Search results for "doppler"
showing 10 items of 637 documents
First demonstration of Doppler-free 2-photon in-source laser spectroscopy at the ISOLDE-RILIS
2020
Abstract Collinear Doppler-free 2-photon resonance ionization has been applied inside a hot cavity laser ion source environment at CERN-ISOLDE. An injection-seeded Ti:sapphire ring laser was used to generate light pulses with a Fourier-limited linewidth for high-resolution spectroscopy. Using a molybdenum foil as a reflective surface positioned at the end of the target transfer line, rubidium was successfully ionized inside the hot cavity. The results are presented alongside previously obtained data from measurements performed at the RISIKO mass separator at Mainz University, where collinear and perpendicular ionization geometries were tested inside an RFQ ion guide. This work is a pre-curs…
Lifetime measurements of excited states in $^{163}$W and the implications for the anomalous B(E2) ratios in transitional nuclei
2019
Grahn, Tuomas/0000-0002-6255-2279; Herzan, Andrej/0000-0002-6736-7638; Cullen, Dave/0000-0002-0041-1606; Barber, Liam/0000-0002-7409-9352; Keatings, James Michael/0000-0003-4271-8021; SAYGI, BAHADIR/0000-0001-5406-506X; Greenlees, Paul/0000-0002-5986-5274; Spagnoletti, Pietro/0000-0002-7674-989X; Parr, Edward/0000-0001-6204-4461; Bondili, S Nara Singh/0000-0002-4096-2429
Doppler-broadening of gamma rays following muon capture: search for scalar coupling
2002
Abstract A precision measurement of the 277 keV γ ray produced by capturing muons in gaseous oxygen was performed using high-resolution HPGe detectors. The Doppler-broadened shape of this line is sensitive to the possible admixture into muon capture of genuine scalar interaction. This experiment complements, in the muon sector, in principle, similar ones undertaken recently in nuclear β decay. Using a procedure discussed in earlier papers, a fit to the experimental line-shape allowed us to obtain for the recoil–gamma correlation coefficient the value of a 1 2 =0.096±0.041 (95% CL). The available evaluations of the contributing nuclear matrix elements, performed in the impulse approximation …
Determination of the intrinsic quadrupole moment of the superdeformed band in 143Eu
1995
The intrinsic quadrupole moment, Q0, of the superdeformed band in 143Eu has been extracted from nuclear lifetimes, measured in a Doppler shift attenuation method experiment. Data were collected with the NORDBALL gamma-ray spectrometer following the reaction 110Pd (37Cl, 4n) 143Eu at a beam energy of 160 MeV. A centroid shift analysis of the data was carried out, using the Braune stopping powers to model the slowing down of the recoil nuclei in the target and backing materials. This gave a value of Q0 = 13.0 ± 1.5 eb for the band. The result is in good agreement with the theoretical prediction of Total Routhian Surface calculations, and supports the assigned single particle configuration, in…
Prolate-oblate shape coexistence in Kr-75
1998
Abstract The collective bands of 75Kr were extended up to spin 45 2 using the compound reactions 50Cr(28Si,2pn), 54Fe(24Mg,2pn) and 58Ni(20Ne,2pn)75Kr. Lifetimes were measured by RDDS with nine OSIRIS detectors in coincidence. Mixing ratios were determined by measurements of internal conversion coefficients, angular distribution and correlations. Deviations between different measurements are explained by the short lifetimes leading to angle dependent intensity losses due to Doppler shift. Spins and parities were assigned from angular distributions, excitation functions and DCO ratios measured with the OSIRIS_12 spectrometer. The band head spin of the negative parity yrast band was establish…
Blood flow and oxygenation status of human tumors. Clinical investigations.
1999
There is a large body of evidence suggesting that blood flow and oxygenation of human tumors are important research topics which may explain, in particular, resistance to radiation and to many antineoplastic drugs, which can limit the curability of solid tumors by radiotherapy and chemotherapy.This manuscript reviews the clinical investigations which have been performed regarding blood flow and oxygenation status of human tumors in radiation oncology.The possible uses and limitations of the prognostic significance and the changes under therapy measuring blood flow and oxygenation in human tumors were discussed. In addition, several approaches were summarized, which can improve the microvasc…
<title>Clinical potential of the side-glowing optical fibers</title>
1997
Unconventional designs of silica-core optical fibers providing efficient lateral emission through the cylindrical side surface have been developed and manufactured. A physical model of the side-glowing fibers, available experimental data and potential clinical applications of this type of lightguides are discussed. Promising, clinical applications can be expected in the following areas: (1) Phototherapy, including photo-dynamic therapy, soft-laser therapy and visible/UV broadband irradiation therapy. (2) Single-fiber laser Doppler flowmetry. (3) Laser-tissue dosimetry. (4) Linear and planar 'cold light' illumination. (5) Optical sensing of mechanical pressure.
Acoustic and optical variations during rapid downward motion episodes in the deep north-western Mediterranean Sea
2011
An Acoustic Doppler Current Profiler (ADCP) was moored at the deep-sea site of the ANTARES neutrino telescope near Toulon, France, thus providing a unique opportunity to compare high-resolution acoustic and optical observations between 70 and 170 m above the sea bed at 2475 m. The ADCP measured downward vertical currents of magnitudes up to 0.03 m s-1 in late winter and early spring 2006. In the same period, observations were made of enhanced levels of acoustic reflection, interpreted as suspended particles including zooplankton, by a factor of about 10 and of horizontal currents reaching 0.35 m s-1. These observations coincided with high light levels detected by the telescope, interpreted …
Analysis of the level-crossing rate and average duration of fades of WSSUS channels
2017
Studies of the level-crossing rate (LCR) and the average duration of fades (ADF) are so far only devoted to stochastic processes being a function of one independent variable, which is usually time or in some few cases frequency. In this paper, we study the LCR (ADF) of wide-sense stationary uncorrelated scattering (WSSUS) processes in the time-frequency domain. A closed-form solution will be derived for the so-called time-frequency LCR (ADF) of the absolute value of the time-variant transfer function (TVTF) of WSSUS processes. It is shown that the LCR (ADF) is circularly symmetric in the normalized time-frequency domain. The derived time-frequency LCR contains the time LCR and frequency LCR…
The direct effect of magnetic tape ® on pain and lower-extremity blood flow in subjects with low-back pain: A randomized clinical trial
2021
Low-back pain has a high impact on the world population, and solutions are in demand. The behavior of specific physiological processes has been modified using magnetic fields, whether for pain relief, bone consolidation, or improvement of vascularization. The use of tape with magnetic properties could help in these cases. A double-blind randomized clinical trial was designed to use Magnetic Tape® versus placebo Kinesio tape. Blood flow variables were evaluated using pulsed power Doppler ultrasound. Resistance index, pulsatility index, systolic velocity, and diastolic velocity were measured. The pressure pain threshold was measured using algometry in 22 subjects. The results reveal significa…