Toshiyuki Misu

Deformed Nuclear Halos

Deformation properties of weakly bound nuclei are discussed in the deformed single-particle model. It is demonstrated that in the limit of a very small binding energy the valence particles in specific orbitals, characterized by a very small projection of single-particle angular momentum onto the symmetry axis of a nucleus, can give rise to the halo structure which is completely decoupled from the rest of the system. The quadrupole deformation of the resulting halo is completely determined by the intrinsic structure of a weakly bound orbital, irrespective of the shape of the core.

Symmetry Breaking and Bifurcations in the Periodic Orbit Theory. I: Elliptic Billiard

We derive an analytical trace formula for the level density of the two-dimensional elliptic billiard using an improved stationary phase method. The result is a continuous function of the deformation parameter (eccentricity) through all bifurcation points of the short diameter orbit and its repetitions, and possesses the correct limit of the circular billiard at zero eccentricity. Away from the circular limit and the bifurcations, it reduces to the usual (extended) Gutzwiller trace formula which for the leading-order families of periodic orbits is identical to the result of Berry and Tabor. We show that the circular disk limit of the diameter-orbit contribution is also reached through contributions from closed (periodic and non-periodic) orbits of hyperbolic type with an even number of reflections from the boundary. We obtain the Maslov indices depending on deformation and energy in terms of the phases of the complex error and Airy functions. We find enhancement of the amplitudes near the common bifurcation points of both short-diameter and hyperbolic orbits. The calculated semiclassical level densities and shell energies are in good agreement with the quantum mechanical ones.We derive an analytical trace formula for the level density of the two-dimensional elliptic billiard using an improved stationary phase method. The result is a continuous function of the deformation parameter (eccentricity) through all bifurcation points of the short diameter orbit and its repetitions, and possesses the correct limit of the circular billiard at zero eccentricity. Away from the circular limit and the bifurcations, it reduces to the usual (extended) Gutzwiller trace formula which for the leading-order families of periodic orbits is identical to the result of Berry and Tabor. We show that the circular disk limit of the diameter-orbit contribution is also reached through contributions from closed (periodic and non-periodic) orbits of hyperbolic type with an even number of reflections from the boundary. We obtain the Maslov indices depending on deformation and energy in terms of the phases of the complex error and Airy functions. We find enhancement of the amplitudes near the common bifurcation points of both short-diameter and hyperbolic orbits. The calculated semiclassical level densities and shell energies are in good agreement with the quantum mechanical ones.

Doctorate Holders’ Labor Market and Mobility: The Academic Career as the First Choice

Doctoral graduates account for a relatively small proportion of the overall population but their importance is widely recognised (OECD 2010). Having benefitted from highly specialised research training and produced an original contribution to science, doctorate holders are expected to play a key role in the knowledge economy as they stand in a position to drive forward advances in science, technology and knowledge about society. Evidence on the careers of doctorate holders (CDH) and their contribution to science, innovation and the economy is of high relevance not only to policy decision makers and governments who finance the training of this group of individuals and support their integration in the innovation system; but also to prospective employers in search of specific skills for their workforce; and the individuals themselves who consider whether to pursue doctorate studies and proceed with research or unrelated careers. This paper provides an overview of the key statistical and analytical findings that draw on data from the second international CDH data collection conducted in 2010, as well as some complementary sources. Box 1 provides further details on this project.

Domestic and International Destinations of Japan’s Doctorate Holders

In a knowledge-based economy with increasing R&D investment, the success of innovation relies on nurturing and securing highly trained and skilled talents within a global domain. Accordingly, the number of researchers has increased from 6.6 per 1000 employees in 1999 to 7.6 per 1000 in 2009 in the OECD area, and more new doctorate holders have been produced in the same decade (OECD 2011). The increase in the production of highly educated human resources in science and technology reflects concerns about scientific labor force shortages that were predicted for several OECD member countries in the early 1990s based on assumptions of increasing future demand for engineers and scientists and declining student interest in science and engineering (OECD 1991).

Broadband “in-series multistation” rf cavity with low voltage standing wave ratio

A configuration for an untuned broadband rf cavity with a low-voltage standing wave ratio (VSWR) is proposed. Although an untuned broadband cavity is currently implemented by loading magnetic alloy (MA) cores, the VSWR of such a cavity is expected to be no less than approximately 2.0 in the operational frequencies sweeping by a factor of about 10. A type of rf cavity, “in-series multistation” cavity, described here can cover a much broader frequency range sweeping by a factor of 20, while keeping the VSWR value below 1.2. The system consists of multiple stations, each of which is loaded with low-Q high-permeability MA cores. A “bench” test circuit was built and successfully tested.

Development of Co-Based Amorphous Core for Untuned Broadband RF Cavity

We have developed a cobalt-based amorphous core as a new magnetic-alloy (MA) core for the loaded RF cavity. Because of its permeability found to be approximately twice as high as that of FINEMET, this MA core is an excellent candidate for constructing a compact broadband RF cavity with less power consumption. In this report, we present our recent studies of the Co-based amorphous core’s physical properties, performance, and development.