scholarly journals Radiation instability in a split-cavity resonator

2019 ◽  
pp. 22-30
Author(s):  
Illia V. Maroz ◽  
Anatoly A. Rouba
Keyword(s):  
Electromagnetic Field ◽  
Electron Beam ◽  
Space Charge ◽  
Cavity Resonator ◽  
Beam Current ◽  
Variable Component ◽  
Cylindrical Resonator ◽  
Radiation Beam ◽  
Asymmetric System ◽  
System Output

The interaction of an electron beam with the electromagnetic field of a split resonator that consists of a hollow cylindrical resonator and a conducting grid dividing it into coupled sections was considered. In the small-signal approximation, taking into account the space charge of the beam for an asymmetric resonator, the expression for the energy loss by the electron passing through the system was obtained. Within the chosen approximation, it was shown that a resonator with equal length sections provides greater efficiency in the transfer of energy from a charged particles beam to an electromagnetic field in comparison with an asymmetric system configuration. It was found that the interaction of an electron with a space charge in a split resonator leads to the increase of the radiation beam instability with the increase of its density. The effect of current modulation of the electron beam passing through the system was studied. It was shown that the resonator size increase leads to the increase of the amplitude of the beam current variable component at the system output. The increase of the current density of the beam entering the interaction region also leads to the increase of the modulation efficiency. The possibility of increasing the modulated current amplitude in a system with unequal sections was considered.

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.

scholarly journals Generation of Electron and Fast Atom Beams by a Grid Immersed in Plasma

2021 ◽  
Vol 248 ◽  
pp. 04001
Author(s):  
Alexander Metel ◽  
Enver Mustafaev ◽  
Yury Melnik ◽  
Khaled Hamdy
Keyword(s):  
Electron Beam ◽  
Space Charge ◽  
Beam Current ◽  
Secondary Emission ◽  
Electron Beam Current ◽  
Electron Current ◽  
Neutral Atoms ◽  
Atom Beam ◽  
Fast Atom Beam ◽  
Grid Surface

We present a new method of product processing with beams of accelerated electrons and fast neutral atoms, which are generated by an immersed in plasma grid under a high negative voltage of 5 kV. The electrons appear due to secondary emission from the grid surface provoked by its bombardment with ions accelerated from the plasma. At the gas pressure not exceeding 0.1 Pa the ions with energy of 5 keV reach the grid without collisions in the space charge sheaths near its surface and their current in the grid circuit is by 2-3 times lower than the electron current. At higher pressures accelerated ions due to charge exchange collisions in the sheaths turn into fast neutral atoms leaving the sheaths and forming the beams. With the pressure increasing, the electron beam current diminishes and the current of fast atom beam grows.

Cathodoluminescence of SiO2/Si System

2009 ◽  
Vol 156-158 ◽  
pp. 487-492 ◽  
Author(s):  
M.V. Zamoryanskaya
Keyword(s):  
Activation Energy ◽  
Electron Beam ◽  
Rise Time ◽  
Silicon Oxide ◽  
Beam Current ◽  
Electron Beam Current ◽  
Electron Traps ◽  
Definition Of ◽  
Luminescent Centers

In this paper the new method for determination of luminescent centers concentration are discussed. While the possibility of electron traps determination and definition of its activation energy are suggested. The cathodoluminescent (CL) method was used. The determination of luminescent centers concentration in silicon oxide is based on the measurements of dependences of CL intensity on electron beam current. The presence and energy of activation of electron traps were studied by measurement of rise time and decay of luminescent band during the stationary irradiation of silica by electron beam.

Sign in / Sign up

Export Citation Format

Share Document