QFS2016 Book of Abstracts

Abstracts

P4.18 Measurement of the complex permittivity of liquid He-4 in millimeters wave range by ”whispering gallery” mode resonator A.V. Smorodin(1), A.S. Rybalko(2) and D. Konstantinov(1). 1) Okinawa Institute of Science and Technology, Tancha 1919-1, Okinawa 904-0412, Japan 2) B.Verkin Institute for Low Temperature Physics and Engineering, Prospekt Nauky 47, Kharkiv 61103, Ukraine We report an experimental study of electrical properties of liquid helium 4 in temperature range 1.2-3 K. The complex permittivity of He4 was determined using a ”whispering gallery” resonator. Using the resonant perturbation method the complex permittivity of liquid He4 is extracted. Our result is consistent with theoretical and experimental works by other authors. We also discuss effect of doubling of the ”whispering gallery” modes propagating in the cavity. P4.19 Adiabatic melting experiment: status and prospects. A.P. Sebedash*, J.T. Touriniemi Aalto University, School of Science, Applied Physics Department. PO BOX 15100, 00076 AALTO, FINLAND *P.L. Kapitza Institute for Physical Problems, RAS, ul. Kosygina 2, Moscow, 119334, Russia We describe our ongoing experiment, aiming to cool saturated helium mixtures to ultra-low temperatures, into tens of microKelvins regime. Previously we demonstrated physical principle of cooling at temperatures well below of superfluid transition of concentrated phase, pure 3 He (JLTP,81, p.725 (2007)). We describe improvements made to protect system from irreversibility appearing owing to higher temperature surroundings, and to practical realization of the method. Results of testing different systems at low temperatures are presented and discussed.

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