Cross-Correlation of THz Pulses from the Electron Storage Ring BESSY II

Abstract

Coherent synchrotron radiation from an electron storage ring is observed in the THz spectral range when the bunch length is shortened down to the sub-mm-range. With increasing stored current, the bunch becomes longitudinally unstable and modulates the THz emission in the time domain. These micro-instabilities are investigated at the electron storage ring BESSY II by means of cross-correlation of the THz fields from successive bunches. The investigations allow deriving the longitudinal length scale of the micro bunch fluctuations and show that it grows faster than the current-dependent bunch length. Our findings will help to set the limits for the possible time resolution for pump-probe experiments achieved with coherent THz synchrotron radiation from a storage ring.

Terahertz as a Frontier Area for Science and Technology

“…Coherent synchrotron radiation from an electron storage ring is observed in the THz spectral range when the bunch length is shortened to the sub-mm-range. Schade and co-workers, in their contribution [32], showed that increasing the stored current in the ring causes the bunch to become longitudinally unstable and modulates the THz emission in the time domain. Their results set the limits for the possible time resolution of pump-probe experiments with coherent THz synchrotron radiation from a storage ring.…”