Dynamics of virtual cathode oscillation analyzed by impedance changes in high-power diodes

2007 ◽  
Vol 102 (12) ◽  
pp. 123309 ◽  
Author(s):  
Limin Li ◽  
Tao Men ◽  
Lie Liu ◽  
Jianchun Wen
Keyword(s):  
High Power ◽  
Virtual Cathode ◽  
Power Diodes ◽  
Virtual Cathode Oscillation

High Power Microwave Generation by Double-Anode Virtual Cathode Oscillator

2019 ◽  
Vol 139 (10) ◽  
pp. 421-427
Author(s):  
Kazuki Nagao ◽  
Wataru Takatsu ◽  
Pham Van Thuan ◽  
Taichi Sugai ◽  
Weihua Jiang
Keyword(s):  
High Power ◽  
Virtual Cathode ◽  
High Power Microwave ◽  
Microwave Generation ◽  
Power Microwave

Hybrid simulation of electrode plasmas in high-power diodes

2009 ◽  
Vol 16 (12) ◽  
pp. 123102 ◽  
Author(s):  
Dale R. Welch ◽  
David V. Rose ◽  
Nichelle Bruner ◽  
Robert E. Clark ◽  
Bryan V. Oliver ◽  
...  
Keyword(s):  
High Power ◽  
Hybrid Simulation ◽  
Power Diodes

Enhancing the power of high power microwaves by using zone plate and investigations for the position of virtual cathode inside the drift tube

2018 ◽  
Vol 25 (10) ◽  
pp. 103113 ◽  
Author(s):  
Sohail Mumtaz ◽  
Jun Sup Lim ◽  
Bhagirath Ghimire ◽  
Suk Woo Lee ◽  
Jin Joo Choi ◽  
...  
Keyword(s):  
High Power ◽  
Drift Tube ◽  
Virtual Cathode ◽  
Zone Plate ◽  
High Power Microwaves

scholarly journals Time evolution of the two-dimensional expansion velocity distributions of the cathode plasma in pulsed high-power diodes

2013 ◽  
Vol 31 (1) ◽  
pp. 129-134 ◽  
Author(s):  
Jie Yang ◽  
Ting Shu ◽  
Yuwei Fan
Keyword(s):  
High Power ◽  
Cathode Surface ◽  
Transverse Velocity ◽  
Longitudinal Velocity ◽  
Expansion Velocity ◽  
Two Dimensional ◽  
Plasma Expansion ◽  
Cathode Plasma ◽  
Power Diodes ◽  
Diode Current

AbstractA combination of electrical and optical diagnostics has been used to investigate the time evolution of the two-dimensional expansion velocity distributions of the cathode plasma in pulsed high-power diodes. The perveance model based on the Child-Langmuir law was used to calculate the expansion velocity of the diode plasmas from voltage and current profiles. Additionally, a four-channel high speed framing camera was used to observe the formation and subsequent movement of the cathode plasma. More accurate and valuable information about the dynamics of the cathode plasma was also acquired by utilizing the digital image processing methods. Results from the experiments and theoretical analysis were compared. In this paper, the experiments have been performed using a high-voltage pulse generator with 200 kV output voltage and 110 ns pulse duration. Current densities up to 440 A/cm2were produced. The observation of the cathode plasma expansion in transverse direction indicated that the diode current was cathode-limited in the current rising stage (the first 60 ns of the current pulse). The perveance model should be modified taking in account the time dependent expanding plasma surface (i.e., not the whole cathode surface) for this period. The velocity in the direction parallel to the cathode surface (transverse velocity) was much larger than that in the direction perpendicular to the cathode surface (longitudinal velocity), and further, it dropped from 90 cm/μs to nearly 20 cm/μs rapidly. It was shown that, during the current flattop stage, the plasma filled out all the surface of cathode and the diode current was space-charge-limited. The values of the transverse velocity and longitudinal velocity were nearly the same and decreased relatively slowly. The satisfactory coincidence of experimental and calculated (both were in the range of 6–8 cm/μs) values of the cathode plasma expansion velocities was obtained.

Influence of anode-cathode gap distance on output characteristics of high-power microwave from coaxial virtual cathode oscillator

2005 ◽  
Vol 33 (4) ◽  
pp. 1353-1357 ◽  
Author(s):  
Kew Yong Sung ◽  
Wook Jeon ◽  
Yoon Jung ◽  
Jeong Eun Lim ◽  
H.S. Uhm ◽  
...  
Keyword(s):  
High Power ◽  
Virtual Cathode ◽  
High Power Microwave ◽  
Output Characteristics ◽  
Power Microwave

Numerical simulation of high-power virtual-cathode reflex triode driven by repetitive short pulse electron gun

1996 ◽  
Vol 24 (3) ◽  
pp. 1015-1022 ◽  
Author(s):  
I.G. Yovchev ◽  
I.P. Spassovsky ◽  
N.A. Nikolov ◽  
D.P. Dimitrov ◽  
G. Messina ◽  
...  
Keyword(s):  
Numerical Simulation ◽  
High Power ◽  
Virtual Cathode ◽  
Short Pulse ◽  
Electron Gun ◽  
Pulse Electron
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