ASTRA 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 electricity production, heat generation, or maritim ...

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 fo ...

Austria Austria, , bar, Östareich officially the Republic of Austria, is a country in the southern part of Central Europe, lying in the Eastern Alps. It is a federation of nine states, one of which is the capital, Vienna, the most populous ...

near

Vienna en, Viennese , iso_code = AT-9 , registration_plate = W , postal_code_type = Postal code , postal_code = , timezone = CET , utc_offset = +1 , timezone_DST ...

, 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 1,300 people mostly based at the main facilities Vienna Tech Gate, Vienna TECHbase, Seibersdorf, Wiener Neustadt, Ranshofen and G ...

(AIT). The acronym stands for Adaptierter Schwimmbecken-Typ-Reaktor Austria (Adapted

swimming pool-type reactor NC State's PULSTAR Reactor is a 1 MW pool-type research reactor with 4% enriched, pin-type fuel consisting of UO2 pellets in zircaloy cladding.image:Pulstar1.jpg, The control room of North Carolina State University, NC State's Pulstar Nuclear R ...

Austria). 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 , which has a neutral (not positive or negative) charge, and a mass slightly greater than that of a proton. Protons and neutrons constitute the nuclei of atoms. Since protons and neutrons beh ...

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 , H+, or 1H+ with a positive electric charge of +1 ''e'' elementary charge. Its mass is slightly less than that of a neutron and 1,836 times the mass of an electron (the proton–electron mass ...

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, which is also often called the weak force or weak nuclear force, is one of the four known fundamental interactions, with the others being electromagnetism, the strong 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 , 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