JACoW is a publisher in Geneva, Switzerland that publishes the proceedings of accelerator conferences held around the world by an international collaboration of editors.
@unpublished{zen:linac2022-th2aa01,
author = {H. Zen},
title = {{High Extraction Efficiency Operation of Oscillator-Type Free Electron Laser Driven by a Normal Conducting Linac}},
booktitle = {Proc. LINAC'22},
language = {english},
intype = {presented at the},
series = {International Linear Accelerator Conference},
number = {31},
venue = {Liverpool, UK},
publisher = {JACoW Publishing, Geneva, Switzerland},
month = {09},
year = {2022},
note = {presented at LINAC'22 in Liverpool, UK, unpublished},
abstract = {{The highest extraction efficiency (9.4%) of a Free Electron Laser (FEL) oscillator has been achieved at the mid-infrared FEL facility of Kyoto University*. The FEL is driven by a normal conducting linac consisting of a thermionic/photocathode RF gun and a traveling wave accelerator tube. The dynamic cavity desynchronization method**,*** was used to achieve the high extraction efficiency with a short macro-pulse duration (7 micro-s). Because of the interaction between the electron beam and FEL electromagnetic field, a maximum electron energy decrease of 16% was observed. An FEL micro-pulse energy of ~100 micro-J with the micro-pulse duration of 150 fs at the wavelength of 11 micro-m was observed. The detailed structure of the FEL micro-pulse was measured using a fringe resolved autocorrelation with a phase retrieval algorithm. As a result, superradiance ringing (or Burnham Chiao ringing), i.e. generation of multiple sub-pulses and 180-degree phase jumps between those sub-pulses, was experimentally observed for the first time in an FEL oscillator.}},
}