Abstract :
A nuclear reactor designed exclusively for biological research has been operated for the first time at the United States Atomic Energy Commission´s Argonne National Laboratory. The reactor, situated at the Argonne site southwest of Chicago, is named Janus after the two-faced Roman god, because it has two “faces,” or openings. By a shutter arrangement, either or both of the faces (which are placed on either side of the reactor) can be opened, allowing living organisms to be exposed to high or low levels of neutron radiation. The design allows the reactor to provide different intensities of fission neutrons at its two radiation faces.
