Rudi's major achievements
Neutron physics
Radiation and metrology
Mass-spectrometric gas analysis
Vacuum and surface technology
International relations and congress organization
Radiation and metrology
4π-anticoincidence proportional counter
Design and construction of a novel "wall-less" proportional counter exhibiting high-efficient anticoincidence in radial and axial direction as well as extremely-low background in gamma-radiation fields (range up to 10 Sv/h): R. Dobrozemsky,
Smn 173-24 (1965) 331;
Sitzungsber. Österr. Akad. Wiss., Mathem.-naturwiss. Kl., Abt. II, 173 Bd.; Springer, Wien 1965. Rudi's development of this counting principle, and the implementation of a
H2-filled proportional counter of this type for his neutron spectroscopy studies was a significant contribution to the completion of his thesis at Vienna University of Technology.
Drawing of the 4π-anticoincidence proportional counter.
The cylindrical counting volume (Z) is defined by a number of thin wires (K).
Shielding in radial direction is achieved by means of a cylindrical arrangement
of proportional counters (S), whereas the length of the counting volume is
defined by the two grids G1 and G2 situated at both ends of the counting volume.
These helically shaped wires, mounted coaxially to the central anode and
serving as capacitive pick-up electrodes, are the essential elements for the "wall-less" operation: The signals detected by the grids G1 and G2 allow
- in combination with a correspondingly tailored electronic circuit - to
determine the position of particle tracks in axial direction with respect to
planes E1 and E2. Together with the cylindrical ring of proportional counters (S), efficient shielding of the counting volume could be achieved in every direction.
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Main section of Rudi's 4π-anticoincidence
proportional
counter (1962).
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Center: Acrylic glass chamber for testing
axial and radial anticoincidence by means
of a narrow α-beam. Left: 1962-model
and casing. Right: 1965-model and casing.
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Multi-chamber Geiger-Müller and proportional counters:
High counting efficiency and short dead-time
G.M. and proportional counters for low-energy gamma radiation with efficiencies of up to 22% (i.e., more than ten times that of conventional counters of this kind) and short dead time, utilizing several rectangular counting chambers in a row, very thin anode wires, and high pressure Xe-Br filling (industrial contract 1968). Exploration of the potential of various multi-wire arrangements towards extremely-short dead time.
Radiation shielding inside "open" reactor beam tubes
Novel design criteria for reactor beam-tubes, yielding extremely-high axial shielding factors for "open" layouts, i.e., beam tubes with no absorbers placed along the axis: R. Dobrozemsky, Nucl. Instrum. Methods 118
(1974) 1.
RID, REP, and radiation effects on magnetic materials
Exploration of reactor-radiation effects on outgassing (Radiation-Induced Desorption - RID): E. Baltacis, R. Dobrozemsky, and
W. Kubischta, Proc. 4th Internat.
Vac. Congr. (Manchester 1968), p. 767, measurement
of Radiation-Enhanced Permeation - REP: R. Dobrozemsky, G. Schwarzinger, and Chr. Stratowa, Proc. 8th Internat.
Vac. Congr. (Cannes 1980), II, p. 15, and study of the effects of fission-reactor radiation on magnetic-shielding materials: R. Dobrozemsky
and E. Kerschbaum, Proc 2nd Internat. Conf. Magnet Technol. (Oxford 1967), p. 363.
Rudi's other major achievements
Neutron physics
Mass-spectrometric gas analysis
Vacuum and surface technology
International relations and congress organization
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