Results of an RF Pulsed Heating Experiment at SLAC

Results are reported from an experiment on RF pulsed heating of copper at SLAC. Damage in the form of cracks may be induced on the surface after the application of many pulses of RF. The experiment consists of two circularly cylindrical cavities operated in the TE011 mode at a resonant frequency of 11.424 GHz. Each cavity received 8.5 MW, 1.2 microsecond pulses at 60 Hz corresponding to a calculated temperature rise of 120 K on the copper surface. After 5.5 x 10^7 pulses, the experiment was stopped and the copper surfaces were examined. Damage is present on the area of the surface where the maximum heating occurred.Comment: 3 pages, 7 figures, Presented at LINAC 2000 conference, Paper ID THA1

Photonic Crystal Laser Accelerator Structures

Photonic crystals have great potential for use as laser-driven accelerator structures. A photonic crystal is a dielectric structure arranged in a periodic geometry. Like a crystalline solid with its electronic band structure, the modes of a photonic crystal lie in a set of allowed photonic bands. Similarly, it is possible for a photonic crystal to exhibit one or more photonic band gaps, with frequencies in the gap unable to propagate in the crystal. Thus photonic crystals can confine an optical mode in an all-dielectric structure, eliminating the need for metals and their characteristic losses at optical frequencies. We discuss several geometries of photonic crystal accelerator structures. Photonic crystal fibers (PCFs) are optical fibers which can confine a speed-of-light optical mode in vacuum. Planar structures, both two- and three-dimensional, can also confine such a mode, and have the additional advantage that they can be manufactured using common microfabrication techniques such as those used for integrated circuits. This allows for a variety of possible materials, so that dielectrics with desirable optical and radiation-hardness properties can be chosen. We discuss examples of simulated photonic crystal structures to demonstrate the scaling laws and trade-offs involved, and touch on potential fabrication processes.Comment: 3 pages, 3 figures; Submitted to Particale Accelerator Conference (PAC 2003), May 12-16, 2003, Portland, Oregon (IEEE

Zika Virus Infects Human Sertoli Cells And Trespasses The Blood-Testes Barrier To Gain Entry Into The Seminiferous Epithelium

M.S. Thesis. University of Hawaiʻi at Mānoa 2017