| AVS 61st International Symposium & Exhibition | |
| Vacuum Technology | Wednesday Sessions |
| Session VT-WeA |
| Session: | Accelerator and Large Vacuum Systems II |
| Presenter: | Karl Smolenski, Cornell University |
| Authors: | K. Smolenski, Cornell University X. Liu, Cornell University B. Dunham, Cornell University L. Cultrera, Cornell University J. Conway, Cornell University |
| Correspondent: | Click to Email |
The Cornell DC photoelectron guns pose a series of challenging vacuum engineering problems. These high brightness electron sources have produced the highest currents (0.075A) yet achieved from a photocathode source and are prototypes for future state of the art accelerators. The guns operate in the XHV (<1e-11 Torr) with massive NEG pumping and require exchange of the photocathode wafer periodically for continuous operation. The scale of the vacuum vessel, set by the extreme high voltages, requires the use of meter scale transfer arms to load and extract the photocathode holder with minimal disruption to the vacuum level and without particulate generation. These transfers are required to be rapid and simple to minimize operational downtown.
We have developed a series of mechanisms to retain the photocathodes, magnetic and bellows-coupled transfer arms to move samples between chambers, and load locks to introduce cathodes into the vacuum systems. More recently vacuum suitcases have been employed to move photocathodes from remote labs to our accelerators and to other laboratories for testing. This talk will present our experiences maintaining large scale systems with extensive in-vacuum motions under extreme requirements.