Increasing the transverse mode coupling instability threshold by RF quadrupole

On Transverse Mode Coupling Instability in VLHC

Transverse Mode Coupling Instability in the Sps: Headtail Simulations and Moses Calculations

Since 2003, single bunches of protons with high intensity (~ 1.2 10 protons) and low longitudinal emittance (~ 0.2 eVs) have been observed to suffer from heavy losses in less than one synchrotron period after injection at 26 GeV/c in the CERN Super Proton Synchrotron (SPS) when the vertical chromaticity is corrected (ξy ~ 0). Understanding the mechanisms underlying this instability is crucial t...

Transverse-mode coupling in a Kerr medium.

We analyze non-linear transverse mode coupling in a Kerr medium placed in an optical cavity and its influence on bistability and different kinds of quantum noise reduction. Even for an input beam which is perfectly matched to a cavity mode, the non-linear coupling produces an excess noise in the fluctuations of the output beam. Intensity squeezing seems to be particularly robust with respect to...

Transverse mode coupling in an optical resonator.

Small-angle scattering due to mirror surface roughness is shown to couple the optical modes and deform the transmission spectra in a frequency-degenerate optical cavity. A simple model based on a random scattering matrix clearly visualizes the mixing and avoided crossings between multiple transverse modes. These effects are visible only in the frequency-domain spectra; cavity ringdown experimen...

Increasing mode instability thresholds of fiber amplifiers by gain saturation.

We show by numerical modeling that saturation of the population inversion reduces the stimulated thermal Rayleigh gain relative to the laser gain in large mode area fiber amplifiers. We show how to exploit this effect to raise mode instability thresholds by a substantial factor. We also demonstrate that when suppression of stimulated Brillouin scattering and the population saturation effect are...