The design and construction of a laboratory facility for the measurement of reactor moderator parameters

A Sigma Pile was constructed to serve as a laboratory facility at V.P.I.

Reproducible foil positions are possible with the positioning plates installed on the pile.

Withdrawal of the two outer blocks in each foil channel is facilitated by a coupling mechanism.

Five source positions permit operation with reduced harmonics.

The neutron distribution in the pile was proven to be symmetric by horizontal and vertical traverses.

By means of a diffusion length measurement, which gave an "L” of 54.5 ± 2 cm, and a Fermi Age measurement, which gave a "r” of 357 ± 5 cm², the parameters of the pile were shown to be in good agreement with published data on graphite.