Baldacchini G, Grassano U M, Tanga A
C.N.E.N.-Centro di Frascati, Frascati, Italy.
Rev Sci Instrum. 1978 May;49(5):677. doi: 10.1063/1.1135484.
A small residual birefringence producing a retardation of 0.05 rad has been measured in silica windows mounted in a liquid helium cryostat. The effect is due to a uniaxial stress on the windows induced by the pressure difference between the helium reservoir and the vacuum jacket.