The program of measurements at SLAC on superconduct. I ;r. ing niobium cavities is described. Results for TE and TM mode X-band cavities are presented. An RF magnetic breskdown field of 960 gauss and Q values greater than 1011 were measured for an electron beam welded TEOII mode cavity at ‘I 10.5 GHz. The best result for a TM mode cavity was a Q of 1.4 x log and a breakdown field of 360 gauss, ...

With quality factors (Q) often-exceeding 10,000, vibrating micromechanical resonators have emerged as leading candidates for on-chip versions of high-Q resonators used in wireless communications systems. However, as in the case for transistors, extending the frequency of MEMS resonators generally entails scaling of resonator dimensions. Unfortunately, smaller size often coincides with lower-pow...

Obstructive apnea and voluntary breath holding are associated with transient increases in muscle sympathetic nerve activity (MSNA) and arterial pressure. The contribution of changes in blood flow relative to the contribution of changes in vascular resistance to the apnea-induced transient rise in arterial pressure is unclear. We measured heart rate, mean arterial blood pressure (MAP), MSNA (per...

The present paper addresses reference dose measurements using thimble ionization chambers for quality assurance in IMRT fields. In these radiation fields, detector fluence perturbation effects invalidate the application of open-field dosimetry protocol data for the derivation of absorbed dose to water from ionization chamber measurements. We define a correction factor C(Q)IMRT to correct the ab...