Two techniques are applied to diagnose characteristic parameters of plasma created by hypervelocity impact, such as electron temperature and electron density. The first technique is a sweep Langmuir probe （SLP）, whi...Two techniques are applied to diagnose characteristic parameters of plasma created by hypervelocity impact, such as electron temperature and electron density. The first technique is a sweep Langmuir probe （SLP）, which is a new apparatus based on a dual channel circuit that can compensate for stray capacitance and obtain a good synchronicity, so that electrostatic turbulence with a good temporal resolution can be acquired. The second technique is a triple Langmuir probe （TLP）, which is an electrostatic triple Langmuir probe diagnostic system, in which no voltage and frequency sweep is required. This technique allows to measure electron temperature, electron density as a function of time. Moreover, the triple Langmuir probe diagnostic system allows the direct display of electron temperature and semidirect display of electron density by an appropriate display system, the system permits us to eliminate almost all data processing procedures. SLP and TLP were applied to obtain fluctuations of the characteristic parameters of plasma generated by hypervelocity impact. As an example of their application to time-dependent plasma measure- ment, the electron temperature and electron density of plasmas were acquired in hypervelocity impact experiments. Characteristic parameters of plasma generated by hypervelocity impact were compared by the two kinds of diagnostic techniques mentioned above.展开更多
A method for the fast measurement of electron temperature and density with temporal resolution in transient plasma has been implemented by Langmuir probe. The diagnostic system consists of a single Lang- muir probe dr...A method for the fast measurement of electron temperature and density with temporal resolution in transient plasma has been implemented by Langmuir probe. The diagnostic system consists of a single Lang- muir probe driven by a high frequency sinusoidal voltage. The current and voltage spectrum on the probe were detected synchronously by an oscilloscope with sampling rate being at least 5 times higher than the frequency of sweep voltage. The system has been used to diagnose the transient plasma generated by hypervelocity-impact of LY12 aluminum projectile into LY12 aluminum target.展开更多
A fast-sweep Langmuir probe （FSLP） diagnostic system was designed and applied to obtain the electron temperature fluctuations of a transient plasma. The diagnostic system consists of a single Langmuir probe driven b...A fast-sweep Langmuir probe （FSLP） diagnostic system was designed and applied to obtain the electron temperature fluctuations of a transient plasma. The diagnostic system consists of a single Langmuir probe driven by a high frequency sinusoidal voltage. The current-voltage I- V characteristics can be recorded by sweeping the voltage and measuring the current with an appropriate circuit. This new instrument is based on a dual channel circuit that compensates for stray capacitance. The current and voltage spectra were acquired from the probe synchronously by a digital oscilloscope. The aim of this work was to apply the FSLP diagnostic system to a time- dependent plasma generated by a hypervelocity impact between the LY12 Aluminum projectile and LY12 Aluminum target.展开更多
基金supported by National Natural Science Foundation of China(No.10972145)
文摘Two techniques are applied to diagnose characteristic parameters of plasma created by hypervelocity impact, such as electron temperature and electron density. The first technique is a sweep Langmuir probe （SLP）, which is a new apparatus based on a dual channel circuit that can compensate for stray capacitance and obtain a good synchronicity, so that electrostatic turbulence with a good temporal resolution can be acquired. The second technique is a triple Langmuir probe （TLP）, which is an electrostatic triple Langmuir probe diagnostic system, in which no voltage and frequency sweep is required. This technique allows to measure electron temperature, electron density as a function of time. Moreover, the triple Langmuir probe diagnostic system allows the direct display of electron temperature and semidirect display of electron density by an appropriate display system, the system permits us to eliminate almost all data processing procedures. SLP and TLP were applied to obtain fluctuations of the characteristic parameters of plasma generated by hypervelocity impact. As an example of their application to time-dependent plasma measure- ment, the electron temperature and electron density of plasmas were acquired in hypervelocity impact experiments. Characteristic parameters of plasma generated by hypervelocity impact were compared by the two kinds of diagnostic techniques mentioned above.
文摘A method for the fast measurement of electron temperature and density with temporal resolution in transient plasma has been implemented by Langmuir probe. The diagnostic system consists of a single Lang- muir probe driven by a high frequency sinusoidal voltage. The current and voltage spectrum on the probe were detected synchronously by an oscilloscope with sampling rate being at least 5 times higher than the frequency of sweep voltage. The system has been used to diagnose the transient plasma generated by hypervelocity-impact of LY12 aluminum projectile into LY12 aluminum target.
基金National Natural Science Foundation of China(No.10772028)
文摘A fast-sweep Langmuir probe （FSLP） diagnostic system was designed and applied to obtain the electron temperature fluctuations of a transient plasma. The diagnostic system consists of a single Langmuir probe driven by a high frequency sinusoidal voltage. The current-voltage I- V characteristics can be recorded by sweeping the voltage and measuring the current with an appropriate circuit. This new instrument is based on a dual channel circuit that compensates for stray capacitance. The current and voltage spectra were acquired from the probe synchronously by a digital oscilloscope. The aim of this work was to apply the FSLP diagnostic system to a time- dependent plasma generated by a hypervelocity impact between the LY12 Aluminum projectile and LY12 Aluminum target.
