For the high gain operation of a SASE FEL, extremely short electron bunches are essential to generate sufficiently high peak currents. At the superconducting linac of FLASH at DESY, we have installed an electro- optic measurement system to probe the time structure of the electric field of single ~100 fs electron bunches. In this technique, the field induced birefringence in an electro-optic crystal is encoded on a chirped picosecond laser pulse. The longitudinal electric field profile of the electron bunch is then obtained from the encoded optical pulse by a single shot cross correlation with a 35 fs laser pulse using a second harmonic crystal (temporal decoding). An electro-optical signal exhibiting a feature with 118 fs FWHM was observed, and this is close to the limit of resolution due to the material properties of the particular electro-optic crystal used. The measured electro-optic signals are compared to bunch shapes simultaneously measured with a transverse deflecting cavity.
|Title of host publication||Proceedings of DIPAC 2007|
|Editors||Ivan Andrian, Volker R. W. Schaa|
|Number of pages||3|
|Publication status||Published - 31 Oct 2008|
|Event||8th European Workshop on Beam Diagnostics and Instrumentation for Particle Accelerators - NH Laguna Palace, Venice, Italy|
Duration: 20 May 2007 → 23 May 2007
Conference number: 8
|Workshop||8th European Workshop on Beam Diagnostics and Instrumentation for Particle Accelerators|
|Abbreviated title||DIPAC 2007|
|Period||20/05/07 → 23/05/07|
Phillips, P. J., Gillespie, W. A., Steffen, B., Knabbe, E. A., Schmidt, B., Schmüser, P., ... MacLeod, A. M. (2008). Single shot longitudinal bunch profile measurements by temporally resolved electro-optical detection. In I. Andrian, & V. R. W. Schaa (Eds.), Proceedings of DIPAC 2007 (pp. 221-223). DIPAC.