Electron-beam instability in left-handed media
Yury P Bliokh1, Sergey Savel'ev, Franco Nori
1Advanced Science Institute, The Institute of Physical and Chemical Research (RIKEN), Wako-shi, Saitama 351-0198, Japan.
Physical Review Letters
|July 23, 2008
Summary
Two electron beams passing through left-handed media (LHM) can become unstable, generating electromagnetic waves and chaotic radiation. This instability, unique to LHM, can be controlled by beam current or spacing.
Area of Science:
- Physics
- Electromagnetism
- Plasma Physics
Background:
- Left-handed materials (LHM) exhibit unique electromagnetic properties not found in natural media.
- Electron beam interactions with materials can lead to complex phenomena like instabilities and radiation.
- Cherenkov radiation typically occurs when charged particles exceed the phase velocity of light in a medium.
Purpose of the Study:
- To investigate the potential instability arising from two electron beams traversing a left-handed media slab.
- To analyze the characteristics of the electromagnetic radiation generated by this instability.
- To explore methods for controlling the radiation intensity and spectrum.
Main Methods:
- Theoretical prediction of instability development for two electron beams in LHM.
- Simulation of the self-modulation process and electromagnetic wave generation.
- Analysis of the resulting radiation spectrum to identify dynamical chaos.
Main Results:
- A novel instability is predicted for two electron beams in LHM, stemming from backward Cherenkov radiation.
- The instability causes self-modulation of the beams and emission of electromagnetic waves.
- Simulated radiation spectra reveal distinct lines superimposed on a continuous band, indicative of dynamical chaos.
- Observed radiation intensity and spectrum are controllable via beam current and inter-beam distance.
Conclusions:
- Left-handed media can support unique beam-plasma instabilities driven by backward Cherenkov radiation.
- The interaction leads to chaotic dynamics and controllable electromagnetic wave emission.
- This phenomenon offers potential for novel tunable radiation sources and understanding complex beam-matter interactions.
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