Pulsed discharges can generate high power densities and high equivalent electric fields in plasma to emit X-rays,which is closely related to discharge mechanism.In this paper,discharge characteristics and X-ray emissi...Pulsed discharges can generate high power densities and high equivalent electric fields in plasma to emit X-rays,which is closely related to discharge mechanism.In this paper,discharge characteristics and X-ray emission of typical nanosecond-pulse discharges(corona,diffuse,spark or arc)are reviewed.Especially,the diffuse discharges are observed at pulse repetition frequencies up to 1 kHz.Factors influencing the discharge characteristics and X-ray emission are analyzed,such as the gap spacing,parameters of the applied pulse(amplitude,pulse repetition frequency),anode and cathode materials,and curvature radius of cathode.It is concluded that the maximum X-ray intensity is obtained in a diffuse discharge,and the X-ray intensity is affected by the pulse repetition frequency,applied voltage,anode material,and curvature radius of cathode.For example,X-ray intensity increases with the pulse repetition frequency and the atomic numbers of the anode material,but it decrease with the increase of curvature radius.It is also shown that the cathode material has no obvious influence on the X-ray intensity.展开更多
基于闪烁体原理的快离子损失探针(Fast Ion Loss Detector,FILD),可以同时测量损失快离子的能量和pitch-angle的值,是核聚变装置中对高能粒子诊断的重要方式。根据先进实验超导托卡马克(Experimental Advanced Superconducting Tokamak,...基于闪烁体原理的快离子损失探针(Fast Ion Loss Detector,FILD),可以同时测量损失快离子的能量和pitch-angle的值,是核聚变装置中对高能粒子诊断的重要方式。根据先进实验超导托卡马克(Experimental Advanced Superconducting Tokamak,EAST)的发展需求,为了更好地对损失快离子行为进行研究,设计并安装了快离子损失诊断,且探测到在中性束加热条件下产生的损失快离子。同时,探测到在放电中产生的逃逸电子,以及低杂波注入时快电子产生X射线对快离子损失背景信号的影响。并且在H-mode放电时边界扰动也对快离子损失信号产生影响,这些探测到的现象都为不断升级损失诊断系统提供依据。展开更多
Breakdown of atmospheric pressure air gaps with combined design of the cathode at the voltage pulse rise rate equal to 1014V/s has been studied with picoseconds’temporal resolution.Cathode assembly has a structure co...Breakdown of atmospheric pressure air gaps with combined design of the cathode at the voltage pulse rise rate equal to 1014V/s has been studied with picoseconds’temporal resolution.Cathode assembly has a structure consisting of a flat thin foil and a grid of parallel foil thin wires.In the space behind the cathode foil a fast electron flow was recorded.The current value of the fast electron beam recorded behind the cathode is essentially influenced by the anode material.At a grid cathode and flat anode,the spectra of fast electrons generated both in direct(towards the anode)and reverse directions have been reconstructed by the attenuation curves.展开更多
基金Project supported by National NatumA Science Foundation of China（51207154, 51222701, 51211120183）, National Basic Research Program of China（973 Program） （2011 CB209402）, Opening Project of State Key Laboratory of Electrical Insulation and Power Equipment in Xi＇an Jiaotong University（EIPE12204）, Chinese Academy of Sciences Visiting Professorship for Senior Intemational Scientists（2012T1G0021）, Russian Foundation for Basic Research（#12-08-91150-FqbEH_a）.
文摘Pulsed discharges can generate high power densities and high equivalent electric fields in plasma to emit X-rays,which is closely related to discharge mechanism.In this paper,discharge characteristics and X-ray emission of typical nanosecond-pulse discharges(corona,diffuse,spark or arc)are reviewed.Especially,the diffuse discharges are observed at pulse repetition frequencies up to 1 kHz.Factors influencing the discharge characteristics and X-ray emission are analyzed,such as the gap spacing,parameters of the applied pulse(amplitude,pulse repetition frequency),anode and cathode materials,and curvature radius of cathode.It is concluded that the maximum X-ray intensity is obtained in a diffuse discharge,and the X-ray intensity is affected by the pulse repetition frequency,applied voltage,anode material,and curvature radius of cathode.For example,X-ray intensity increases with the pulse repetition frequency and the atomic numbers of the anode material,but it decrease with the increase of curvature radius.It is also shown that the cathode material has no obvious influence on the X-ray intensity.
文摘基于闪烁体原理的快离子损失探针(Fast Ion Loss Detector,FILD),可以同时测量损失快离子的能量和pitch-angle的值,是核聚变装置中对高能粒子诊断的重要方式。根据先进实验超导托卡马克(Experimental Advanced Superconducting Tokamak,EAST)的发展需求,为了更好地对损失快离子行为进行研究,设计并安装了快离子损失诊断,且探测到在中性束加热条件下产生的损失快离子。同时,探测到在放电中产生的逃逸电子,以及低杂波注入时快电子产生X射线对快离子损失背景信号的影响。并且在H-mode放电时边界扰动也对快离子损失信号产生影响,这些探测到的现象都为不断升级损失诊断系统提供依据。
基金Project supported by Russian Foundation for Basic Research(12-08-00081_a,12-08-00105-a)
文摘Breakdown of atmospheric pressure air gaps with combined design of the cathode at the voltage pulse rise rate equal to 1014V/s has been studied with picoseconds’temporal resolution.Cathode assembly has a structure consisting of a flat thin foil and a grid of parallel foil thin wires.In the space behind the cathode foil a fast electron flow was recorded.The current value of the fast electron beam recorded behind the cathode is essentially influenced by the anode material.At a grid cathode and flat anode,the spectra of fast electrons generated both in direct(towards the anode)and reverse directions have been reconstructed by the attenuation curves.
