CN201237603Y

CN201237603Y - Particulate speedometer

Info

Publication number: CN201237603Y
Application number: CNU200820109241XU
Authority: CN
Inventors: 李宏伟; 黄建国; 韩建伟; 蔡明辉; 李小银
Original assignee: National Space Science Center of CAS
Current assignee: National Space Science Center of CAS
Priority date: 2008-07-15
Filing date: 2008-07-15
Publication date: 2009-05-13
Anticipated expiration: 2018-07-15

Abstract

The utility model discloses a particle velocity measuring device, comprising a signal acquisition unit, a power supply, a sampling resistance, a voltage division resistance, a wire mesh and a target, wherein, the wire mesh is positioned between the target and an external particle launcher, and the wire mesh is close to the target but does not contact the target; the power supply is connected to the wire mesh through the sample resistance and the partial pressure resistance; the signal acquisition unit is connected to the external particle launcher and is also connected with the sampling resistance for acquiring the signals generated from particles on the sampling resistance when passing through the wire mesh. The utility model has higher measurement accuracy of the time-of-flight of the particles, thereby making the measurement accuracy of the velocity-of-flight of the particles higher; the online measurement can be realized, and the impact experiment substantially can not be affected during measuring and the requirements of ultra-high-velocity particle impact experiments can be better met. Through the collection of plasma formed by the impact of the particles, the utility model has the advantages of short collecting time, great instantaneous current, strong signal amplitude and high signal-to-noise ratio.

Description

A kind of particle speed measurement mechanism

Technical field

The utility model relates to hypervelocity particle speed measurement mechanism, and particularly a kind of hypervelocity impact that utilizes forms the device that plasma effect is measured particle speed.

Background technology

In the particle collision experiment, often need accurately to measure the flying speed of particulate, at thousand meter per seconds (km/s) magnitude or this high speed particle more than magnitude, the accurate measurement of flying speed also is not easy to realize for flying speed.

In the prior art, exist some to be used to measure the relevant apparatus of high rate particle speed, as publication number is in the Chinese patent " a kind of forward scattering laser velocimeter device " of CN2812008, disclose a kind of device that utilizes scattering laser to measure the particulate flying speed, in this device, lay laser illuminator in a specific location, when flying over this laser illuminator, high speed particle can produce scattering laser, by can knowing the time of arrival of particulate, and then extrapolate the speed of particulate to the measurement of this scattering laser.But this device also exists certain defective, for example, because the weak output signal of scattering laser, to the requirement height of signal Processing, makes the composition relative complex of this device, thereby makes cost height, the reliability of device relatively poor.

In the prior art, also exist the principle of utilizing piezoelectricity to test the speed is carried out velocity survey to high speed particle method.The shockwave signals that these methods produce when clashing into the rigidity object that is positioned at specified distance by the collection high speed particle usually obtains the time of arrival of particulate, extrapolates the speed of particulate then.These methods also exist certain defective, as, just can't collect shockwave signals when particle collision during to flexible article or liquid, also just can't measure the time of arrival of particulate and calculate the speed of particulate.In addition, the signal that the particle collision piezoelectric produces has long oscillation period, so piezoelectricity tests the speed and be difficult to differentiate time of arrival from very near bump signal, and the resolution of entire method is lower.

In addition, also the film of useful sandwich structure is as sensor probe, add suitable bias voltage on the film both sides, obtain the time that particulate arrives film, the hypervelocity particle speed method of testing of utilizing time-of-flight method that particle speed is measured again by collecting the plasma that forms when the hypervelocity particle collision passes film.But this method requires the size of particulate will be much larger than the size of film, and when particle size and film dimensions during quite or less than film dimensions, measuring process is can be to the particle speed influence very big even can make and after particulate passes film in the measuring process fragmentation takes place.

Summary of the invention

The purpose of this utility model is the defective that the application scenario is restricted or resolution is lower that overcomes existing particulate flying speed measurement mechanism, thereby a kind of particle speed measurement mechanism with high-resolution is provided.

To achieve these goals, the utility model provides a kind of particle speed measurement mechanism, comprises signal gathering unit, power supply, sample resistance, divider resistance, wire netting and target; Wherein,

Described wire netting is between described target and outside particulate emitter, and described wire netting is near described target but do not contact; Described power supply is connected to described wire netting by described sample resistance and described divider resistance; Described signal gathering unit is connected to outside particulate emitter, also is connected the signal that is produced on described sample resistance when particulate passes described wire netting to gather with described sample resistance.

In the technique scheme, also comprise support, described wire netting is installed in to be realized on the described support fixing.

In the technique scheme, described power supply adopts dc bias power, and described dc bias power is that described wire netting adds bias voltage.

In the technique scheme, the distance between described wire netting and the described target is between 1-5mm.

In the technique scheme, the signal that described signal gathering unit is gathered on described sample resistance comprises voltage or electric current.

In the technique scheme, described signal gathering unit adopts oscillograph to gather voltage on described sample resistance.

In the technique scheme, described oscillograph writes down launch time when the particulate emitter emission particulate of described outside, also writes down the time that described particulate passes described wire netting.

Compared with prior art, the beneficial effects of the utility model are:

1, owing to the time of hypervelocity particle collision formation plasma and wire netting collection plasma is all short especially, generally can be less than microsecond (us), therefore the utility model is higher to the measuring accuracy of particulate flight time, thereby makes to the precision of particulate flying speed measurement also higher;

2, the utility model can be realized on-line measurement, and measuring process can not influence striking experiment substantially, can be good at satisfying hypervelocity particle collision experimental requirements;

3, the utility model can not be subjected to the influence of particulate itself when high speed particle is measured, and range of application is wider;

4, the utility model is by collecting the plasma that particle collision forms, and acquisition time is short, and momentary current is big, and signal amplitude is strong, the signal to noise ratio (S/N ratio) height;

5, the utility model is implemented easily, and technology is simple, the reliability height, and cost is low.

Description of drawings

Below, describe embodiments of the invention in conjunction with the accompanying drawings in detail, wherein:

Fig. 1 is the utility model structural drawing in one embodiment.

The drawing explanation

1---oscillograph 2---dc bias power 3---sample resistance

4---divider resistance 5---support 6---particulates

7---particle movement path 8---wire netting 9---targets

Embodiment

Below in conjunction with the drawings and specific embodiments, the utility model is described further.

Provided an embodiment of particle speed measurement mechanism of the present utility model in Fig. 1, in this embodiment, the particle speed measurement mechanism comprises oscillograph 1, dc bias power 2, sample resistance 3, divider resistance 4, support 5, wire netting 8 and target 9.Wherein, wire netting 8 is installed on the support 5, and wire netting 8 is before target 9, and near target 9 but do not contact with target 9, distance between the two remains between the 1-5mm; Dc bias power 2 is connected on the wire netting 8 by sample resistance 3 and divider resistance 4; Oscillograph 1 is connected to the two ends of sample resistance 3; The outside device that is used to launch particulate is connected with oscillograph 1, make this device when launching particulate 6, can send simultaneously a signal to oscillograph 1 to write down the zero-time of particle movement.

Wire netting 8 among the present invention should adopt the less tinsel of diameter, and the through hole between the tinsel should be big as much as possible, makes to test the speed when experiment carrying out particulate, and particulate can not strike on the wire netting 8, to influence finishing of striking experiment as far as possible.In addition, wire netting 8 has the shape of rule.Homogeneity with near the electric field assurance wire netting.

Dc bias power 2 is used to wire netting 8 to add bias voltage, is used for producing electric field near the wire netting and guaranteeing that near the electric field the wire netting is enough strong, thereby can collects the plasma that the particulate high-speed impact forms.The distance that the size of the bias voltage that is added and wire netting 8 and target are 9 is relevant, and distance is near more, and bias voltage is more little, and for example, when the distance between wire netting 8 and the target 9 during in the 2mm left and right sides, the bias voltage size of being added is about 150v.

Oscillograph 1 is triggered in the particulate emission, and it is used to write down the time of particle collision target 9, thereby obtains the flight time of particulate.In the present embodiment, adopt the flight time of oscillograph 1 record particulate, but those of ordinary skill in the art should understand, the device that is used to write down the particulate flying speed is not limited to oscillograph, can adopt other devices with identity function to replace oscillographs in other embodiments of the invention.

When adopting device shown in Figure 1 that the particulate flying speed is measured, triggering oscillograph 1 when outside high speed particle emitter is launched particulate starts working, particulate along path 7 behind flight certain distance S, high-speed impact is placed on the target 9 of wire netting 8 back, and forms plasma in the moment of bump., therefore can collect the plasma that high-speed impact forms because thereby dc bias power 2 is added with suitable voltage and has produced corresponding electric field on wire netting 8.Because the acquisition time of plasma is very short, can form a bigger momentary current so be added with in the circuit of bias voltage, make the two ends of sample resistance 3 form certain instantaneous voltage.The oscillograph 1 that sample resistance 3 is measured just can record a burst signal, and this pulse signal moment corresponding is exactly the moment of particle collision target.Can obtain the run duration t of particulate according to the x time of moment of particle collision target and particulate.Because aforesaid particulate flying distance S is easy to measure, and therefore, just can access the flying speed v (v=S/t) of high speed particle.

The plasma that the utility model produces when collecting high speed particle rammer surface, come conducting to be in the circuit of off state originally, and plasma was collected in very short time, circuit disconnects again afterwards, in the loop, will form a current/voltage pulse signal that pulsewidth is very little like this, obtain the time signal that particulate arrives body surface by this pulse signal, realized measurement the particle movement time.Measured mean particle dia scope is 10um-1000um in the present embodiment, and the particle speed scope is 3km/s-20km/s.

In fact, those of ordinary skills also should be understood that if do not adopt potential pulse, also can adopt conducting that the method for series current pick-up unit in the loop comes testing circuit whether, and then judge the moment of particle collision target.Those of ordinary skills combine particle speed measurement mechanism described in the present embodiment with prior art, can obtain adopting the method for current detecting to come the particle speed measurement mechanism of testing circuit fully, therefore, carry out repeat specification no longer herein.

It should be noted last that above embodiment is only unrestricted in order to the explanation the technical solution of the utility model.Although the utility model is had been described in detail with reference to embodiment, those of ordinary skill in the art is to be understood that, the technical solution of the utility model is made amendment or is equal to replacement, the spirit and scope that do not break away from technical solutions of the utility model, it all should be encompassed in the middle of the claim scope of the present utility model.

Claims

1, a kind of particle speed measurement mechanism is characterized in that, comprises signal gathering unit, power supply (2), sample resistance (3), divider resistance (4), wire netting (8) and target (9); Wherein,

Described wire netting (8) is positioned between described target (9) and the outside particulate emitter, and described wire netting (8) is near described target (9) but do not contact; Described power supply (2) is connected to described wire netting (8) by described sample resistance (3) and described divider resistance (4); Described signal gathering unit is connected to outside particulate emitter, also is connected the signal that is produced on described sample resistance (3) when particulate passes described wire netting (8) to gather with described sample resistance (3).

2, particle speed measurement mechanism according to claim 1 is characterized in that, also comprises support (5), and described wire netting (8) is installed in described support (5) and upward realizes fixing.

3, particle speed measurement mechanism according to claim 1 and 2 is characterized in that, described power supply (2) adopts dc bias power, and described dc bias power is that described wire netting (8) adds bias voltage.

4, particle speed measurement mechanism according to claim 1 and 2 is characterized in that, the distance between described wire netting (8) and the described target (9) is between 1-5mm.

5, particle speed measurement mechanism according to claim 1 and 2 is characterized in that, the signal that described signal gathering unit is gathered on described sample resistance (3) comprises voltage or electric current.

6, particle speed measurement mechanism according to claim 5 is characterized in that, described signal gathering unit adopts oscillograph to go up at described sample resistance (3) and gathers voltage.

7, particle speed measurement mechanism according to claim 6 is characterized in that, described oscillograph writes down launch time when the particulate emitter emission particulate of described outside, also writes down the time that described particulate passes described wire netting (8).