Observation of Microbunching Instabilities using THz Detector at NSLS-II

Weixing Cheng, Belkacem Bacha, G. Lawrence Carr, Olander, Johan (Ed.), Schaa, Volker RW (Ed.), Shea, Thomas (Ed.), Jansson, Andreas (Ed.)
Microbunching instabilities have been observed in several light sources with high single bunch current stored. The instability is typically associated with threshold beam currents. Energy spread and bunch length are increasing above the thresholds. Recently, a terahertz (THz) detector was installed at the cell 22 infrared (IR) beamline at NSLS-II storage ring to study the micro-bunch instabilities. The IR beamline has wide aperture allowing long-wavelength synchrotron radiation or microwave
more » ... on or microwave signal propagate to the end station, where the detector was installed. The detector output signal has been analyzed using oscilloscope, spectrum analyzer and FFT real-time spectrum analyzer. Clear sidebands appear as single bunch current increases and the sidebands tend to shift/jump. We present measurement results of the THz detector at different nominal bunch lengths and ID gaps.
doi:10.18429/jacow-ibic2019-wepp038 fatcat:c2jhqi56d5efheco2vsob47y5e