CLASSE, Ithaca, New York
Funding: Work supported by the National Science Foundation under contract PHY 0131508
Cornell University is planning to build an Energy-Recovery Linac (ERL) X-ray facility. The very small electron-beam emittance would produce an X-ray source that is significantly better than any existing storage-ring based light source. One major difference between an ERL and a typical light source is that the final electron beam emittance, and thus the X-ray beam brightness, is determined by the electron injector rather than the storage ring. We are currently constructing and commissioning an injector for an ERL with the goal of demonstrating the low emittances and high beam power required. The injector is designed to accelerate up to 100 mA cw electron bunches of 77 pC/bunch with an energy of 5 MeV (33 mA at 15 MeV) using 1.3 GHz superconducting cavities. A full suite of diagnostics will allow a complete phase space characterization for comparison with simulations and with the requirements. We will describe the current status of the injector along with results, difficulties and challenges to date.
CLASSE, Ithaca, New York
Cornell University, Ithaca, New York
Funding: DOE and NSF
Quench detection for 9-cell LLC cavities is presently a cumbersome procedure requiring two or more cold tests. One is to identify the cell-pair involved via quench field measurement in several pass band modes, followed by a second cold test with many fixed thermometers attached to the culprit cell-pair to identify the particular cell, and possibly a third measurement to zoom in on the quench spot with many localized fixed thermometers. We report here on a far more efficient alternative method which utilizes a few (e.g. 8) oscillating super-leak transducers to detect the He-II second sound wave driven by the defect induced quench. Results characterizing defect location on a 9-cell reentrant cavity with He-II second sound detection and corroborating measurements with carbon thermometers will be presented.