We have studied the linear dispersion relation for Langmuir waves in plasmas of very high density, based on Dirac–Heisenberg–Wigner formalism. The vacuum contribution to physical observables leads ultraviolet divergences, which are removed by a charge renormalization. remaining is small and agreement with previously derived expressions time-dependent polarization. main new feature theory dampin...

There is a great deal of interest in image-guided radiotherapy (IGRT), and to advance the state of IGRT, an integrated linear accelerator-magnetic resonance (linac-MR) system has been proposed. Knowledge of the radiofrequency (RF) emissions near a linac is important for the design of appropriate RF shielding to facilitate the successful integration of these two devices. The frequency spectra of...