project title: Design of a New Optical Cell for Studies of 3He Crystals in a Magnetic Field
project leader: Prof. George Pickett and Dr. Viktor Tsepelin
access given (in days): 91
access used (in days): 86
local host: Dr. Harry Alles
home institution: Lancaster University, Dept. of Physics
country of institution: UK
starting date (yyyy-mm-dd): 2005-08-01
Dr. Viktor Tsepelin is a junior scientist working in Lancaster University. His research interests cover studies of both quantum fluids and quantum solids. In the low temperature laboratory of Lancaster University he is able to conduct his superfluid 3He studies. In this project, he is starting a new line of quantum solid studies at high magnetic fields, which he is not able to undertake in Lancaster. The high field experiment requires several improvements in the optical nuclear demagnetization refrigerator, located in the Low Temperature Laboratory, before it can be used for the planned experiments. In this project, the initial improvements of the refrigerator and the design of the new optical cell will be made. This difficult project is a collaborative effort with Leiden University and Helsinki University of Technology.
Dr. Tsepelin worked in the ULTI facility altogether 31 days during the period 1.4.2006-31.3.2007. He was mainly involved in designing of a new optical cell for the studies of the superfluid-solid interface of 3He at ultra low temperatures. As the first step, he worked out the principal scheme of the experimental cell. That was not a very trivial task as in addition to cooling of the superfluid-solid interface of 3He below 0.3 mK we would also like to apply a magnetic field of the order of 0.5 T to the sample. To meet these requirements, the study of different materials (copper, silver and coined silver) was then initiated in order to find out which material (or which combination of them) suites best for our needs. The results of these measurements will be the main body of the Master Thesis of Matti Manninen, an undegraduate student of the Interface group, who has been carrying out these studies since the beginning of 2007.