Rudi's major achievements

Neutron physics
Radiation and metrology
Mass-spectrometric gas analysis
Vacuum and surface technology
International relations and congress organization

Neutron physics

Neutron decay

Determination of the electron-neutrino angular correlation coefficient in free-neutron decay.
Method: Measurement of the energy spectrum of the recoil protons obtained from neutron decay. Source: "Thermal neutron gas" in the innermost region of an evacuated tangential beam tube of the ASTRA reactor. Energy spectrometer: Electrostatic spherical condenser outside the biological shield of the reactor. Double-layer magnetic shield for beam tube, energy spectrometer, and reference proton source. Aluminum beam tube: In-situ bakeable double-wall uhv system with vacuum level in the 10-9 mbar range throughout the entire vacuum system. Proton counting: Ion-electron-converter detector and coincidence technique (background approx. 1 cpm). Reference proton source for the purpose of calibration.
Results: By adding up multi-year measurement data, the electron-neutrino angular-correlation coefficient a was determined as - 0.1017 ± 0.0051, leading to a value

    GA/GV = 1.259 ± 0.017

for the ratio of the axial and vectorial coupling constants in weak interaction (Phys. Rev. D18 (1978) 3970) - still the most precise data for this fundamental physical constants achieved from a measurement on free unpolarised neutrons.


General arrangement drawing of the apparatus employed for the neutron-decay measurement 1964 - 1978


Neutron-decay apparatus at its final rest in Rudi's backyard.
Consistently original parts except for the shortened horizontal beam tube
in the center of the photo. In the fore the reference-proton-source section
with the vertical pumping line leading to the sputter-ion pump on the top.
In the rear the proton-energy analyzer (spherical condenser spectrometer
and detector) with the vertical Orbion ultrahigh vacuum pump and beam
catcher (in red) in the very back. A section of the core grid plate (holding
a vertical reflector rod) is attached to the middle of the beam tube.

Thermal neutron gas

Elaboration of prerequisites for a clean neutron gas for decay and scattering experiments with a density exceeding that of the background gases and with an extremely-low radiation background in the experimental area: Nucl. Instrum. Methods 118 (1974) 1-37.

Neutron energy spectroscopy

First measurement of the low-ener y neutron spectrum of a PuBe-source: R. Dobrozemsky, Smn 173-24 (1965) 331; Sitzungsber. Österr. Akad. Wiss., Mathem.-naturwiss. Kl., Abt. II, 173 Bd.; Springer, Wien 1965 (part of Rudi's thesis at University of Vienna).

Neutron cross-sections

Measurement of pile-neutron capture cross sections of rare-earth isotopes by means of the mass-spectrometric method: Nuclear Data for Reactors I (1967) 495.

Coated particles

The fission-product distribution in irradiated coated particles of High Temperature Gas-Cooled Reactor (HTGR - an inherently safe, modular, underground helium-cooled nuclear reactor technology) have been studied by means of the ion-sputtering technique: J. Nucl. Materials 38 (1971)  77.

AUSTRON target

The AUSTRON project was a proposal to create an international research centre based on a pulsed neutron spallation source in Central Europe. The AUSTRON target station, based on a W-Re target designed at ARCS, is described e.g. in Physica B: Condensed Matter 213-214 (1995) 851-853.
The AUSTRON project was the seed and fertilizer for the ion-therapy center Med-Austron.

Radiation and metrology
Mass-spectrometric gas analysis
Vacuum and surface technology
International relations and congress organization

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