Superconductive dipole magnets for big accelerators are subjected to enormous electro-magnetic force, when they are operated with high field such as 10 Tesla. They should be constructed by means of superconductive cables, which have high Young's modulus, to obtain good performance. To develop such cables we measured the Young's moduli of cables for practical use of accelerator magnets. They are monolithic and compacted strand cables. We measured also Young's moduli of monolithic copper and brass cables for comparison. The obtained data showed the Young's moduli of 35 and 15GPa for the monolithic and compacted strand cables, respectively.
The steady state heat flux and the related temperature profiles in pressurized superfluid helium II are calculated using the universal Gorter-Mellink equation proposed by Soloski et al. The results are in good agreement with the data obtained in this study within an experimental error.
The effects of pressure on heat transfer from a horizontal copper surface immersed in pressurized He I are experimentaly investigated. Heat transfer surface is 0.02m in diameter. The pressure is varied from 0.047MPa to 1.1MPa and helium temperature is varied from 3.0K to 5.0K. The data obtained are divided into two heat transfer regions, the subcooled heat transfer region and supercritical heat transfer region. Heat transfer in subcooled liquid helium are correlated with a modified Rohsenow equation based on saturation temperature difference. Peak nucleate boiling heat fluxes obtained in subcooled helium increase with subcooling and show two different slope in large subcooling. Heat transfer in liquid helium pressurized above critical pressure show a good agreement with a equation predicted from heat transfer in ordinary liquid.