William M. Fairbank

A New Noninvasive Technique for Cardiac Pressure Measurement: Resonant Scattering of Ultrasound from Bubbles

We suggest and analyze a new technique for making non-invasive cardiac measurements. The technique involves measurement of the spectrum of ultrasound scattered from small bubbles injected into the circulatory system as they pass through the heart. We show that the resonant frequency observed in these spectra will vary as the cardiac pressure changes. Thus the variations of the resonance can be calibrated to give the pressure excursions in a cardiac chamber. Preliminary bench tests of the method are described which show the predicted shift with pressure of the resonance frequency of bubbles in water.

Photon burst mass spectrometry for the measurement of {sup 85}Kr at ambient levels

Photon burst mass spectrometry has been used to measure 85Kr in a sample with an abundance of 6 X 10-9. Improvements in detection efficiency by the use of avalanche photodiodes cooled to liquid nitrogen temperature are reported, which should make possible measurement of 85Kr at the ambient atmospheric abundance of 10-11.

Isotope shifts and hyperfine structure of Pt i transitions in a hollow-cathode discharge

Saturation spectroscopy in a hollow-cathode discharge is used to measure isotope shifts and hyperfine splittings for the 270.24- and 270.59-nm transitions in Pt i. From a systematic analysis of these and other data, the following relative changes in nuclear-charge ratios are derived: 192–190 = 0.8164(45), 194–192 = 0.8997(26), 196–194 = 0.9253(17), 198–196 = 1, and 195–194 = 0.4254(16). An improved value of 63.95(3) mK is also derived for the hyperfine constant A of the 37769-cm−1 state. These constants are also used to assess the accuracy of techniques for extracting centroids, hyperfine constants, and isotope shifts from Fourier-transform spectra.

Measurement of the hyperfine structure and isotope shifts of the 3 s 2 3 p 2 3 P 2 → 3 s 3 p 3 3 D 3 o transition in silicon

The hyperfine structure and isotope shifts of the

Photon burst mass spectrometry: ultrasensitive detection of rare isotopes

3{s}^{2}3{p}^{2} {}^{3}{P}_{2}ensuremath{rightarrow}3s3{p}^{3} {}^{3}{D}_{3}^{o}

Measurement of trace isotopes by photon burst mass spectrometry

transition in silicon have been measured. The transition at 221.7 nm was studied by-laser induced fluorescence in an atomic Si beam. For

Detection of Photon Bursts from Single 200eV Mg Ions, Progress in Photon Burst Mass Spectrometry

^{29}mathrm{Si}

Isotopically selective atom counting using photon burst detection

, the hyperfine

Detection of fast Mg ions using the photon-burst method.

A

Measurement of the hyperfine structure of the 4d 2 D 3/2,5/2 levels and isotope shifts of the 4p 2 P 3/2 → 4d 2 D 3/2 and 4p 2 P 3/2 → 4d 2 D 5/2 transitions in gallium 69 and 71

constant for the