Посилання:Testing critical point universality along the l - line / J.A. Nissen, D.R. Swanson, Z.K. Geng,J.A. Lipa, V. Dohm, U.E. Israelsson, M.J. DiPirro // Физика низких температур. — 1998. — Т. 24, № 2. — С. 122-126. — Бібліогр.: 22 назв. — англ.
Підтримка:We wish to thank the Office of Life and Microgravity Science and Applications of NASA for its
support with contract JPL 960613.
We are currently building a prototype for a new test of critical-point universality at the lambda
transition in ⁴He, which is to be performed in microgravity conditions. The flight experiment will
measure the second-sound velocity as a function of temperature at pressures from 1 to 30 bars in the
region close to the lambda line. The critical exponents and other parameters characterizing the behavior
of the superfluid density will be determined from the measurements. The microgravity measurements
wdl be quite extensive, probably taking 30 days to complete. In addition to the superfluid density, some
measurements of the specific heat will be made using the low-g simulator at the Jet Propulsion
Laboratory. The results of the superfluid density and specific heat measurements will be used to compare
the asymptotic exponents and other universal aspects of the superfluid density with the theoretical
predictions currently established by renormalization group techniques.