scholarly journals Space charge limited flow of a thin electron beam confined by a strong magnetic field

2004 ◽  
Vol 11 (10) ◽  
pp. 4559-4563 ◽  
Author(s):  
A. Rokhlenko ◽  
J. L. Lebowitz
Keyword(s):  
Magnetic Field ◽  
Electron Beam ◽  
Space Charge ◽  
Strong Magnetic Field ◽  
Thin Electron ◽  
Space Charge Limited

scholarly journals Low-Energy State Electron Beam in a Uniform Channel

Plasma ◽  
2019 ◽  
Vol 2 (2) ◽  
pp. 222-228 ◽  
Author(s):  
Mikhail Fuks ◽  
Dmitrii Andreev ◽  
Artem Kuskov ◽  
Edl Schamiloglu
Keyword(s):  
Magnetic Field ◽  
Electron Beam ◽  
Space Charge ◽  
Virtual Cathode ◽  
Energy State ◽  
Beam Current ◽  
Low Energy ◽  
Magnetic Mirror ◽  
Limiting Current ◽  
Uniform Channel

In our earlier work, we showed that a low-energy state of an electron beam exists in a nonuniform channel between two virtual cathodes in a magnetron with diffraction output, which consists of three uniform sections with increasing radius. A uniform axial magnetic field fills the interaction space. This led to magnetron operation with >90% efficiency when combined with a magnetic mirror field at the output end. In this present paper, we show that a low-energy state of an electron beam can be realized in a uniform channel in which an increasing magnetic field is used in order to create a magnetic mirror at the output end. We consider two cases, one where the injected beam current slightly exceeds the space-charge-limiting current and the other where the injected beam current greatly exceeds the space-charge-limiting current. On the time scale of relevance to planned experiments (∼30 ns), when the injected current slightly exceeds the space-charge-limiting current a stationary virtual cathode forms and when the injected current greatly exceeds the space-charge-limiting current the virtual cathode oscillates back and forth.

Whistler wave emission by a modulated electron beam injected into a plasma column surrounded by a uniform medium

2007 ◽  
Vol 73 (6) ◽  
pp. 967-980
Author(s):  
C. KRAFFT ◽  
T. M. ZABORONKOVA
Keyword(s):  
Magnetic Field ◽  
Electron Beam ◽  
Plasma Column ◽  
Modulation Frequency ◽  
Whistler Wave ◽  
Wave Radiation ◽  
Physical Conditions ◽  
Beam Modulation ◽  
Uniform Medium ◽  
Thin Electron

AbstractThe efficiency of whistler wave radiation by a density modulated and thin electron beam of finite length injected parallel with respect to the constant ambient magnetic field into a cylindrical plasma column surrounded by a uniform isotropic medium and aligned along the magnetic field is studied. A rigorous analytical derivation of the wave fields excited by the beam in the plasma column is presented. The time-averaged power radiated by the beam at the modulation frequency is determined. In particular, numerical calculations performed for physical conditions relevant to laboratory magnetized discharge plasmas show that, in the presence of a plasma column, the power lost by the modulated beam can be efficiently enhanced owing to resonant Cherenkov excitation of guided whistler modes at the beam modulation frequency.

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