Industrial Surfaces Behaviour Related to the Adsorption and Desorption of Hydrogen at Cryogenic Temperature

The determination of the hydrogen adsorption capacity on different industrial surfaces has been carried out by measuring isothermal adsorption. First results show that the adsorption capacity is mainly determined by surface porosity. Therefore, the samples may be classified in two categories: smooth surfaces and porous surfaces. Thermal desorption spectra reveal two adsorption energy levels for hydrogen physisorbed on porous materials, but only a single one on smooth samples. The value of the lowest energy level seems to be independent on the substrate nature. The physisorption process studied at low coverage, well below a monolayer, shows that these two levels are not well defined but an energy distribution exists for each of them.The influences of the isotherm temperature and an annealing at 7 K of an adsorbed monolayer on hydrogen adsorption capacity have been studied

Status of ECR ion sources at JAERI

At the Takasaki site of Japan Atomic Energy Research Institute, four ECR ion sources were purchased or developed so far. This paper will report their performance, modification and status. The outlines for each source are as follows; 1. OCTOPUS purchased from IBA s.a. has been in use with a cyclotron since 1990. The gas feed system was modified to change gas species within 10 minutes to avoid impurity ions in the cocktail beam acceleration technique of the cyclotron. 2. ECR-18 with 18-GHz microwave has a solenoid coil between a pair of mirror coils to change mirror ratio in a wide range. A bump between mirror peaks in the original axial field distribution was removed by halving the solenoid length. The performance in generating high charge state ions was significantly improved as a result. 3. HYPERNANOGAN was purchased from PANTECHNIK s.a. and installed in the cyclotron system this year. Test operation was successfully made with generation of Ar, Pb and Ta ions. 4. MINI ECR is a full permanent magnet source with 10 GHz microwave. As a result of modifications for vacuum and the application of a bias probe, 40 microA of Ar4+ beam was obtained, for example. Using this source, a new technique was developed to vaporize very refractory materials into plasma by fluorinating them with SF6 plasma. The source is in use for a 400 kV ion implantor since last year

New Universality of Lyapunov Spectra in Hamiltonian Systems

A new universality of Lyapunov spectra {\lambda_i} is shown for Hamiltonian systems. The universality appears in middle energy regime and is different from another universality which can be reproduced by random matrices in the following two points. One is that the new universality appears in a limited range of large i/N rather than the whole range, where N is degrees of freedom. The other is Lyapunov spectra do not behave linearly while random matrices give linear behavior even on 3D lattice. Quadratic terms with smaller nonlinear terms of potential functions play an intrinsic role in the new universality.Comment: 19 pages, 16 Encapsulated Postscript figures, LaTeX (100 kb