0000000000659076
AUTHOR
L. Fleischmann
The status of the Mainz neutrino mass experiment
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
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) .
Improved limit on the electron-antineutrino rest mass from tritium ß-decay
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 .
On dewetting dynamics of solid films of hydrogen isotopes and its influence on tritium [Beta] spectroscopy
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.