Japanese hadron facility plans and future μSR

The proposed next major science project in Japan, the high intensity 1 GeV proton accelerator with unique beam characteristics, is described here. It will supply a proton beam of more than 100 μA in either de mode or sharply pulsed mode (down to 10 ns), using a specially designed time structure conversion ring. The beam will be used for keV μ⁺ generation at the production target, MeV surface μ⁺ production and 10 MeV decay μ⁺ and μ⁻ production, as well as a possible slow μ⁻ production. All of these unique muon beams will be developed for the next generation of μSR experiments. With the development of the keV μ⁺ source particularly in mind, a pilot station is now under construction at UT-MSL/KEK. Possible new μSR experiments are also reviewed.     

Phase behaviour of colloid-polymer mixtures

Summary We review the phase behaviour of mixtures of colloids and non-adsorbing polymers. The exclusion of polymer molecules from overlapping ?depletion zones? between two neighbouring colloidal particles results in an unbalanced osmotic pressure pushing the particles together. This depletion potential is separately tunable in range and depth. Theory predicts that the resulting phase behaviour is sensitive to ξ=r _g/R, the ratio of the radius of gyration of a polymer molecule, to the radius of the colloid. At large ξ, a stable colloidalliquid phase becomes possible. This has been confirmed by recent experiments. The formation of non-equilibrium ?transient gel? states when the size ratio is small (≈0.08) is also introduced briefly. Paper presented at the I International Conference on Scaling Concepts and Complex Fluids, Copanello, Italy, July 4–8, 1994.     

Holographic image subtraction using a polarization technique

A holographic image subtraction technique is proposed. The vector nature of light is utilized in introducing a phase difference of π between the two reconstructed object waves. The experimental results are also presented.     

Properties of matrix-assisted laser desorption. Measurements with a time-to-digital converter.

Some properties of matrix-assisted laser desorption have been studied using single-ion-counting methods and a time-to-digital converter. The methods allow examination of the process for irradiances near the reported threshold for observation with a transient recorder. All measurements were made using bovine insulin as a test compound. We present direct evidence that an irradiance threshold near 10(6) W cm-2 exists for ion production, and that the process is a collective effect, either involving a large number of molecular ions (approximately 10(4) in a successful event or none at all. Above the threshold, the yield is found to scale with a high power (4th to 6th) of the irradiance. Measurements of initial velocity distributions indicate an axial velocity spread corresponding to approximately 50 eV and a radial velocity spread corresponding to approximately 2.4 eV. Thus the ejection or extraction mechanism appears to be strongly asymmetric.     

Synthesis of Phosphocapped Derivatives of β-Cyclodextrin

Russian Journal of General Chemistry -     

Observation of Substitutional Fe in CEMS Measurements on Synthetic CVD Diamond

Hyperfine Interactions - Conversion electron Mössbauer spectroscopy measurements have been made on a diamond sample synthesized by chemical vapour deposition. The sample was implanted with 70...     

Mean-value theorems and the nonoscillatory nature of solutions of partial differential equations in the spaces En and Pn

Analogs of the mean-value theorem are obtained for the Poisson equation with the Laplace-Beltrami operator in Euclidean and spherical spaces.Translated from Ukrainskii Matematicheskii Zhurnal, Vol. 44, No. 11, pp. 1477–1483, November, 1992.     

Study of the surface electromigration of In on Si(111) surfaces by the use of micro-electron-beams

The surface electromigration (SE) of ultrathin In films on Si(111)4 × 1-In surfaces has been investigated using experimental techniques based on μ-electron beams. On the basis of the finding that the SE velocity enhances as the strength of the electrostatic field (EF) fed through the substrate enhances, it is strongly suggested that the driving force of SE is an EF rather than a DC current fed through the substrate. It is found that a patch of ultrathin In film changes to an In patch of 1 × 1 periodicity during SE which is accompanied by spotty parts (named fine-polygons) at both the cathode and anode sides of the In patch. It is found that the fine-polygons are created at the cathode side and are stationary but grow in size to be eventually incorporated into the In-patch. A few In-islands are found on the cathode side of the In-patch and they show no translation but cycles of appearance, growth, decay, and disappearance during SE, by which mass-transportation is achieved. A plausible microscopic model for the SE is presented based on these findings.