Aalto University, P.O. Box 11000, FI-00076 Aalto www.aalto.fi Author Juho Rysti Name of the doctoral dissertation Microscopic and Macroscopic Studies of Liquid and Solid Helium Mixtures Publisher School of Science Unit O.V. Lounasmaa Laboratory Series Aalto University publication series DOCTORAL DISSERTATIONS 110/2013 Field of research Engineering Physics, Physics Manuscript submitted 16 April ...

A time-dependent neutronics analysis for the HIBALL reactor is presented. The helium to dpa ratio in the ferritic steel structure is found to be sensitive to neutron spectrum softening. The microstructure calculations show that helium diffusivity is a sensitive function of vacancy accumulation from one pulse to the next. A strong coupling exists between the three components of damage: helium, v...

The substitution of helium for nitrogen in the inspired air has been advocated for two entirely different reasons. First, Sayers and Yant (1926) suggested that owing to the low solubility of helium its use in diving and other operations involving respiration under high pressure might reduce the incidence of caisson disease. Secondly, Barach (1934) suggested that the lesser mass of the helium mo...

A method is described for investigating the ionization produced in helium by collisions between quasi-stationary atoms—that is, atoms possessing only thermal velocities—and a beam of neutral helium atoms with kinetic energy less than 100 eV. Ionization is shown to begin when the kinetic energy of the bombarding atoms is twice as great as the minimum kinetic energy which electrons must possess i...

Positron scattering from helium has been historically limited to experiments with energy resolution of 0.5 eV or worse. A new apparatus has been developed that allows the investigation of scattering processes with an energy resolution as good as 30 meV, allowing new experimental insight into positron helium interactions. High resolution measurements of low energy scattering from helium will be ...

© 2009 American Institute of Physics, S-0031-9228-0910-020-0 Early research with liquid helium showed that it had remarkable new properties, especially below the so-called lambda transition near 2.2 K, where there is a sharp, narrow peak in the specific heat (see figure 1a). The liquid below the transition was named helium II to distinguish it from the liquid above the transition, called helium...

2S 0918–549 is a low-mass X-ray binary (LMXB) with a low optical to X-ray flux ratio. Probably it is an ultracompact binary with an orbital period shorter than 60 min. Such binaries cannot harbor hydrogen rich donor stars. As with other (sometimes confirmed) ultracompact LMXBs, 2S 0918–549 is observed to have a high neon-to-oxygen abundance ratio (Juett et al. 2001) which has been used to argue...