| Paper |
Title |
Page |
| TUPC114 |
Results from the Optical Replica Experiments in FLASH
|
1332 |
| |
- V. G. Ziemann, G. Angelova
UU/ISV, Uppsala
- J. Boedewadt, S. Khan, A. Winter
Uni HH, Hamburg
- M. Hamberg, M. Larsson, P. M. Salen, P. van der Meulen
FYSIKUM, AlbaNova, Stockholm University, Stockholm
- F. Loehl, E. Saldin, H. Schlarb, E. Schneidmiller, M. V. Yurkov
DESY, Hamburg
- A. Meseck
BESSY GmbH, Berlin
|
|
| |
We present experimental results from the optical replica synthesizer, a novel device to diagnose sub-ps electron bunches by creating a coherent optical pulse in the infrared that has the envelope of the electron bunch and analyzing the latter by frequency resolved optical gating methods. Such a device was recently installed in FLASH at DESY. During an experiment period the spatial and temporal overlap of a several ps long electron bunch and a 200 fs laser pulse were achieved within an undulator. Coherent transition radiation due to the induced micro-bunching was observed on a silver-coated silicon screen and varying the timing between electrons and laser pulse produced two-dimensional images of the slices as a function of the longitudinal position within the electron bunch. In a second experiment the strongly compressed electron bunch is modulated by a laser pulse lengthened to about 2 ps and replica pulses that are emitted from a second undulator are observed and diagnosed by frequency resolved optical gating methods.
|
|
| WEPP077 |
The XFEL Laser Heater
|
2695 |
| |
- V. G. Ziemann, G. Angelova
UU/ISV, Uppsala
- M. Dohlus, Y. A. Kot
DESY, Hamburg
|
|
| |
The high-brilliance photo-cathode gun foreseen for the X-FEL will provide beams with extremely small momentum spread that will make the beam susceptible to micro-bunching instabilities which will spoil SASE operation. It is therefore desirable to increase the momentum spread to a level that prevents these instabilties but still is compatible with SASE operation. The laser heater will achive this by superimposing a transversely polarized laser and the electron beam in a properly tuned undulator, thereby producing a momentum modulation that is smeared out in a dogleg chicane to obtain the desired momentum spread increase. We present the initial design and layout of the laser heater system for the X-FEL in Hamburg.
|
|
| WEPP131 |
RF-breakdown Experiments at the CTF3 Two-beam Test-stand
|
2800 |
| |
- M. Johnson, T. J.C. Ekelöf, R. J.M. Y. Ruber, V. G. Ziemann
UU/ISV, Uppsala
- H.-H. Braun
CERN, Geneva
|
|
| |
The Two-beam Test-stand (TBTS) in the CLIC Test Facility CTF3 offers unique possibilities to conduct RF-breakdown related experiments on the accelerating structures and the power extraction and transfer structures with beam. We report on the set-up of two such experiments, one for the measurement of the transverse kick and the other for the measurement of positive ion currents. The purpose of the transverse kick measurements is to determine the effects of a RF-breakdown event on the beam. Five BPMs in the TBTS will be used to study the trajectory of a pulse train after a RF-breakdown event, with important implications for the operation of CLIC. Ion currents ejected from accelerating structures during RF-breakdown events have already been observed at the 30 GHz test stand at the present test facility. Results and their implications for RF-breakdown physics are presented, as well as plans for similar measurements at the TBTS.
|
|
| WEPP139 |
The CTF3 Two-beam Test-stand Installation and Experimental Program
|
2821 |
| |
- V. G. Ziemann, T. J.C. Ekelöf, M. Johnson, R. J.M. Y. Ruber
UU/ISV, Uppsala
- H.-H. Braun, S. Doebert, G. Geschonke, G. Riddone, J. P.H. Sladen, I. Syratchev, W. Wuensch
CERN, Geneva
|
|
| |
The Two-beam Test-stand in CTF3 will be used to investigate the power-generation and accelerating structures for the Compact Linear Collider CLIC. We report on its design and construction which was recently completed and discuss the imminent commissioning phase as well as the following experimental program that initially will be devoted to the test of power generation structures in the drive-beam.
|
|