| Paper | Title | Page |
|---|---|---|
| WEPMS035 | Measurement of the UCLA/URLS/INFN Hybrid Gun | 2418 |
|
||
|
Funding: This work performed under the auspices of the U. S. Department of Energy under contract numbers DE-FG-98ER45693 and DE-FG03-92ER40693. The hybrid photoinjector is a high current, low emittance photoinjector/accelerator and is under design and collaboration at Roma University La Sapienza, INFN - Laboratori Nazionali di Frascati and the UCLA Particle Beam Physics Lab. The hybrid standing wave-traveling wave photoinjector uses a coupling cell to divide power between a high-field 1.6 cell standing wave photoinjector, for electron emission and collection, and a low power traveling wave accelerator, for acceleration to desired energies at low emittances. Simulation results show promising beam properties of less than 4 mm-mrad emittance, energy spreads of 1.5%, and currents as high as 1.2 kA at energies of 21 MeV. We report on the progress of RF design and results of cold test RF measurements at the UCLA Pegasus Laboratory, including methods for measurements and difficulties arising in the transition from simulation to physical measurements. |
||
| THPAS052 | Charge and Wavelength Scaling of the UCLA/URLS/INFN Hybrid Photoinjector | 3609 |
|
||
| Short-bunched beam is required for the improving the emission of the free electron laser and wakefield accelerations, as well as low emittance beam. To achieve both of short length and low emittance, we are developing SW/TW Hybrid gun. Two standing wave cells make a photocathode RF gun and the gun is connected directory to the input coupler of the traveling wave structure, and the total length is about 3 m. The low emittance beam produced in the RF gun is bunching in the traveling wave structure in the scheme of, so called, "velocity bunching". PARMELA simulation shows that 1 nC bunch can be achieve 3.0 mm.mrad for the normalized rms emittance and 0.14 mm for the rms bunch length, simultaneously. We also calculates the cases of 1 pC bunch in S-band and 250 pC bunch in X-band to get shorter bunch length and lower emittance. 1 pC bunch is scaled to 1/1000 in its volume (one-tenth for each dimension). It can result in 0.0047 mm short while the emittance is 0.091 mm.mrad. In X-band case, where the structures are scaled down one-fourth in the length and four times in the field strength, the bunch length and the emittance are 0.027 mm and 1.1 mm.mrad, respectively. |