1. Physics 777 Plasma Physics and Magnetohydrodynamics (MHD) Instructor: Gregory Fleishman Lecture 5. Microscopic Emission Processes in the Plasma 07 October 2008

2. Plan of the Lecture Vavilov-Cherenkov radiation Bremsstrahlung Diffusive radiations Magnetobremsstrahlung Transition radiation

3. Section 1. Vavilov-Cherenkov radiation (N.P. 1958) For simplicity:

4. Section 2. Bremsstrahlung

6. Coherent Bremsstrahlung

7. Section 3. Diffusive radiations Consider first the radiation in the presence of random magnetic field: Diffusive Synchrotron Radiation (DSR)

9. For power-law spectrum of random magnetic field we obtain:

10. Spectral asymptotes

11. Diffusive Radiation in Langmuir Waves (DRL) If

14. Section 4. Magnetobremsstrahlung

15. Asymptotic behavior

16. General case Cyclotron Emission

17. Section 5. Transition Radiation

18. Resonant Transition Radiation

19. Section 6. Homework Homework from Lecture 4. Written report topic (WRT) # 1. Assume stochastic acceleration at the loop top with a power-law spectrum of magnetic turbulence. Calculate the DSR spectrum from electrons with different non-relativistic energies. WRT # 2. Assume a power-law spectrum for Langmuir wave ensemble and some number (Ax10 33 ) of relativistic electrons with the Lorenz factor 10. Calculate the DRL spectrum. WRT # 3. Calculate synchrotron emission from warm and hot components of the interstellar medium. Calculate and plot these contribution together for different filling factors. WRT # 4. Assume sinusoidal oscillations of the transverse magnetic field component. Calculate modulation amplitude (or power), phase, and degree of polarization as a function of frequency. WRT # 5. Assume that the particle trapping at the Masuda source is provided by scattering of the electrons by magnetic inhomogeneities with a power-law spectrum. Calculate the DSR produced by the electrons generating the above- the-loop-top hard X-ray emission (i.e., take the electron spectrum from the corresponding papers). For all WRT: outline the introduction for the written report. Use Latex, e.g., ApJ style (preferable).