0000000001315731
AUTHOR
E.w. Otten
Direct neutrino mass measurements
The paper reports on recent progress and developments since the neutrino '92 conference in the search for finite neutrino masses by direct mass measurements. Regarding the mass of μ - and τ -neutrino experiments have been finished and come up with somewhat improved upper bounds; the negative m 2 -value for the μ -neutrino could be removed mostly. Indications of a 17 keV neutrino component in β -decay spectra have been disproved by a number of alternative experiments as well as by reanalysis of part of the original data. Regarding the electron neutrino mass, measurements by magnetic spectrometers are phasing out in favour of electrostatic filters with magnetic guiding fields. These experimen…
Effects of scintillation light collection on the time resolution of a time-of-flight detector for annihilation quanta
Monte Carlo methods were used to simulate the production and collection of scintillation light in a BaF/sub 2/ crystal. The calculated results were compared to measured values for detectors with different heights. Based on this simulation, a TOF (time-of-flight) detector consisting of two conical BaF/sub 2/ crystals (base radius 18 mm, top radius 15 mm, height 25 mm) was assembled. The total time resolution of this system was (210+or-5) ps FWHM (full width at half maximum) for 511-keV annihilation quanta and was found to be independent of the source position between the detectors. Since the time resolution of the TOF detector system consisting of two conical BaF/sub 2/ crystals is sufficien…
A solenoid retarding spectrometer with high resolution and transmission for keV electrons
Abstract We have built an electrostatic electron spectrometer combining both high resolution and large luminosity. The instrument consists essentially of two superconducting solenoids separated by a system of ring electrodes of 4 m in length. Source and detector are placed in the high-field regions of the superconducting solenoids, whereas the repellent analyzing electrostatic potential of the ring electrodes peaks at the minimum of the magnetic field in between these solenoids. The magnetic guiding field provides (i) the acceptance of the full foreward solid angle of 2π, (ii) the transformation of the transverse cyclotron motion into longitudinal motion parallel to the magnetic field. The …
Optical pumping and unstable nuclei
The paper reviews the application of optical pumping to short-lived nuclei, where either the nuclear polarisation is detected by the β-decay asymmetry or the atomic polarisation by Stern-Gerlach-analyzer. Moreover the paper deals with collinear laser spectroscopy on beams of short-lived, mass-separated isotopes. The aim of the experiments is the systematic investigation of nuclear structure through the determination of spin, moments and charge radii from the hyperfine structure and isotopic shift of the atomic spectra. The impact of these experiments on the theory of nuclear forces and structure is discussed by means of a few examples.
"Table 1" of "First measurement of the polarization transfer on the proton in the reactions H (e (polarized), e-prime p (polarized)) and D (e (polarized), e-prime p (polarized))"
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