@inproceedings{oai:repo.qst.go.jp:00054956,
 author = {全炳俊 and 紀井俊輝 and 大垣英明 and 羽島, 良一 and 羽島 良一},
 book = {第15回日本加速器学会年会論文集},
 month = {Jan},
 note = {An oscillator-type mid-infrared Free Electron Laser (FEL) named as KU-FEL has been developed at the Institute of
Advanced Energy, Kyoto University. The extraction efficiency is one of the key parameter of FEL and determines its
performance. In this study, the extraction efficiency of KU-FEL was measured by measuring the energy distribution of
electron beam with and without FEL lasing at the downstream of the undulator. The measured extraction efficiency was
around 5% at the highest power condition of the relative optical cavity length. This value is the highest extraction
efficiency observed in an oscillator-type FEL driven by a normal conducting linac. The macro-pulse duration and bunch
charge of the linac at KU-FEL are relatively smaller than other facilities. The reason why KU-FEL could achieve such
high extraction efficiency was discussed and concluded as the “Dynamic Cavity Desynchronization” in a macro-pulse.},
 title = {京都大学中赤外自由電子レーザの引き出し効率測定},
 year = {2019}
}