The effect of air pressure(12.5,25,50,and 100 kPa)on the gen eration of runaway electron beams in a non-uniform electric field when applying voltage pulses(~35 kV)with a rise time of?200 ns has been studied.The result...The effect of air pressure(12.5,25,50,and 100 kPa)on the gen eration of runaway electron beams in a non-uniform electric field when applying voltage pulses(~35 kV)with a rise time of?200 ns has been studied.The results show that the discharge has various stages:streamer,diffuse,and spark.Initially,a wide streamer develops in the gap and a diffuse discharge is formed.A spark is formed u 100 ns after the breakdown.The current pulse of a supershort avalanche electron beam(SAEB)was measured with a collector at various pressures of air.Experiments show that there are two modes of generation of run away electrons.At an air pressure of 25-100 kPa,a single SAEB current pulse with a full width at half-maximum(FWHM)of 120-140 ps is observed.At the air pressure of 12.5 kPa,two current pulses of the electron beam are observed.FWHM of the first and second current pulses are ul40ps and u300 ps,respectively.The current pulse amplitude of the second electron beam is higher than that of the first one,but the electron energy is less.展开更多
Diffuse and volume discharges are currently used widely in various fields.This work compares the properties of diffuse and volume discharges,as well as considers the conditions for their formation at high pressures.Th...Diffuse and volume discharges are currently used widely in various fields.This work compares the properties of diffuse and volume discharges,as well as considers the conditions for their formation at high pressures.The main attention is paid to a diffuse discharge(DD).It has been shown that the ignition of a diffuse discharges is preceded by the development of a wide streamers.In the case of a volume discharge,the streamers usually have a small diameter and an ionisation waves emerging from it passes into the spark leader with subsequent discharge constriction.There are images and emission spectra of diffuse discharges in air and nitrogen in the paper.It has been confirmed that a diffuse discharges initiated by a nanosecond voltage pulse in a point-to-plane gaps has a uniform effect on the surface of a flat electrode.It was found that thin tracks of luminous particles are observed against the background of the DD plasma glow.They are asso-ciated with sputtering of the pointed electrode material due to the large field enhance-ment on the macro-and microinhomogeneities.展开更多
文摘The effect of air pressure(12.5,25,50,and 100 kPa)on the gen eration of runaway electron beams in a non-uniform electric field when applying voltage pulses(~35 kV)with a rise time of?200 ns has been studied.The results show that the discharge has various stages:streamer,diffuse,and spark.Initially,a wide streamer develops in the gap and a diffuse discharge is formed.A spark is formed u 100 ns after the breakdown.The current pulse of a supershort avalanche electron beam(SAEB)was measured with a collector at various pressures of air.Experiments show that there are two modes of generation of run away electrons.At an air pressure of 25-100 kPa,a single SAEB current pulse with a full width at half-maximum(FWHM)of 120-140 ps is observed.At the air pressure of 12.5 kPa,two current pulses of the electron beam are observed.FWHM of the first and second current pulses are ul40ps and u300 ps,respectively.The current pulse amplitude of the second electron beam is higher than that of the first one,but the electron energy is less.
基金Ministry of Education and Science of the Russian Federation,Grant/Award Number:FWRM-2021-0014National Natural Science Foundation of China,Grant/Award Number:52261145695。
文摘Diffuse and volume discharges are currently used widely in various fields.This work compares the properties of diffuse and volume discharges,as well as considers the conditions for their formation at high pressures.The main attention is paid to a diffuse discharge(DD).It has been shown that the ignition of a diffuse discharges is preceded by the development of a wide streamers.In the case of a volume discharge,the streamers usually have a small diameter and an ionisation waves emerging from it passes into the spark leader with subsequent discharge constriction.There are images and emission spectra of diffuse discharges in air and nitrogen in the paper.It has been confirmed that a diffuse discharges initiated by a nanosecond voltage pulse in a point-to-plane gaps has a uniform effect on the surface of a flat electrode.It was found that thin tracks of luminous particles are observed against the background of the DD plasma glow.They are asso-ciated with sputtering of the pointed electrode material due to the large field enhance-ment on the macro-and microinhomogeneities.
