0000000000659074
AUTHOR
M. Przyrembel
showing 9 related works from this author
The status of the Mainz neutrino mass experiment
1998
Abstract The present status of the Mainz tritium β decay experiments is given. The very recent improvement of the Mainz setup and the first tritium data are presented.
A new upper limit of the electron anti neutrino rest mass from tritium β-decay
1993
Abstract A new upper limit of the electron anti neutrino rest mass has been deduced from the tritium β-decay spectrum. A source of molecular tritium has been investigated with a new solenoid retarding spectrometer. The results are m ν ϵ 2 = −38.8 ± 34.1 stat ± 15.1 syst (eV) 2 /c 4 from which we conclude m ν ϵ ≤ 7.2 eV/c 2 with 95% c.l. Our β-endpoint corresponds to a 3H-3He atomic mass difference of Δm( 3 H- 3 He) = 18590.8 ± 3 eV/c 2 (1σ) .
Wetting behavior of solid hydrogen films
1996
We have studied the dewetting of quench-condensed solid hydrogen films on bare and Ne plated Ag substrates. Information about the morphology of the films during the dewetting process is obtained from measurements of photoelectron tunneling through the films and complementary surface plasmon resonance data. Plating the Ag substrate with Ne films of various thickness allows to tune the strength of the van der Waals interaction with the hydrogen and thus to change the H2 films from a state of incomplete to complete wetting.
Improved limit on the electron-antineutrino rest mass from tritium ß-decay
1993
Abstract The endpoint region of the β-spectrum of tritium was remeasured by an electrostatic spectrometer with magnetic guiding field. It enabled the search for a rest mass of the electron-antineutrino with improved precision. The result is m2v=−39±34stat±15syst(eV/c2)2, from which an upper limit of mv m( T )−m( 3 He )=18 591±3 eV /c 2 .
Precision measurement of the conversion electron spectrum of 83mKr with a solenoid retarding spectrometer
1992
This paper reports on precision measurements of conversion lines in the decay of 83mKr with nuclear transition energies of 32.1 keV and 9.4 keV, respectively. The spectra were taken from a submonolayer surface of 83mKr frozen onto a cold backing, using the new Mainz solenoid retarding spectrometer. The high luminosity and resolution of this instrument enables the observation of all allowed conversion lines up to the N-shell and to fully separate the elastic component from inelastic satellites. The combined analysis of the data yields the transition energies Ey=32151.5±1.1 eV and 9405.9±0.8 eV, respectively. The experiment served also to pilot the application of this spectrometer to the ques…
Hydrogen and helium films as model systems of wetting
1997
Optical experiments on the wetting properties of liquid 4He and molecular hydrogen are reviewed. Hydrogen films on noble metal surfaces serve as model systems for studying triple point wetting, a continuous transition between wetting and non-wetting. By means of optically excited surface plasmons, the adsorbed film thickness for temperatures around, and far below, the bulk melting temperature is measured, and the physical mechanisms responsible for the transition are elucidated. Possible applications for other experiments in pure and applied research are discussed. Thin films are droplets of liquid helium are studied on cesium surfaces, on which there is a first order wetting transition. Ou…
A solenoid retarding spectrometer with high resolution and transmission for keV electrons
1992
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 …
On dewetting dynamics of solid films of hydrogen isotopes and its influence on tritium [Beta] spectroscopy
2000
The dewetting dynamics of solid films of hydrogen isotopes, quench-condensed on a graphite substrate, was measured at various temperatures below desorption by observing the stray light from the film. A schematic model describing the dewetting process by surface diffusion is presented, which agrees qualitatively with our data. The activation energies of different hydrogen isotopes for surface diffusion were determined. The time constant for dewetting of a quench-condensed T2 film at the working temperature of 1.86 K of the mainz neutrino mass experiment was extrapolated.
Stability of solid T2 films
1990
Abstract Films of molecular tritium, physisorbed on a cold substrate, have been investigated by means of ellipsometry. A significant effect of the radioactive decay processes on the desorption kinetics and the low temperature stability of these films is not observed.