kinetic energy voltage cross-polarity correction.

Background

The existing single-channel mass selector can only collect the required single particles in parallel, and the particles with small mass differences undergo incomplete acceleration or deceleration pulse, enter a deceleration area and do not strike the upper base plate, are obliquely ejected in the deceleration area, and are sliced in a right collection area to influence the purity of the collected cluster particles. If the emitted particle beam contains particles of various masses, the prior art can only collect a single particle, resulting in the waste of particles of other masses.

The prior art single-channel quality selector can realize the particle selection of a certain fixed quality, but the limitation of the device structure and the fact that cluster particles strike the polar plate can lead to voltage fluctuation, the actual collection effect is affected, the particles with similar quality can also partially affect the final collected purity, and the overall utilization efficiency of the device is not high.

The current solution is as follows:

Filing date, 2017/8/4; application number: CN201621376463.9, patent name: the patent discloses a mass selection device of a cluster and a processing device of the cluster, and relates to the field of instrument assembly. By adopting a multi-layer screening mode, cluster particles entering from an inlet of the mass selector are accelerated by an acceleration zone, then enter a deceleration zone through screening of a flight zone, are ejected from a channel outlet of the mass selector through the deceleration zone, and enter subsequent processing equipment through an ultrahigh vacuum sample conveying system. Through multi-layer screening, the cluster particles with specific quality are precisely separated, the accuracy of quality selection is improved, and the operation of subsequent processing operation is facilitated.

The mass selector is characterized in that the mass selector is a mass selector of a cluster and a processing device of the cluster, the electric field applying device is connected with the mass selector through a power line, the mass selector is provided with a particle selecting cavity, a first electrode plate, a second electrode plate, a third electrode plate and a fourth electrode plate are sequentially arranged in the particle selecting cavity from top to bottom, an acceleration region of the mass selector is formed between the first electrode plate and the second electrode plate, a flight region of the mass selector is formed between the second electrode plate and the third electrode plate, and a deceleration region of the mass selector is formed between the third electrode plate and the fourth electrode plate.

However, the mass selector technique disclosed in this patent can only be used for screening one type of particle, and when there are a plurality of particles of different mass in the particle beam, other particles strike the plate, resulting in waste of material and low particle yield.

Filing date, 2022/8/29; application number: CN202211039446.6, patent name: a multi-channel mass selector with equal momentum and equal kinetic energy acceleration is disclosed, which adopts two acceleration areas, two transition areas and a plurality of deceleration areas to replace three groups of electrode structures of a forward deflection area, a free flight area and a reverse deflection area of cluster ions in the current general cluster flight time mass selector. After entering the selector, the active part of particles passing through the acceleration region obtains the same kinetic energy, the other part of particles obtains the same momentum, after reading the intermediate transition region, the particles with different masses enter the corresponding deceleration region, and the y-direction speeds of the different particles are reduced to zero in the corresponding region by adjusting the pole plate voltage of the deceleration region, so that the particles fly horizontally at the outlet.

The cluster mass selector aims at a transverse flight time cluster mass selector and a using method thereof, and adopts a structure that a plurality of pairs of parallel plate electrodes replace three groups of electrodes of a cluster ion forward deflection area, a free flight area and a reverse deflection area in the current common cluster flight time mass selector, so that the selector can select particles with different masses.

However, the technology mentioned in the patent adopts a mode of combining equal kinetic energy and equal momentum, the design of a transition zone is longer, the length of a deceleration zone is related to the mass of particles, the length is different and complex, the whole width of the device reaches more than 10000mm, and the size of the device is oversized.

Disclosure of Invention

In order to solve the problems, the invention discloses a multi-channel quality selector for equal kinetic energy voltage polarity-crossing correction, which solves the problem of low particle yield, improves the particle passing rate, optimizes the design of a transition area and a deceleration area by adopting an equal kinetic energy mode, and simplifies the overall size of a multi-channel quality selecting device.

In order to achieve the above purpose, the technical scheme of the invention is as follows:

A multi-channel mass selector for cross-polarity correction of equivalent kinetic energy voltage is arranged in a vacuum cavity and comprises parallel plate electrodes, an inlet slit plate, an outlet slit plate and a vertical plate, 1 accelerating area, 3 transition areas and a plurality of decelerating areas are formed, parallel plate electrodes on the upper side and the lower side of each area are arranged in parallel, one side of each accelerating area is the inlet slit plate, the other side of each decelerating area is the vertical plate, one side of each decelerating area is the outlet slit plate, the other side of each decelerating area is the vertical plate, the two sides of the other areas are vertical plates, the parallel plate electrodes are perpendicular to and attached to corresponding plates on the left side and the right side, the parallel plate electrodes are externally connected with a high-voltage pulse power supply, one end of each inlet slit plate, which is close to the lower parallel plate electrode, is provided with an outlet slit, and the other areas are electrically insulated;

the acceleration region adjusts pulse voltages of the acceleration region and the transition region according to the selected particle range, so that all the selected particles obtain the same kinetic energy;

The accelerating area consists of an upper parallel plate and a lower parallel plate, the upper parallel plate is connected with transition pulse voltage, the accelerating pulse voltage is applied to the lower parallel plate, the electric field direction is vertically upward, the cluster particles are accelerated to move upward under a uniform electric field, the speed in the vertical direction is obtained, and the accelerating time is longer than the time from the time that the mass maximum particle selected at the time is always accelerated to move in the accelerating area until leaving;

The transition area is used for realizing the transition of the pulse voltage amplitude from the acceleration area to the deceleration area;

The transition pulse voltage is applied to the upper parallel plate, the lower parallel plate, the left parallel plate and the right parallel plate of the corresponding transition zone, so that the transition of the pulse voltage amplitude from the voltage amplitude of the acceleration zone to the voltage amplitude of the deceleration zone is realized;

The deceleration zone is used for changing the vertical speed of the selected particles to 0, so that the particles fly along the horizontal direction, and the selected particles with the preset quality are obtained from the outlet slit;

In each layer of deceleration zone, deceleration pulse is applied to the parallel plates on the deceleration zone n, the electric field direction is vertically downward, and the duration of the pulse is the deceleration motion of the particles selected by the layer in the deceleration zone until the speed in the vertical direction is 0.

As a further improvement of the invention, the parallel plate electrode, the inlet slit plate, the outlet slit plate and the vertical plate are all made of aluminum.

As a further improvement of the invention, the parallel plate electrode has a length of 7000mm to 9000mm, a width of 2500mm and a thickness of 3mm.

As a further improvement of the invention, the interval between the inner surfaces of the two parallel plate electrodes in the transition zone 2 is 1400mm, the interval between the inner surfaces of the two parallel plate electrodes in the transition zone 1 is 50mm, and the interval between the inner surfaces of the two parallel plate electrodes in the other respective zones is 150mm.

As a further improvement of the invention, the slit lengths of the inlet slit plate and the outlet slit plate are 2000mm, and the widths are 2mm-10mm.

As a further improvement of the present invention, the distance between the center line of the inlet slit and the inner surface of the lower parallel plate of the acceleration section 1 is 12mm, and the distance between the center line of the outlet slit of each layer n from the deceleration section 1 and the inner surface of the lower parallel plate electrode of the deceleration section is 12mm.

The invention has the beneficial effects that:

The multi-channel quality selector for the equivalent kinetic energy voltage cross-polarity correction realizes the quality selection of the same-element particles with various qualities, so that the original experiment can only collect the particles with one quality until the present experiment can collect the quality of a plurality of particles, and the problem of low particle yield is solved; by reasonably setting the time logic of each voltage pulse and collecting the voltage pulses from bottom to top, the average utilization efficiency of a plurality of cluster particles can be improved; the design of the three transition areas isolates the influence of sudden voltage changes on the particle acceleration area and the AU1 deceleration area, so that the stability is enhanced; the magnitude and waveform of the voltage is not complex, and the decelerating voltage pulse of one mass particle does not affect the particle trajectories of the other masses.

Drawings

FIG. 1 is a schematic cross-sectional view of a multi-channel mass selector for cross-polarity correction of a voltage with equivalent kinetic energy according to the present invention;

FIG. 2 is a schematic diagram of a prior art single channel mass selector with voltage applied to 4 metal plates on which the present invention is based;

Wherein 1, 2,3 and 4 are parallel plate electrodes, a is the distance of the movement of the particle beam during the acceleration high-voltage pulse, b is the distance of the upward uniform flight of the particles, and c is the distance of the movement of the particle beam during the deceleration high-voltage pulse;

FIG. 3 is a diagram of gold particle trajectories in accordance with the present invention;

FIG. 4 is a diagram of a single particle motion trajectory of the present invention;

FIG. 5 is a velocity vs. time plot of gold particles in a direction perpendicular to the direction of incidence in the present invention;

FIG. 6 is a schematic diagram of setting the accelerating pulse voltage;

FIG. 7 is a schematic diagram of the setting of the transition pulse voltage;

FIG. 8 is a schematic diagram of the setting of the deceleration pulse voltage;

FIG. 9 is a graph of particle motion trajectories over time in accordance with the present invention;

FIG. 10 is a table comparing actual passage rate of particles with theoretical value.

Detailed Description

The present invention is further illustrated in the following drawings and detailed description, which are to be understood as being merely illustrative of the invention and not limiting the scope of the invention.

The invention provides a design structure of a multi-channel mass selector for cross-polarity correction of equivalent kinetic energy voltage, which is shown in figure 1, and the device comprises parallel plate electrodes, an inlet slit plate, an outlet slit plate and a vertical plate. The parallel plate electrode, the inlet slit plate, the outlet slit plate and the vertical plate are all made of aluminum;

The length of the parallel plate electrode is 7000mm-9000mm, the width is 2500mm, the thickness is 3mm, the distance between the inner surfaces of the two parallel plate electrodes is 50mm-1400mm, except that the transition zone 1 is 50mm, the distance between the inner surfaces of the two parallel plate electrodes in the transition zone 2 is 1400mm, and the distance between the other areas is 150mm. The inlet slit plate, the outlet slit plate and the vertical plate are perpendicular to the parallel plates and are attached, the slit length is 2000mm, and the width is 2mm-10mm. The plates are kept electrically insulated; the distance between the center line of the entrance slit and the inner surface of the lower parallel plate of the acceleration section 1 was 12mm, and the distance between the center line of the exit slit of each layer n from the deceleration section 1 and the inner surface of the lower parallel plate electrode of the deceleration section was 12mm. The selector is arranged in the vacuum cavity.

The invention provides a design method of a multi-channel quality selector for cross-polarity correction of equivalent kinetic energy voltage, which comprises the following steps:

all particles undergo a complete acceleration and deceleration process in the direction perpendicular to the incidence direction (namely the vertical movement direction) of the particle beam, the speed change quantity of the acceleration and deceleration processes is consistent, the particles with various masses are not interfered with each other, and the particles with various masses can fly out and be collected horizontally;

Different movement areas are divided according to different particle movement processes, and 1 acceleration area is provided: the constant kinetic energy accelerating area, the 3 transition areas and the plurality of decelerating areas, the pulse periods added in each area are equal, and the amplitude is-2500V-8000V;

Pulse voltages of the acceleration region and the transition region are regulated according to the selected particle range, so that the same kinetic energy is obtained;

according to different particle masses, pulse voltages of corresponding deceleration zones are adjusted, particles fly along a horizontal flight path, and particles with selected preset masses are obtained from an outlet slit.

The working principle of the multichannel quality selector for correcting the cross polarity of the equivalent kinetic energy voltage is as follows: under a constant electric field, all charged particles of the mass travel along the same flight path between the parallel electrodes, and therefore mass separation of the charged particles cannot be achieved by a constant transverse electric field. But the time required for charged particles of different masses to fly through a defined path is related to their mass. This makes the actual flight path of the charged particles between the parallel plate electrodes under a pulsed electric field with a defined pulse width dependent on its mass. As shown in fig. 3, there are n different flight times for all particles. In the time period of t 0-t 1, the potential difference between the two polar plates is zero, after the cluster particles enter the parallel plate electrode area from the inlet slit, the cluster particles fly parallel to the plane of the electrode, and in the time period of t1-t2, the particles accelerate to move and are divided into two sections: the positive charged clusters will first undergo a lateral acceleration flight perpendicular to the plane of the electrodes, beginning with an acceleration pulse t ₁-t₂₁; at time period t ₂₁-t₂, the acceleration pulse 1 is ended, the particles keep a fixed speed and fly upwards in an inclined way until Au30 flies out of the acceleration region, and the kinetic energy of all the particles is the same. All particles fly upwards at a constant speed in the period of t2-t3 until reaching the collecting layer of each particle, the particles start decelerating in the period of t3-t4 until the vertical speed of the particles is reduced to 0, and fly for a certain time at a constant speed in the period of t4-t5 until reaching the outlet slit of the layer. The motion profile of the individual particles is shown in fig. 4. Since clusters of different masses have different lateral flight accelerations, their lateral flight distances are different in the same flight time, which results in clusters of different masses whose flight paths no longer coincide after time t ₂₁.

The ratio of the t0-t1 period to the pulse period determines the percentage of clusters of a given mass that can be selected from among the total number of such mass clusters generated by the cluster source, i.e., the maximum pass rate R _max of mass selection. The pass rate can be calculated by the following formula:

deltat ₁ is the time length of the T0-T1 time period, and T is the pulse period.

The following describes the embodiments of the present invention in detail (taking gold particles, au2 to Au30 as an example).

As shown in figure 1, the structural design of the multi-channel mass selector for the equivalent kinetic energy voltage cross-polarity correction comprises a plurality of parallel plate electrodes with metal meshes of different lengths, an inlet slit plate, an outlet slit plate and a vertical plate, wherein the parallel plate electrodes are parallel to each other. The parallel plate electrode is perpendicular to the slit plate and is attached to the slit plate, and the mass selector is installed in the vacuum cavity. The parallel plate electrode, the inlet slit plate and the outlet slit plate are all made of aluminum; the length of the whole device is uniform, the distance between the inner surfaces of the two parallel plate electrodes is 50mm-1400mm, the distance between the inner surfaces of the two parallel plate electrodes in the transition area 2 is 1400mm except that the distance between the inner surfaces of the two parallel plate electrodes in the transition area 1 is 50mm, and the distance between the other areas is 150mm. The inlet and outlet slit plates were perpendicular to the parallel plates, the slit lengths were 2000mm and the width was 10mm. The plates are kept electrically insulated; the distance between the center line of the inlet slit and the inner surface of the lower parallel plate of the acceleration zone 1 is 12mm, the distance between the center line of the outlet slit of each layer of deceleration zone n from the deceleration zone 1 and the inner surface of the lower parallel plate electrode of the deceleration zone n is 12mm, the lower metal plate of the acceleration zone is connected with a high-voltage acceleration pulse power supply through a vacuum lead flange, the acceleration pulse schematic diagram is shown in fig. 6, the upper, lower, left and right parallel plate electrodes of the transition zone 1 are connected with a high-voltage transition pulse power supply through vacuum lead flanges, and transition pulses are shown in fig. 7; the upper parallel plate electrode of each deceleration area is connected with each layer of high-voltage deceleration pulse power supply through a vacuum lead flange, and a deceleration pulse diagram of Au ₃₀ is shown in figure 8; the high-voltage pulse power supplies apply high-voltage pulses with the same period to the electrode plates respectively.

The design method of the height H of the mass selector comprises the following steps:

the beam is accelerated upward by applying a high voltage acceleration pulse through the bottom plate p2 below the entrance slit of the acceleration region, while the upper bottom plate p1 voltage V ₀ of the acceleration region is constant at-2000V. Let the horizontal kinetic energy of the particle beam entering the mass selection section be E ₀, the horizontal velocity be v _xn, the kinetic energy of the particles in the vertical direction after acceleration be E, and the vertical velocity be v _yn. The potential difference of the acceleration region is U ₀, the potential difference of the deceleration region n is U _n, the distance between the inlet and the upper bottom plate p1 of the acceleration region is d ₀, the height of the acceleration region is d, the height of the uniform speed region is d ₂, and the height of the deceleration region is d ₃.

The acceleration mode of particles is equal-kinetic energy acceleration, and the pulse period of equal-kinetic energy acceleration is shorter, but the particle kinetic energy above and below the particle beam diameter is different, and the problem that the deceleration voltage spans across the voltage polarity exists.

The design structure of the scheme consists of an acceleration region, 3 transition regions and a plurality of deceleration regions, wherein particles acquire the same kinetic energy in the acceleration region.

The Au 2-Au 30 particles are firstly applied with different acceleration time in the acceleration region, and the acceleration pulse is based on that the particles above the heaviest particle beam (Au 30) do not fly out of the acceleration region, so that the Au 1-Au 30 can obtain the same kinetic energy in the acceleration region.

Let the kinetic energy of each particle of mass m _n from the inlet be E ₀, the horizontal velocity be v _xn

Each particle acquires the same kinetic energy after undergoing acceleration by a potential difference fixed at 2000eV in an acceleration region, acquires upward kinetic energy E of 2000eV, and has a vertical velocity v _yn.

So after acceleration, the gold 1-30 particles fly upward with a fixed angle alpha.

The height of the acceleration zone is 0.15m, the height of the transition zone 1 is 0.05m, the height of the transition zone 2 is 1.4m, the height of the transition zone 3 is 0.15m, and the heights of the plurality of deceleration zones n are all 0.15m, so that the overall height of the device is 6.25m.

The whole mass selector device has the length of L, the height of H, the initial voltage of V ₀ (namely the voltage of the upper bottom plate p1 of the acceleration zone), the horizontal kinetic energy of the particle beam entering the mass selection part of E ₀, the horizontal velocity of the particle of V _xn, the kinetic energy of the particle in the vertical direction after leaving the acceleration zone of E and the vertical velocity of the particle of V _yn.

The potential difference when acceleration pulse is applied to the acceleration region is U ₀, the potential difference when pulse is applied to the deceleration region is U ₁, the distance between the inlet and the upper bottom plate of the acceleration region is d ₀, the height of the acceleration region is d, the height of the transition region 1 is d ₁, the height of the transition region 2 is d ₂, the height of the transition region 3 is d ₃, and the heights of the deceleration regions r 1-r 30 are d ₄.

V₀＝-500V,E₀≈500eV,U₀＝2000V

d₀＝12cm,d＝15cm,d₁＝5cm,d₂＝140cm,d₃＝15cm,d₄＝15cm,

H＝d+d₁+d₂+d₃+30d₄＝6.25m

The pulse design method comprises the following steps:

then the length L of the device, the accelerating (decelerating) pulse voltage U ₀(U₁) and the pulse voltage U ₀(U₁ are given according to each time period of the particles, The cluster particles are moved at various stages for a time T _a-n and a period T.

1. Enter t 0-t 1 horizontally at uniform speed

The Au ₁～Au₃₀ particle beam enters the mass selector from the entrance of the acceleration region at time t ₀, undergoes a horizontal uniform motion of duration Δt ₁, and fills the target acceleration pulse region with particles.

t₁＝200us

2. Upward acceleration motion t 1-t 2

After the particle beam moves horizontally at a uniform speed for t ₁ time, an acceleration pulse is started. The acceleration pulse duration is τ _p and the time of the actual acceleration movement of the particles in the acceleration interval is Δt _n.

The Au ₁ particles are subjected to an upward acceleration a ₁ in the acceleration interval,

The Au ₁ particles are accelerated in the acceleration interval until leaving for a time deltat ₁,

Calculated to obtain

Δt₁＝6.1us

Similarly, the calculated time from the accelerated movement of the Au ₃₀ particles in the acceleration region to the departure is

Δt₃₀＝33.3us

The equal kinetic energy acceleration mode needs to satisfy the conditions: at the end of the acceleration pulse, the Au ₁～Au₃₀ particles have left the acceleration region, the acceleration pulse being greater than the maximum time that the Au ₃₀ particles are accelerated in the acceleration region.

τ_p≥max(Δt₁,Δt₂...Δt₃₀)

Thus selecting the acceleration pulse duration to be

τ_p＝34us

Au ₁～Au₃₀ particles all acquire the same kinetic energy E in the acceleration region,

E＝2000eV

After the acceleration pulse of the acceleration region is over, at this point Au ₃₀ has flown out of the acceleration region, and the upper plate of the acceleration region is held at a voltage of-2000V until Au ₁～Au₃₀ all flies out of the acceleration region and into transition region 1. The voltage diagram of the acceleration pulse is shown in fig. 6.

3. Upward uniform motion t 2-t 3

After the acceleration is finished, the particles acquire the speed in the vertical direction, after the particles fly upwards at a constant speed for Deltat _3-n time, the Au ₁～Au₃₀ particles respectively enter the deceleration areas, the deceleration pulse is started, and the deceleration pulse voltage of the Au ₁～Au₃₀ is respectively applied to the upper parallel plates of the deceleration areas.

Since the voltage variation of the transition zones does not actually affect the particle trajectory, the three transition zones can be regarded as a uniform velocity zone with a height of 1.6m for parameter calculation only by height variation, and the transition zone pulses are shown in fig. 7.

The kinetic energy of the particles in the vertical direction is E,

In fact, q.E.apprxeq.U ₀,

E＝2000eV

Calculated to obtain

4. Upward deceleration movement t3-t4

The duration of the deceleration pulse is Δt _4-n, the pulse duration being related to the time of actual acceleration.

The height of the deceleration zone is 15cm, the height of the acceleration zone is 15cm, the deceleration pulse time Deltat _4-n is the same as the actual acceleration time Deltat _n, and the potential difference of the deceleration zone needs to be achieved

A potential difference in the deceleration zone is obtained,

U₁＝U₀＝10000V

5. Horizontal uniform speed fly-out t4-t5

After the deceleration pulse is finished, the particle beam resumes horizontal uniform motion, the duration is deltat ₅, and all particles entering from the inlet from the time t ₀ to the time t ₁ can fly out from the outlet, and the collection is finished.

The horizontal kinetic energy of the particle beam entering the mass selection section is E ₀, the horizontal velocity of the particle is v _xn,

The time from the particle entering the mass selector at time T ₀ to the end of the deceleration pulse (i.e., the shortest time that Au 1-Au 30 stay in the mass selector) is T _xn

T_xn＝t₁+Δt_n+Δt_3-n+Δt_4-n

In addition, the distance of the gold particle n for preventing the particle beam from being influenced by the side wall malformed electric field

S＝20cm

T _xn together with S determines the overall length of the device

L＝max(T_xn·v_xn)+S＝T_x30·v_x30+S≈9m

Because the length of the deceleration zone is based on the time t ₀ The distance of particle movement determines that the Au _n ⁺ particles coming in at time t ₁ move less than t ₁ time, requiring an additional period of movement out of the deceleration zone.

Δt_5-n＝Δt₁＝200us

The design method of the period T comprises the following steps:

For Au _n ⁺ particles, there is no longer a second deceleration pulse for Δt _5-n after the end of the deceleration pulse, otherwise some particles move downward under the influence of the electric field.

Therefore, the period T of the acceleration pulse and the deceleration pulse needs to satisfy the condition 1:

T≥Δt_5-n＝200us

The period is to satisfy condition 2: is greater than the horizontal uniform velocity entry time t ₁ plus the acceleration pulse time tau _p

T≥Δt₁+τ_p＝450us

Meanwhile, particles in the first period are not influenced by the deceleration pulse of particles in the second period, otherwise, particles with heavy mass in each period are influenced by the deceleration pulse in the next period and cannot be collected.

Thus, the period T needs to satisfy the condition 3: the first period of Au30 particles enters the acceleration region after leaving the transition region 3, while the second period of Au2 enters the acceleration region.

T≥450us

To sum up, the period takes t=450 us.

Theoretical utilization efficiency:

Theoretically, at most, only particles entering from the inlet at time T ₀～t₁ (without considering other losses) can be collected in the time of each period T, and the theoretical utilization efficiency R of the particles is:

l is the device length 9m, L _n is The baffle length of the particle collecting layer, v _xn is/>T is the overall cycle length.

Particles with a length of S cannot be collected due to distorted electric fields on the left and right sides of the acceleration region,The particle moves horizontally at a velocity v _xn.

The passing rate in particle theory is

In fact, the length of the particle trajectory affected by the malformed electric field is not determined, and the average pass rate of the particles is calculated as s=20 cm.

The simulation results are shown in fig. 9, the passing rate is shown in fig. 10, and the theory is basically consistent with the simulation results under the incidence of particles with two continuous periods.

It should be noted that the foregoing merely illustrates the technical idea of the present invention and is not intended to limit the scope of the present invention, and that a person skilled in the art may make several improvements and modifications without departing from the principles of the present invention, which fall within the scope of the claims of the present invention.

Claims (7)

1. The multi-channel mass selector for the cross-polarity correction of the equivalent kinetic energy voltage is arranged in a vacuum cavity and is characterized by comprising parallel plate electrodes, an inlet slit plate, an outlet slit plate and a vertical plate, wherein 1 acceleration zone, 3 transition zones and a plurality of deceleration zones are formed, the parallel plate electrodes on the upper side and the lower side of each zone are arranged in parallel, one side of the acceleration zone is the inlet slit plate, the other side of the deceleration zone is the vertical plate, one side of the deceleration zone is the outlet slit plate, the other side of the deceleration zone is the vertical plate, the two sides of the other zone are the vertical plates, the parallel plate electrodes are perpendicular to and attached to corresponding plates on the left side and the right side, the parallel plate electrodes are externally connected with a high-voltage pulse power supply, one end of the inlet slit plate, which is close to the lower parallel plate electrode in each zone, is provided with an outlet slit, and the areas are electrically insulated;

the acceleration region adjusts pulse voltages of the acceleration region and the transition region according to the selected particle range, so that all the selected particles obtain the same kinetic energy;

the accelerating area consists of an upper parallel plate and a lower parallel plate, the voltage of the upper parallel plate is constant, the accelerating pulse voltage is applied to the lower parallel plate, the electric field direction of the accelerating pulse voltage is vertical upwards, the cluster particles are accelerated upwards to move under a uniform electric field, the speed in the vertical direction is obtained, and the accelerating time is less than the time from the time that the maximum mass particle selected at the time is always accelerated to move in the accelerating area until leaving;

The transition area is used for realizing the transition of the pulse voltage amplitude from the acceleration area to the deceleration area;

The transition pulse voltage is applied to the upper parallel plate, the lower parallel plate, the left parallel plate and the right parallel plate corresponding to the transition zone 2, so that the transition of the pulse voltage amplitude from the voltage amplitude of the acceleration zone to the voltage amplitude of the deceleration zone is realized;

The deceleration zone is to change the vertical velocity of the selected particles to 0, so that the particles fly in the horizontal direction, and the selected particles with the preset mass are obtained from the outlet slit;

in each layer of deceleration zone, deceleration pulse is applied to the upper metal bottom plate of the deceleration zone n, the electric field direction is vertically downward, and the duration of the pulse is that the particles selected by the layer move in the deceleration zone in a deceleration manner until the speed in the vertical direction is 0.

2. The multi-channel mass selector for cross-polarity correction of a peer kinetic voltage of claim 1 wherein the parallel plate electrode, the inlet slit plate, the outlet slit plate and the vertical plate are all aluminum.

3. A multi-channel mass selector for polarity correction of voltage across equivalent kinetic energy according to claim 1, characterized in that the parallel plate electrodes are 7000mm-9000mm in length, 2500mm in width and 3mm in thickness.

4. A multi-channel mass selector for cross-polarity correction of a voltage according to claim 1, wherein the distance between the inner surfaces of the two parallel plate electrodes in the transition zone 2 is 1400mm, and the distance between the inner surfaces of the two parallel plate electrodes in the transition zone 1 is 150mm except 50mm.

5. A multi-channel mass selector for cross-polarity correction of peer kinetic energy voltages as defined in claim 1 wherein said entrance slit plate and exit slit plate each have a slit length of 2000mm and a width of 2mm to 10mm.

6. A multi-channel mass selector for equipotential voltage cross-polarity correction according to claim 1, characterized in that the distance between the entrance slit centerline and the inner surface of the lower parallel plate of the acceleration section 1 is 12mm, and the distance between the exit slit centerline of each layer n from the deceleration section 1 and the inner surface of the lower parallel plate electrode of the deceleration section is 12mm.

7. A multi-channel mass selector for peer to peer kinetic energy voltage cross polarity correction according to claim 1, wherein the selector operates on the principle that:

The time required for charged particles of different masses to fly through a defined path under a constant electric field is related to their mass; this allows the actual flight path of the charged particles between the parallel plate electrodes to be related to their mass under a pulsed electric field with a defined pulse width; n sections of different flight moments are available for all particles; in the time period of t0-t1, the potential difference between the two polar plates is zero, after the cluster particles enter the parallel plate electrode area from the inlet slit, the cluster particles fly parallel to the plane of the electrode, and in the time period of t1-t2, the particles accelerate to move and are divided into two sections: the positive charged clusters will first undergo a lateral acceleration flight perpendicular to the plane of the electrodes, beginning with an acceleration pulse t ₁-t₂₁; in the period of t ₂₁-t₂, the acceleration pulse 1 is ended, the particles keep a fixed speed to fly upwards in an inclined way until Au30 flies out of the acceleration area, and the kinetic energy of all the particles is the same; all particles fly upwards at a constant speed in the time period of t2-t3 until reaching the collecting layer of each particle, the particles start decelerating in the time period of t3-t4 until the vertical speed of the particles is reduced to 0, and fly for a certain time at a constant speed in the time period of t4-t5 until reaching the outlet slit of the layer; since clusters of different masses have different lateral flight accelerations, their lateral flight distances are different in the same flight time, which results in clusters of different masses whose flight paths no longer coincide after time t ₂₁;

the ratio of the t0-t1 time period to the pulse period determines the percentage of clusters of a given mass that can be selected from among the total number of such mass clusters generated by the cluster source, i.e., the maximum pass rate R _max of mass selection; the pass rate is calculated by the following formula:

deltat ₁ is the time length of the T0-T1 time period, and T is the pulse period.