We report the design, fabrication, and preliminary characterization of a compact Xray generator for improved X-ray absorption imaging that uses a nanostructured field emission cathode (FEC) as the electron source and a microstructured transmission anode as the X-ray generating element. FECs consume less power, respond faster, and tolerate lower vacuum than thermionic cathodes used in convention...

The next generation light sources such as energy recovery linac (ERL) light sources and X-ray FEL oscillator require high brightness electron gun with megahertz repetition rate. We have developed a DC photoemission electron gun at JAEA for the Japanese ERL light source project. This DC gun employs a segmented insulator with guard rings to protect the insulator from field emission generated from...

An 18 MeV electron photo-injector facility was constructed at Fermilab in collaboration with UCLA, INFNMilano, University of Rochester, and DESY. The photoinjector is now being operated in partnership with the Northern Illinois Center for Accelerator and Detector Development. The facility consists of an RF gun [1, 2] with a cesium telluride (Cs2Te) photo-cathode [3] excited by a pulsed ultra-vi...

multilayer planar cold cathode R. Z. Wang, H. Yan, B. Wang, X. W. Zhang, and X. Y. Hou Laboratory of Thin Film Materials, College of Materials Science and Engineering, Beijing University of Technology, Beijing 100022, People’s Republic of China Key Laboratory of Semiconductor Materials Science, Institute of Semiconductors, Chinese Academy of Sciences, P.O. Box 912, Beijing 100083, People’s Repu...

A photocathode RF gun was built and it has been operated for beam measurement at SPring-8. The cavity was tested by using high power RF up to 18 MW. The electric field gradient on the cathode reached 127 MW/m. After RF conditioning, a laser pulse was irradiated on a copper cathode and the photo-emitted beam was accelerated up to 2.9 MeV. An effective quantum efficiency of the cathode was obtain...

Cold cathode emission wa,H ubtaxncd for devices fabricated usinK Si SnO., heterojunctions. Due to excessive heating the devices failed before photo measurements could be made. Devices fabricated by "etching" silicon either single crystal or expitaxial. exhibited no electron emission. "tttmamamBsss^Mm: PRßCSDDC PAGE BL4NK-N0T FIIWED

Observing single electron pulses provides insight into the mechanism that leads to sudden high current jumps (breakdown) in aged wire chambers. This single electron activity is found to be consistent with the Fowler-Nordheim equation for field emission of electrons from a cathode surface in a high electric field. The high electric field arises from the positive ion buildup on a very thin insula...