Helium is the second most abundant element in the Universe after hydrogen. Considerable resources of helium-3 isotope (He3) are located mostly outside the Earth. He3 is very important for science and industry, especially for airport neutron detectors, lung tomography and helium dilution refrigerators. Besides, global warming is forcing the industry and governments to search for alternative energy sources, and He3 has the potential to be used as fuel in future nuclear fusion power plants. Unfortunately, the price of gaseous He3 has recently increased from $200 per liter to over $2750. The expected further increase in price and demands led us to present an analysis of the economic profitability for He3 separation process, which utilizes the properties of superfluid helium. This paper shows the arguments supporting the idea that extraction from natural sources is the only economically viable way of obtaining He3 isotope nowadays. The method could be relatively easily implemented into the production cycles of the low temperature natural gas purification plant.

The ${}^3$He isotope finds applications in many areas of science and industry, the most important of which are cryogenics, where ${}^3$He allows for achieving millikelvins in dilution refrigerators, and public security with ${}^3$He detectors of radioactive materials at airports and important buildings. ${}^3$He is also used in medicine for lung tomography. One of the most extraordinary future applications is the use of ${}^3$He in fusion reactors for clean energy. ${}^3$He is currently very expensive, with prices reaching USD 2750 for 1 liter of gas in normal conditions; thus, more effort is put into finding economically viable methods to acquire this isotope. The article shows research results of acquiring the ${}^3$He isotope from liquid helium by a quantum separation method with the use of entropy filters based on new carbon nanomaterials: purified multiwall carbon nanotubes (MWCNTs) and purified multiwall carbon nanotubes decorated with ZrO${}_2$ nanoparticles. MWCNTs were bundled and applied in the form of pressed tablets with fixed sizes. The research was conducted at the low-temperature region, where helium exhibits its quantum properties by undergoing a phase transition to the superfluid phase at the lambda temperature: T${}_{\lambda }$= 2.18 K. Entropy filters work below this temperature.

The development of new generation, highperformance devices, such as MRI scanners or high-energy accelerators, (may be attributed to the use of) Nb3Sn based superconducting (SC) magnets, which are characterized by their ability to produce much higher magnetic fields than the presently used NbTi-based magnets. Due to the wind-andreact technology of the production of Nb3Sn magnets, new methods and materials for the magnet coil electrical insulation are required. The proper design of SC magnets demands the characterization of thermal properties of the new insulation materials, inter alia, in superfluid helium conditions. This paper provides experimental data of the thermal conductivity and Kapitza resistance for S-glass fiber reinforced ceramic-epoxy (LARP type) electrical insulation, measured in pressurized (at 1 bar pressure) superfluid helium in a temperature range of 1.50-2.00 K.