CN107247196A - A kind of multi purpose space charge-measuring system and measuring method - Google Patents

Abstract

A multifunctional space charge measurement system and measurement method, the measurement system includes an upper electrode for measurement, a lower electrode for measurement, a pulse generating device connected to the pulse input end of the upper electrode for measurement, and a DC high voltage connected to the high voltage input end of the upper electrode for measurement source, the sample is set between the upper electrode for measurement and the lower electrode for measurement; the lower electrode for measurement includes a metal casing, and the upper cover plate of the lower electrode, which is arranged on the top of the metal casing and contacts the lower surface of the sample, is arranged in the metal casing and connected with the lower electrode. The thin-film sensor attached to the lower surface of the upper cover, the metal shielding shell covered outside the thin-film sensor, the low-noise amplifier connected to the thin-film sensor, the panel connector embedded in the metal shell, and the low-noise amplifier connected to the panel connector; An oscilloscope connected with a matching line and a panel joint; the invention also discloses a measurement method; the invention not only has the function of conventional space charge measurement, but also has the rules of charge injection and dissipation for plate-shaped samples of different thicknesses in a simulated space vacuum high-energy electronic environment And the function of online measurement of charge and electric field distribution.

Description

A multifunctional space charge measurement system and measurement method

technical field

The invention belongs to the technical field of space charge measurement in dielectric materials using an electroacoustic pulse method, and in particular relates to a multifunctional space charge measurement system and a measurement method.

Background technique

As a key component of electrical and electronic devices, insulating media have electrical and aging properties that directly affect the reliability and life of equipment. Studies have shown that space charge is an important factor causing electrical aging of polymers, and the space charge distribution of materials can directly reflect the degree of electrical aging of polymers, structural damage, trap density and their distribution. The most serious impact of the space environment on the reliability of spacecraft is the electrons of various energies. The accumulation of electrons inside or on the surface of the dielectric material will form a high electrostatic potential, and cause pulse discharges that seriously affect the normal operation of the electronic system. The device breaks down or burns out. It is of great significance to study the space charge distribution of dielectric materials under the irradiation of high-energy electrons to ensure the operational reliability and life of spacecraft.

After more than 20 years of development, the pulse electroacoustic method (PEA) has been widely used to study the space charge distribution in solid insulating media. However, the conventional space charge measurement system based on the electroacoustic pulse method cannot be used for online measurement of space charge in the case of electron beam irradiation in a simulated space environment, and the applicable sample size range is extremely narrow, only less than 0.5 mm thick.

Contents of the invention

In order to overcome the deficiencies in the above-mentioned prior art, the object of the present invention is to provide a multifunctional space charge measurement system and measurement method. The system not only has the conventional space charge measurement function, but also extends the measurement range to samples with a thickness of 5mm and below. , and has the function of online measurement of the charge injection and dissipation rules, charge and electric field distribution of plate-shaped material samples with different thicknesses under the simulated space vacuum high-energy electron environment.

To achieve the above object, the present invention adopts the following technical solutions:

A multifunctional space charge measurement system, comprising a measuring upper electrode 1, a measuring lower electrode 12, a pulse generating device 2 with adjustable pulse parameters connected to the measuring upper electrode 1 pulse input end, and a measuring upper electrode 1 high-voltage input end Connected DC high-voltage source 3, the sample is arranged between the measurement upper electrode 1 and the measurement lower electrode 12; the measurement lower electrode 12 includes a metal shell 8, a lower electrode that is arranged on the top of the metal shell 8 and contacts the lower surface of the sample The upper cover plate 4 is arranged in the metal shell 8 and is closely attached to the lower surface of the upper cover plate 4 of the lower electrode. The low noise amplifier 7, the panel connector 9 embedded in the metal shell 8, there is a signal transmission port and a power inlet in the panel connector 9, which are respectively used to transmit the signal amplified by the low noise amplifier 7 and supply power to the low noise amplifier 7 , the low noise amplifier 7 is connected to the panel joint 9; the integration circuit matching line 10 connected to the signal transmission port of the panel joint 9 is connected to the oscilloscope 11 at the other end of the integration circuit matching line 10 .

The measuring upper electrode 1 is the electrode in the applicant's independent invention patent (patent number: ZL 2011 1 0359855.X).

The pulse generating device 2 can adjust the amplitude and pulse width of the input pulse signal according to the thickness of the sample. At the same time, the film sensor 5 adjusts the thickness of the film to adapt to the measurement of samples of different thicknesses, so that the entire measurement system can realize the measurement of plates of different thicknesses. sample material; the adjustable range of the pulse amplitude of the pulse generating device 2 is 0-3600V, the adjustable range of the pulse width is 5ns-150ns; the adjustable range of the film thickness of the film sensor 5 is 5μm-100μm; The sample thickness range is 0.1mm ~ 5mm.

The system conducts conventional measurement with DC high voltage applied in general atmospheric environment, and the applied voltage range is 1kV~50kV; at the same time, it can also measure the space charge distribution of the sample in real time under electron irradiation environment, and the electron energy range is 10keV~10MeV, and The system can perform experimental measurements in both vertical and horizontal radiation cases.

The upper measuring electrode 1 and the lower measuring electrode 12 are fixedly connected by screws and nuts.

The integration circuit matching line 10 is mainly composed of capacitors and resistors, and is used to eliminate waveform distortion.

The measurement method of the above-mentioned multifunctional space charge measurement system uses the pulse electroacoustic method as the basic principle. When applying a DC high voltage for conventional measurement in a general atmospheric environment, the source of the measurement charge is the pressurized DC high voltage source 3; according to the measurement The thickness of the sample is used to select the pulse parameters and the thickness of the sensor; the pressure of the DC high-voltage source 3 causes the sample to be injected with a certain polarity of charge, and the pulse applied by the pulse generator 2 will generate when it passes through the internal charge position of the sample. Acoustic pulse waves of corresponding polarity; the acoustic pulse waves are transmitted through the sample and the upper cover plate 4 of the lower electrode, and then are received by the film sensor 5 and converted into electrical signals, and then the output electrical signal waveform is amplified by the low-noise amplifier 7 and integrated The waveform of the circuit matching line 10 is corrected, and finally received by the oscilloscope 11, and then the obtained waveform is calibrated and denoised to the signal data, and finally the charge distribution and electric field intensity distribution of the sample are obtained;

The charge accumulation principle of the sample under the electron irradiation environment is the direct injection of electrons. Under the electron irradiation environment, the measurement of the system does not need to be connected to a DC voltage, so the DC high voltage source 3 is not needed, and the upper electrode 1 is used to directly receive the charge. Electron injection, the electrons stay inside the sample to directly form space charge, and then use the pulse sent by the pulse generator 2 to excite the sound wave signal related to the charge, the sound wave signal is transmitted through the sample and the upper cover plate 4 of the lower electrode The film sensor 5 receives and converts it into a corresponding electrical signal; then the electrical signal is amplified by the low-noise amplifier 7, then the waveform is corrected by the matching line 10 of the integrating circuit, and finally acquired by the oscilloscope 11, and then the obtained waveform is calibrated and compared to the signal data After denoising processing, the charge distribution and electric field intensity distribution of the sample are finally obtained.

Compared with the prior art, the present invention has the following advantages:

1, the advantages of the multifunctional space charge measurement system of the present invention compared with the common space charge measurement system are as follows: (1) the system can apply DC high voltage in general atmospheric environment to carry out routine measurement; (2) the thickness of the measurement sample is changed from 0.1 mm can be expanded to 5mm; (3) the space charge can be measured online under the environment of electron irradiation. The adjustment range of the external DC voltage is 1kV～50kV, and the variation range of the electron radiation energy is 10keV～10MeV.

2. The pulse generating device 2 can continuously adjust the amplitude and pulse width of the input pulse signal according to the thickness of the tested sample, and the film sensor 5 can adjust the thickness of the sensor according to the thickness of the tested sample to obtain the measurement required for measuring different plate samples. Sensitivity and Resolution. The continuously adjustable range of pulse amplitude is 0~3600V, the continuous adjustable range of pulse width is 5ns~150ns; the adjustable range of piezoelectric sensor thickness is 5μm~100μm; the measurable sample thickness range is 0.1mm~5mm.

3. The measurement electrodes of the measurement system are mechanically fixed in a fixed direction, which can meet the experimental requirements of forward or lateral measurement, and has wider applicability.

4. The electrode in the patent No. ZL 2011 1 0359855.X is used as the upper electrode 1 for measurement, which can monitor and observe the charge injection and dissipation of the sample in real time, and provides convenience for the in-situ online measurement of the space charge of the material. The electrode does not need to apply DC high voltage when measuring high-energy electron radiation. The through hole penetrating from the surface of the upper electrode to the bottom surface of the upper electrode is a channel for injecting high-energy electrons into the plate sample.

5. The entire measurement system, including the upper and lower electrodes and the insulating material and jacket in the connection, are all made of radiation-resistant polymer materials, which can not only protect the measurement system, but also will not affect the measurement due to degassing of organic materials.

Description of drawings

Fig. 1 is a connection schematic diagram of the multifunctional space charge measurement system of the present invention.

Fig. 2 is a schematic diagram of the measurement results of the multifunctional space charge measurement system of the present invention, wherein: Fig. 2 (a) is a conventional measurement effect diagram in a general atmospheric environment, and Fig. 2 (b) is a measurement effect diagram in an electron irradiation environment.

detailed description

The working principle of the present invention will be described in more detail below in conjunction with the accompanying drawings.

As shown in Fig. 1, a kind of multifunctional space charge measuring system of the present invention comprises measuring upper electrode 1, measuring lower electrode 12, the pulse generating device 2 of the adjustable pulse parameter connected with measuring upper electrode 1 pulse input end, and Measure the DC high-voltage source 3 connected to the high-voltage access end of the upper electrode 1, and the sample is arranged between the upper electrode 1 and the lower electrode 12; the lower electrode 12 includes a metal casing 8, which is arranged on the top of the metal casing 8 and connected The lower electrode upper cover plate 4 that is in contact with the lower surface of the sample, the thin film sensor 5 that can change the thickness that is arranged in the metal shell 8 and is close to the lower surface of the lower electrode upper cover plate 4, and the metal shielding shell that is covered on the outer surface of the thin film sensor 5 6. The low-noise amplifier 7 connected to the thin-film sensor 5, the panel joint 9 embedded in the metal shell 8, and the panel joint 9 has a signal transmission port and a power inlet, which are respectively used for outgoing low-noise amplifier 7 amplified Signal and power supply to the low noise amplifier 7, the low noise amplifier 7 is connected to the panel joint 9; the integration circuit matching line 10 connected to the signal transmission port of the panel joint 9 is connected to the oscilloscope 11 at the other end of the integration circuit matching line 10.

The measurement method of a multifunctional space charge measurement system of the present invention is as follows: the pulse electroacoustic method is used as the basic principle, and when a DC high voltage is applied in a general atmospheric environment for routine measurement, the source of the measured charge is the DC high voltage source 3 that applies pressure. The pulse parameters and sensor thickness are selected according to the thickness of the measured sample. The pressure applied by the DC high-voltage source 3 causes charges of a certain polarity to be injected into the sample, and the pulse applied by the pulse source 2 will generate an acoustic pulse wave of the corresponding polarity when passing through the charge position inside the sample. After the acoustic pulse wave passes through the sample and the upper cover plate 4 of the lower electrode, it is received by the film sensor 5 and converted into an electrical signal, and then the output electrical signal waveform is amplified by the low noise amplifier 7, and the waveform is corrected by the matching line 10 of the integrating circuit. Finally, it is received by the oscilloscope 11, and then the obtained waveform is subjected to calibration and denoising processing on the signal data, and finally the charge distribution and electric field intensity distribution of the sample are obtained. The conventional measurement effect in the general atmospheric environment is shown in Figure 2(a) in Figure 2. It can be seen from the figure that the interface charge peaks at both ends of the waveform are positive and negative opposite polarity charge peaks. Since the pulse and sensor parameters can be adjusted according to the sample conditions, the sensitivity of the measurement is guaranteed, so the characteristics of the charge peak in the waveform are obvious, and there is no serious waveform "overshoot" phenomenon under the action of the circuit matching line.

The charge accumulation principle of the sample under the electron irradiation environment is the direct injection of electrons. Under the electron irradiation environment, the measurement of the system does not need to be connected to a DC voltage, so a DC high voltage source is not required. The electrode 1 directly accepts the injection of electrons, and the electrons stay inside the material to directly form a space charge, and then use the pulse sent by the pulse generator 2 to excite the acoustic wave signal related to the charge. The transmission is accepted by the film sensor 5 and converted into corresponding electrical signals. Then the electrical signal is amplified by the low-noise amplifier 7, and then the waveform is corrected by the matching line 10 of the integrating circuit, and finally acquired by the oscilloscope 11, and then the obtained waveform is subjected to calibration and denoising processing on the signal data, and finally the charge distribution and distribution of the sample are obtained. Electric field strength distribution. The measurement effect is shown in Figure 2(b) in Figure 2, which is the waveform obtained by online measurement in a horizontal radiation environment. It can be seen from the figure that, unlike the conventional measurement results in general atmospheric environments, the waveform obtained by online The interface charge peaks at both ends are positive charge peaks of the same polarity. The negative charge peak corresponding to the space charge generated by the electron irradiation in the sample is very obvious, which is the result of choosing the appropriate pulse and film sensor parameters.

The present invention has applied the specific embodiment to set forth the principle of the present invention and the implementation mode, and the description of the above embodiment is only used to help understand the method of the present invention and its core idea; meanwhile, for those of ordinary skill in the art, according to the present invention Thoughts, corresponding changes in the specific implementation and application scope all belong to the protection scope of the present invention.

Claims (6)

1. a kind of multi purpose space charge-measuring system, it is characterised in that：Including measurement Top electrode (1), bottom electrode (12) is measured, The pulse generating unit (2) for the adjustable pulse parameter being connected with measurement Top electrode (1) pulse incoming end, with measurement Top electrode (1) The DC high-voltage source (3) of high pressure incoming end connection, sample is arranged between measurement Top electrode (1) and measurement bottom electrode (12)；It is described Measuring bottom electrode (12) includes metal shell (8), is arranged on the lower electricity contacted at the top of metal shell (8) and with the lower surface of sample Pole upper cover plate (4), be arranged in metal shell (8) and with bottom electrode upper cover plate (4) lower surface is close to changes the thin of thickness Film sensors (5), cover on the outside metal shielding (6) of thin film sensor (5), the low noise being connected with thin film sensor (5) Amplifier (7), being embedded in the panel connector (9) on metal shell (8), panel connector (9) has a signal transmission mouth and one Individual plant-grid connection mouthful, is respectively used to spread out of the signal of low-noise amplifier (7) amplification and gives low-noise amplifier (7) power supply, low Noise amplifier (7) is connected with panel connector (9)；The integrating circuit matched line being connected with the signal transmission mouth of panel connector (9) (10), it is connected to the oscillograph (11) of integrating circuit matched line (10) other end.

2. multi purpose space charge-measuring system according to claim 1, it is characterised in that：The pulse generating unit (2) amplitude and pulsewidth of input pulse signal can be adjusted according to sample thickness, while thin film sensor (5) is by adjusting film Thickness to adapt to the measurement of different-thickness sample so that whole measuring system is realized to be entered to the plate tensile sample material of different-thickness Row measurement；The pulse amplitude adjustable extent of the pulse generating unit (2) is 0~3600V, the adjustable range of pulsewidth for 5ns~ 150ns；The film thickness adjustable range of thin film sensor (5) is 5 μm~100 μm；Measurable sample thickness scope is 0.1mm ~5mm.

3. multi purpose space charge-measuring system according to claim 1, it is characterised in that：The system is in general atmosphere ring External dc high pressure carries out general measure under border, and application voltage range is 1kV~50kV；Simultaneously also can be in electron irradiation environment The distribution of space charge situation of the lower sample of measurement in real time, electron energy scope is 10keV~10MeV, and the system is in vertical spoke Penetrate and horizontal radiation in the case of can all carry out experiment measurement.

4. multi purpose space charge-measuring system according to claim 1, it is characterised in that：The measurement Top electrode (1) It is fixedly connected with measurement bottom electrode (12) by screw rod with nut.

5. multi purpose space charge-measuring system according to claim 1, it is characterised in that：The integrating circuit matched line (10) mainly it is made up of electric capacity and resistance, the distortion for eliminating waveform.

6. the measuring method of multi purpose space charge-measuring system described in claim 1, it is characterised in that：Made with pulse radio-acoustic method For general principle, when applying high direct voltage progress general measure under normal atmospheric environment, the source of measurement electric charge is pressure DC high-voltage source (3)；The selection of pulse parameter and sensor thickness is carried out according to the thickness of measurement sample；DC high-voltage source (3) Pressure to be injected into the electric charge of certain polarity in sample, the pulse that pulse generating unit (2) is applied is by sample The ping ripple of corresponding polarity can be produced during portion's Charge sites；Ping ripple be transferred through sample and bottom electrode upper cover plate (4) it Received afterwards by thin film sensor (5) and be changed into electric signal, the electric signal waveform exported afterwards is put by low-noise amplifier (7) Greatly, and integrated Circuit Matching line (10) carry out waveform modification, finally by oscillograph (11) receive, afterwards by obtained waveform pair Signal data is demarcated and denoising, the final distribution of charges and electric-field intensity distribution for obtaining sample；

The charge collection principle of sample under electron irradiation environment is directly injected into for electronics, the system under electron irradiation environment Measurement need not access DC voltage, so do not need DC high-voltage source (3), electricity is directly received using Top electrode (1) is measured Son injection, electrons stay directly forms space charge inside sample, and the pulse then sent using pulse generating unit (2) is swashed The acoustic signals related to electric charge are sent, acoustic signals are transmitted with sample and bottom electrode upper cover plate (4) for medium, by film Sensor (5) receives and is converted into corresponding electric signal；Subsequent electric signal amplifies by low-noise amplifier (7), then through product Parallel circuit matched line (10) carries out waveform modification, is finally obtained by oscillograph (11), afterwards by obtained waveform to signal data Demarcated and denoising, the final distribution of charges and electric-field intensity distribution for obtaining sample.