ASTRA (reactor)

From Wikipedia, the free encyclopedia
Jump to navigation Jump to search

ASTRA was a type of nuclear research reactor built in Seibersdorf, Austria near Vienna, at the site of the former Austrian Reactor Center Seibersdorf which now forms part of the Austrian Institute of Technology (AIT). The acronym stands for Adaptierter Schwimmbecken-Typ-Reaktor Austria (Adapted swimming pool-type reactor Austria). ASTRA operated from 1960 to 1999.


September 1960 100kW (initial criticality)
May 1962 1MW
August 1962 5MW
August 1969 6MW
1972 7MW
January 1975 8MW
~1989 9.5MW
1999 decommissioned


One of the most advanced experiments in physics carried out at the ASTRA reactor was an experiment on the decay of free neutrons.[1] In this experiment, the electron-neutrino angular correlation in free neutron decay was measured via the shape of the energy spectrum of the recoil protons; the center of a highly evacuated tangential beam tube of the reactor served as neutron source.

The aim was to determine the ratio of the two coupling constants gA and gV of the weak interaction from the shape of the recoil proton spectrum. This spectrum was measured using an electrostatic spectrometer; the protons were counted using an ion electron converter of the coincidence type.

The result was[2] |gA/gV| = 1.259 ± 0.017. This is in good agreement with the later (much more accurate) average[3] gA/gV = - 1.2695 ± 0.0029; this value was measured using polarised neutrons and hence contains also the sign of the ratio.


  • R. Dobrozemsky: Production of a Clean Neutron Gas for Decay and Scattering Experiments. In: Nuclear Instruments and Methods. 118 (1974) 1–37.


  1. ^ R. Dobrozemsky, E. Kerschbaum, G. Moraw, H. Paul, C. Stratowa, P. Weinzierl: Electron-neutrino angular correlation coefficient a measured from free-neutron decay. in: Physical Review. D 11 (1975), 510.
  2. ^ C. Stratowa, R. Dobrozemsky, P. Weinzierl: Ratio |gA/gV| derived from the proton spectrum in free neutron decay. in: Physical Review. D 18 (1978), 3970
  3. ^ J. Beringer et al. (Particle Data Group), Phys. Rev. D 86, 0100001 (2012)

External links[edit]

Coordinates: 47°57′34″N 16°30′57″E / 47.9594°N 16.51584°E / 47.9594; 16.51584