Testing critical point universality along the l - line

• Published in: Физика низких температур
• Date: 1998
• Main Authors: Nissen, J.A., Swanson, D.R., Geng, Z.K., Lipa, J.A., Dohm, V., Israelsson, U.E., DiPirro, M.J.
• Format: Article
• Language: English
• Published: Фізико-технічний інститут низьких температур ім. Б.І. Вєркіна НАН України 1998
• Subjects: Специальный выпуск International Workshop on Low Temperature Microgravity Physics
• Online Access: https://nasplib.isofts.kiev.ua/handle/123456789/176367
• Journal Title: Digital Library of Periodicals of National Academy of Sciences of Ukraine
• Cite this: 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.

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.