18 Matching Results

Search Results

Advanced search parameters have been applied.

Calculations of the ground state energy and exchange integrals of crystalline $sup 3$He

Description: Thesis. The variational equation is derived and discussed using Jastrowtype wave functions, which are a product of pair wave functions, as the trail wave function. The various approximations used in simplifying the variational equations so as to obtain a form that is possible to solve numerically are discussed also. A Monte Carlo calculation is described using the wave function obtained. Exchange in /sup 3/He is discussed. (MHR)
Date: July 1, 1973
Creator: Lim, W L
Partner: UNT Libraries Government Documents Department

Helium II film transfer rates for solid-argon beakers

Description: Helium II film transfer rates were measured for filling and for emptying beakers of solid argon. Liquid argon was frozen slowly in a mold which was later removed, leaving free-standing, transparent solid-argon beakers. The beakers used were of 3 mm ID, 5 mm OD, and 3.5 cm in height. Experiments were carried out in the temperature range 1.45 to 2.0 K. The dependence of the transfer rate 0 (cm/sup 3//sec-cm of circumference) on the difference between the inner and outer helium levels Z, height of the beaker lip above the level of the liquid source H, and temperature, were studied. The transfer rates were lower than those observed with glass beakers, in agreement with theory. For beaker fillings with a level difference of l mm and at a temperature of 1.66 K, the measured transfer rates may be described by the relation sigma = 4.8 H/sup -0.21 x l0/sup -5/ cm/sup 2// sec, where H is in cm. (auth)
Date: January 1, 1973
Creator: Milbrodt, T.O.
Partner: UNT Libraries Government Documents Department