FLASH free-electron laser single-shot temporal diagnostic: Terahertz-field-driven streaking

Abstract

The commissioning of a terahertz-field-driven streak camera installed at the free-electron laser (FEL) FLASH at DESY in Hamburg, being able to deliver photon pulse duration as well as arrival time information with 10fs resolution for each single XUV FEL pulse, is reported. Pulse durations between 300fs and <15fs have been measured for different FLASH FEL settings. A comparison between the XUV pulse arrival time and the FEL electron bunch arrival time measured at the FLASH linac section exhibits a correlation width of 20fs r.m.s., thus demonstrating the excellent operation stability of FLASH. In addition, the terahertz-streaking setup was operated simultaneously to an alternative method to determine the FEL pulse duration based on spectral analysis. FLASH pulse duration derived from simple spectral analysis is in good agreement with that from terahertz-streaking measurement.The installation and commissioning of a pulse length diagnostic setup at FLASH based on terahertz streaking is reported.