| Paper |
Title |
Page |
| WEO2A02 |
Single Shot Longitudinal Bunch Profile Measurements by Temporally Resolved Electro-Optical Detection
|
221 |
| |
- P. J. Phillips, A. MacLeod
UAD, Dundee
- G. Berden, A. F.G. van der Meer
FOM Rijnhuizen, Nieuwegein
- W. A. Gillespie
University of Dundee, Nethergate, Dundee, Scotland
- S. P. Jamison
STFC/DL/ASTeC, Daresbury, Warrington, Cheshire
- E.-A. Knabbe, B. Schmidt, P. Schmüser, B. Steffen
DESY, Hamburg
|
|
| |
For the high-gain operation of a SASE FEL, extremly 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 experiment to probe the time structure of the electric field of single sub 200fs e-bunches. In this technique, the field-induced birefringence in an electro-optic crystal is encoded on a chirped ps 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 30 fs laser pulse using a second-harmonic crystal (temporal decoding). In the temporal decoding measurements an electro-optic signal of 180 fs FWHM was observed, and is close to the limit due to the material properties of the particular electro-optic crystal used. The measured electro-optical signals are compared to bunch shapes simultaneously measured with a transversly deflecting cavity.
|
|
| WEPB03 |
Femtosecond Yb-Doped Fiber Laser System at 1 um of Wavelength with 100-nm Bandwidth and Variable Pulse Structure for Accelerator Diagnostics
|
235 |
| |
- A. Winter, B. Steffen
DESY, Hamburg
- F. O. Ilday
Bilkent University, Bilkent, Ankara
|
|
| |
Laser-based diagnostic systems play an increasingly important role in accelerator diagnostics in, for instance, measurements of the electron bunch length. To date, the laser system of choice for electro-optic experiments has been the Ti:Sa laser. These offer nJ pulse energies at fixed repetition rate between 50-100 MHz, which is not well suited to the bunch structure of facilities such as FLASH (several hundred pulses with 1 MHz spacing at 1-5 Hz repetition rate).The limited robustness, stability and operability of Ti:Sa systems make them less than an ideal candidate for a continuously running measurement system requiring minimal maintenance. Fiber lasers represent a promising alternative, since gating and subsequent amplification is simple and of low cost, hence a pulse pattern corresponding exactly to the linac bunch pattern can be generated. Furthermore, these lasers offer superior robustness at a fraction of the cost of a Ti:Sa laser and have been shown to work without maintenance for several months and longer. Here, we present an ytterbium-doped fiber laser system with 80 nm bandwidth and multi-nJ pulse energy with adjustable bunch pattern for use in electro-optic experiments.
|
|