An apparatus and method for measuring the spatial distribution of free molecular currents

Abstract

This invention discloses an apparatus and method for measuring the spatial distribution of free molecular streams. The apparatus includes a scanner, a time measuring device, and a signal receiving device. The scanner includes a rotating mechanism and sampling holes, with a plurality of sampling holes arranged in a circle on the rotating mechanism. The center of the uppermost sampling hole of the rotating mechanism is on the same horizontal line as the center of the signal receiving device. The time measuring device includes a timer, which is connected to both the scanner and the signal receiving device to measure the flight time of the free molecular stream from the sampling holes to the signal receiving device. The signal receiving device includes an ionization chamber and an actuation mechanism, with the ionization chamber mounted on the actuation mechanism and its center point coinciding with that of the actuation mechanism. This apparatus uses a three-dimensional dynamic scanning method to obtain the spatial distribution of the free molecular stream, deriving its spatial molecular distribution morphology and obtaining distribution information of the molecular stream.

Description

Technical Field

[0001] This invention belongs to the field of gas spatial distribution measurement technology, specifically relating to a device for measuring the spatial distribution of free molecular flow. This device can be installed in a vacuum environment to obtain the spatial distribution of molecules in a free molecular flow state. Background Technology

[0002] Gas flow in space can be broadly categorized into three modes: continuous flow, transitional flow, and free molecular flow. Gases exhibit different characteristics in these three flow domains and show different distributions even within the same domain. The distribution is particularly complex under molecular flow, and understanding the spatial and temporal distribution of molecules is crucial for research on particle interaction mechanisms, vacuum conduction effects, and surface science. For free molecular flow, current technologies typically employ instruments such as pressure gauges and mass spectrometers to measure pressure, composition, density, and temperature, achieving macroscopic information acquisition. However, these methods cannot provide a microscopic, three-dimensional characterization of molecular distribution, nor can they reveal its spatial dynamic distribution. Summary of the Invention

[0003] The purpose of this invention is to provide a device for measuring the spatial distribution of free molecular flow. This device uses a three-dimensional dynamic scanning method to obtain the spatial distribution of free molecular flow, thereby obtaining its molecular distribution morphology in space and acquiring distribution information of the molecular flow.

[0004] To achieve the above objectives, the present invention adopts the following technical solution:

[0005] An apparatus for measuring the spatial distribution of free molecular currents, the apparatus comprising a scanner, a time measuring device, and a signal receiving device;

[0006] The scanner includes a rotating mechanism and sampling holes. The rotating mechanism has several sampling holes arranged in a circle. The center of the sampling hole at the top of the rotating mechanism is on the same horizontal line as the center of the signal receiving device.

[0007] The time measuring device includes a timer, which is connected to a scanner and a signal receiving device to measure the flight time of the free molecular stream from the sampling orifice to the signal receiving device.

[0008] The signal receiving device includes an ionization chamber and an actuation mechanism. The ionization chamber is mounted on the actuation mechanism, and the center point of the ionization chamber coincides with that of the actuation mechanism.

[0009] The ionization chamber includes an ionization source, a counter, a signal conditioning module, and a power supply. The ionization source is used to ionize the gas molecules entering the ionization chamber to form ions. The counter counts the ions, and finally the signal conditioning module outputs the gas molecule abundance.

[0010] Preferably, the rotating mechanism is disc-shaped.

[0011] Preferably, a three-dimensional turntable is provided on the actuation mechanism, so that the actuation mechanism can move in three-dimensional space.

[0012] The present invention also provides a method for measuring the spatial distribution of free molecular currents, the method comprising the following steps:

[0013] The scanner rotates repeatedly through the central rotating mechanism. The free molecule flow is injected through the sampling hole and enters the signal receiving device, where it is sampled and used as the starting point for the timing of the time measuring device.

[0014] The time measuring device obtains the time it takes for the gas to travel from the scanner to the time measuring device. The gas velocity can be obtained by dividing the distance between the two by the flight time. The start signal is obtained from the uppermost sampling port, and the end signal is obtained from the incoming flow signal received by the signal receiving device.

[0015] The signal receiving device performs a three-dimensional moving scan, moving the device horizontally and vertically back and forth, allowing molecules at different positions to enter the ionization chamber. In the ionization chamber, the incoming gas is ionized, and the ion abundance at different positions is obtained after counting. This ion abundance is proportional to the gas abundance, thereby obtaining the distribution of the gas quantity in the spatial plane, obtaining the quantity information of gas at different positions, and obtaining the flight speed of gas at different spatial positions.

[0016] Compared with the prior art, the present invention has the following technical effects:

[0017] This invention can perform microscopic three-dimensional characterization of molecular distribution and obtain its spatial microscopic dynamic distribution.

[0018] This invention can obtain the three-dimensional microstructure of free molecular flow.

[0019] This invention can obtain the flight speed of molecules at different positions in a free molecular flow. Attached Figure Description

[0020] Figure 1 This is a schematic diagram of the device for measuring the spatial distribution of free molecular current according to the present invention;

[0021] Figure 2 This is a schematic diagram of the signal receiving device of the present invention;

[0022] Figure 3 This is a schematic diagram of the connection of the device for measuring the spatial distribution of free molecular current according to the present invention;

[0023] Figure 4 This is a schematic diagram of the ionization chamber of the present invention;

[0024] Figure 5 This is a schematic diagram of the principle of the present invention;

[0025] Figure 6 This is a schematic diagram of the spatial distribution of free molecular flow tested in this invention.

[0026] Reference numerals: 1. Rotating mechanism; 2. Time measuring device; 3. Signal receiving device; 4. Sampling hole. Detailed Implementation

[0027] The present invention will now be described in further detail with reference to the accompanying drawings and specific embodiments.

[0028] Example 1

[0029] like Figure 1 As shown, an apparatus for measuring the spatial distribution of free molecular currents includes a scanner 1, a time measuring device 2, and a signal receiving device 3.

[0030] The scanner includes a disc-shaped rotating mechanism 1 and a sampling hole 4. The rotating mechanism is provided with a plurality of sampling holes in a circular pattern. The center of the sampling hole at the uppermost end of the rotating mechanism is on the same horizontal line as the center of the signal receiving device.

[0031] like Figure 3 As shown, the time measuring device includes a timer, which is connected to a scanner and a signal receiving device to measure the flight time of the free molecular stream from the sampling orifice to the signal receiving device.

[0032] like Figure 2 As shown, the signal receiving device includes an ionization chamber and an actuation mechanism. The ionization chamber is mounted on the actuation mechanism, and the center point of the ionization chamber coincides with that of the actuation mechanism.

[0033] like Figure 4 As shown, the ionization chamber includes an ionization source, a counter, a signal conditioning module, and a power supply. The ionization source ionizes gas molecules entering the ionization chamber, forming ions. The counter counts the ions, and the result is output through the signal conditioning module to represent the gas molecule abundance. The power supply provides power to the counter, and can also provide power to the ionization source and the signal conditioning module. Figure 4 (Not shown in the image).

[0034] This invention comprises three parts: a scanner, a time measuring device, and a signal receiving device, as shown in the schematic diagram below. Figure 4 As shown:

[0035] The scanner consists of a rotating mechanism and a sampling aperture. The center of the uppermost sampling aperture is on the same horizontal line as the center of the signal receiving device. The scanner rotates repeatedly through the central rotating mechanism, and the free molecular flow is injected through the sampling aperture into the signal receiving device, where it is sampled. This sample serves as the starting point for the timing of the time measurement device.

[0036] The time measuring device consists of a timer, which obtains the time it takes for the gas to travel from the scanner to the time measuring device. The gas velocity is obtained by dividing the distance between the two by the flight time. The start signal is obtained from the uppermost sampling port, and the stop signal is obtained from the incoming flow signal received by the signal receiving device.

[0037] The signal receiving device consists of an ionization chamber and an actuation mechanism. The ionization chamber is mounted on the actuation mechanism, with the center point of the ionization chamber coinciding with that of the actuation mechanism. The actuation mechanism can achieve three-dimensional scanning. A three-dimensional turntable mounted on it can move the signal receiving device horizontally, vertically, forward, and backward, allowing molecules at different locations to enter the ionization chamber. In the ionization chamber, the incoming gas is ionized, and the ion abundance at different locations is obtained by counting the ions. This ion abundance is proportional to the gas abundance, thus obtaining the distribution of gas quantity in a spatial plane.

[0038] like Figure 5 As shown, through the above three devices, the gas passes through the scanner, time measuring device, and signal receiving device in sequence. Finally, the spatial distribution of the gas is obtained on the signal receiving device, the quantity information of the gas at different locations is obtained, and the flight speed of the gas at different spatial locations is obtained.

[0039] The scanner of this invention samples the incoming flow, allowing the gas to enter a time measurement device and a signal receiving device. The time measurement device measures the total time it takes for the gas to travel from the scanner to the signal receiving device. The signal receiving device ionizes the gas and measures its abundance. The spatial distribution of the free molecular flow is ultimately obtained, as shown in the figure. Figure 6 As shown. Figure 5 The diagram illustrates the spatial distribution of free molecular flow. X represents the vertical direction, Y represents the horizontal direction, and Z represents the other direction perpendicular to XY. The Z direction is fixed, and the actuator moves within the XY plane to scan the X and Y directions respectively, thereby achieving XY direction scanning reception and obtaining the abundance at different locations.

[0040] The various components in this invention, such as the rotating mechanism, timer, counter, ionization chamber, signal conditioning module, and power supply, can all be conventional components in the art and are readily available for purchase.

[0041] All aspects not described in detail in this invention can be covered using conventional technical knowledge in the field.

[0042] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and are not intended to limit it. Although the present invention has been described in detail with reference to the embodiments, those skilled in the art should understand that modifications or equivalent substitutions to the technical solutions of the present invention do not depart from the spirit and scope of the technical solutions of the present invention, and all such modifications or substitutions should be covered within the scope of the claims of the present invention.

Claims

1. A device for measuring the spatial distribution of free molecular current, characterized in that, The device includes a scanner, a time measuring device, and a signal receiving device; The scanner includes a rotating mechanism and sampling holes. The rotating mechanism has several sampling holes arranged in a circle. The center of the sampling hole at the top of the rotating mechanism is on the same horizontal line as the center of the signal receiving device. The time measuring device includes a timer, which is connected to a scanner and a signal receiving device to measure the flight time of the free molecular stream from the sampling orifice to the signal receiving device. The signal receiving device includes an ionization chamber and an actuation mechanism. The ionization chamber is mounted on the actuation mechanism, and the center point of the ionization chamber coincides with that of the actuation mechanism. The ionization chamber includes an ionization source, a counter, a signal conditioning module, and a power supply. The ionization source is used to ionize gas molecules entering the ionization chamber to form ions. The counter counts the ions, and finally the signal conditioning module outputs the gas molecule abundance. The above-mentioned device allows the gas to pass sequentially through a scanner, a time measuring device, and a signal receiving device. Finally, the spatial distribution of the gas is obtained on the signal receiving device, which provides information on the quantity of gas at different locations and the flight speed of the gas at different spatial locations.

2. The apparatus for measuring the spatial distribution of free molecular current according to claim 1, characterized in that, The rotating mechanism is disc-shaped.

3. The apparatus for measuring the spatial distribution of free molecular currents according to claim 1, characterized in that, The actuation mechanism is equipped with a three-dimensional turntable, which enables the actuation mechanism to move in three-dimensional space.

4. A method for measuring the spatial distribution of free molecular currents based on the apparatus of claim 1, the method comprising the following steps: The scanner rotates repeatedly through the central rotating mechanism. The free molecule flow is injected through the sampling hole and enters the signal receiving device, where it is sampled and used as the starting point for the timing of the time measuring device. The time measuring device obtains the time it takes for the gas to travel from the scanner to the time measuring device. The gas velocity can be obtained by dividing the distance between the two by the flight time. The start signal is obtained from the uppermost sampling port, and the end signal is obtained from the incoming flow signal received by the signal receiving device. The signal receiving device performs a three-dimensional moving scan, moving the device horizontally and vertically back and forth, allowing molecules at different positions to enter the ionization chamber. In the ionization chamber, the incoming gas is ionized, and the ion abundance at different positions is obtained after counting. This ion abundance is proportional to the gas abundance, thereby obtaining the distribution of the gas quantity in the spatial plane, obtaining the quantity information of gas at different positions, and obtaining the flight speed of gas at different spatial positions.

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