580 research outputs found
Shielding and synchrotron radiation in toroidal waveguide
We develop a new approach to the calculation of the synchrotron radiation in a toroidal vacuum chamber. Using a small parameter ɛ = √ a/R, wherea is the characteristic size of the cross section of the toroid and R is the bending radius, we simplify Maxwell’s equations assuming that the characteristic frequency of the modes ω ∼ c/aɛ, and neglecte terms of higher order in ɛ. For a rectangular cross section of the waveguide, we find an analytical solution of the equations and analyze their asymptotics at very high frequency. We then obtain an equation which gives radiation into each synchronous mode. We demonstrate the flexibility of the new method by calculating the frequencies and the loss factors for the lowest modes in a square and round waveguides. For short bunches of high-energy electrons or positrons, typical for modern accelerators and photon sources, one of the important elements of the beam dynamics is the effect of coherent synchrotron radiation (CSR) of the beam [1]. In vacuum, if the reduced wavelength of the radiation exceeds the bunch length, the beam radiates coherently, and the power of the radiation increases many orders of magnitude relative to the incoherent radiation at the sam
Recommended from our members
Monthly report to LLNL from the Budker INP. Novosibirsk, September, 1992
The experiments on a plasma equilibrium response to externally applied disturbance of the magnetic field of a dipole type have been done on the GDT facility. The disturbance was produced by a pair of the coils installed at the end tank so as it was localized in the expander region. The results were compared with the theoretical predictions based on a hydromagnetic model of plasma equilibrium in the magnetic field treated in a long thin approximation. It was found that the measured displacements of the plasma column from a geometrical axis of the device varies linearly with the current in the disturbing coils at least up to 5cm at the midplane. The data was processed to subtract the displacement measured for zero current that apparently caused by a small disturbance of the magnetic field by soft-iron-made parts of the equipment placed near the device inside the experimental hall and, in part, also by misalignments of the main coils. Theoretically predicted slope of the displacement-field amplitude dependence is to be inversely proportional to a pressure-weighted curvature averaged along the device. The authors believe this allows the use of the data for the measurements of this value. The slopes have been calculated for the GDT parameters under different assumptions on Kp parameter that define an upper limit of integration of the pressure-weighted curvature in the near-end wall region in the expanders
- …