ASTRA (Adaptierter Schwimmbecken-Typ-Reaktor Austria, English translation: Adapted swimming pool-type reactor Austria) was a type of

nuclear research reactor Research reactors are nuclear fission-based nuclear reactors that serve primarily as a neutron source. They are also called non-power reactors, in contrast to power reactors that are used for nuclear power plant, electricity production, heat ge ...

built in

Seibersdorf Seibersdorf is an Austrian market town with 1,283 residents in the District of Baden in Lower Austria. Geography Seibersdorf lies in the industrial belt of Lower Austria. The municipality has an area of 20.2 km2, 9.36 percent of which is for ...

Austria Austria, formally the Republic of Austria, is a landlocked country in Central Europe, lying in the Eastern Alps. It is a federation of nine Federal states of Austria, states, of which the capital Vienna is the List of largest cities in Aust ...

near

Vienna Vienna ( ; ; ) is the capital city, capital, List of largest cities in Austria, most populous city, and one of Federal states of Austria, nine federal states of Austria. It is Austria's primate city, with just over two million inhabitants. ...

, at the site of the former Austrian Reactor Center Seibersdorf which now forms part of the

Austrian Institute of Technology AIT Austrian Institute of Technology is Austria's largest Research and Technology Organization (RTO), employing about 1,400 people mostly based at the main facilities Vienna Giefinggasse, Seibersdorf, Wiener Neustadt, Ranshofen, and Graz. In June ...

(AIT). ASTRA operated from 1960 to 1999.

Timeline

Research

One of the most advanced experiments in physics carried out at the ASTRA reactor was an experiment on the decay of free

neutron The neutron is a subatomic particle, symbol or , that has no electric charge, and a mass slightly greater than that of a proton. The Discovery of the neutron, neutron was discovered by James Chadwick in 1932, leading to the discovery of nucle ...

s. In this experiment, the electron-neutrino angular correlation in free neutron decay was measured via the shape of the energy spectrum of the recoil

proton A proton is a stable subatomic particle, symbol , Hydron (chemistry), H+, or 1H+ with a positive electric charge of +1 ''e'' (elementary charge). Its mass is slightly less than the mass of a neutron and approximately times the mass of an e ...

s; 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 g_A and g_V of the

weak interaction In nuclear physics and particle physics, the weak interaction, weak force or the weak nuclear force, is one of the four known fundamental interactions, with the others being electromagnetism, the strong interaction, and gravitation. It is th ...

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 , g_A/g_V, = 1.259 ± 0.017. This is in good agreement with the later (much more accurate) average g_A/g_V = - 1.2695 ± 0.0029; this value was measured using polarised neutrons and hence contains also the sign of the ratio.

Literature

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

References

External links

Announcement of planned shutdown from ARC''Planning for the Decommissioning of the ASTRA-Reactor''
, an IRPA paper from ARC (PDF)
2001 European Commission legal opinion concerning the disposal of nuclear waste from decommissioning ASTRA
{{Coord, 47.9594, N, 16.51584, E, display=title Nuclear research reactors Science and technology in Austria Nuclear technology in Austria