| Paper |
Title |
Page |
| WEO2A01 |
Beam Diagnostics for the Front End Test Stand at RAL
|
218 |
| |
- S. Jolly, D. A. Lee, P. Savage
Imperial College of Science and Technology, Department of Physics, London
- D. C. Faircloth, J. K. Pozimski
STFC/RAL, Chilton, Didcot, Oxon
- C. Gabor
STFC/RAL/ASTeC, Chilton, Didcot, Oxon
|
|
| |
The Front End Test Stand (FETS) at the Rutherford Appleton Laboratory (RAL) is intended to demonstrate the early stages of acceleration (0-3MeV) and beam chopping required for high power proton accelerators, including proton drivers for pulsed neutron spallation sources and neutrino factories. The FETS ion source is required to produce a 60 mA beam in pulses up to 2ms long at up to 50 pps with an RMS emittance of 0.3 π mm mrad. A number of different diagnostic systems are currently under development to provide precise measurements of the H- ion beam. A pepperpot emittance measurement system, which is also capable of high resolution transverse beam density measurements, has been designed for use on the ISIS ion source development rig. This system is capable of sub-microsecond time-resolved measurements at a range of positions along the beam axis. Details are given of the improvements to the current design, including extensive tests on suitable scintillators and emittance and profile measurements are presented. Additionally, the designs of two different novel laser diagnostic systems for FETS are also presented.
|
|
| 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.
|
|
| WEO2A03 |
Advanced Measurements at the SPARC Photoinjector
|
224 |
| |
- A. Cianchi, L. Catani
INFN-Roma II, Roma
- D. Alesini, M. Bellaveglia, R. Boni, M. Boscolo, M. Castellano, E. Chiadroni, A. Clozza, L. Cultrera, G. Di Pirro, A. Drago, A. Esposito, M. Ferrario, D. Filippetto, V. Fusco, A. Gallo, G. Gatti, A. Ghigo, M. Incurvati, C. Ligi, E. Pace, L. Pellegrino, R. Ricci, C. Ronsivalle, C. Sanelli, M. Serio, F. Sgamma, B. Spataro, F. Tazzioli, S. Tomassini, C. Vaccarezza, M. Vescovi, C. Vicario
INFN/LNF, Frascati (Roma)
- A. Bacci, S. Cialdi, A. R. Rossi, L. Serafini
INFN-Milano, Milano
- A. M. Cook, M. P. Dunning, P. Frigola, P. Musumeci, J. B. Rosenzweig
UCLA, Los Angeles, California
- L. Giannessi, M. Quattromini
ENEA C. R. Frascati, Frascati (Roma)
- M. Migliorati, A. Mostacci, L. Palumbo
Rome University La Sapienza, Roma
- M. Petrarca
INFN-Roma, Roma
|
|
| |
The objective of the first stage of the SPARC commissioning was the optimization of the RF-gun setting that best matches the design working point and a detailed study of the emittance compensation process providing the optimal value of emittance at the end of the linac. For this purpose an innovative beam diagnostic, the emittance-meter, consisting of a movable emittance measurement system, was conceived and built. More than a simple improvement over conventional, though non-trivial, beam diagnostic tools this device defines a new strategy for the characterization of new high performance photo-injectors. The emittance meter allows to measure at different location along the beamline the evolution of important beam parameters both in longitudinal and in the transverse phase space such as beam sizes, energy spread and rms transverse emittances in a region where the space-charge effect dominate the electron dynamics. The quality and the amount of the data allowed a clear reconstruction of the phase space evolution. We report also the first experimental observation of the double emittance minima effect on which is based the optimized matching with the SPARC linac
|
|