Alpha-decay half-life of 253Es in metallic Fe at temperatures between 4 K and 50 mK

It has been claimed recently that half-lives of radioactive nuclei embedded in metals would be significantly affected by electron screening provided by the metal. The effectwould further be strengthened at low temperatures. We have determined the half-life-of 253Es nuclei embedded in iron at temperatures between 4 K and 50 mK. Our results agree with the room temperature literature value within about 2% and show no dependence on temperature over a range of almost two orders of magnitude.status: publishe

Hyperfine field of einsteinium in iron and nuclear magnetic moment of 254Es

The angular distributions of γ rays and α particles from oriented 250Bk, 253,254Es, and 255Fm nuclei were investigated to extract hyperfine interaction information for these actinide impurities in an iron host lattice. The hyperfine field of einsteinium in iron was found to be |Bhf (EsFe|) = 396(32) T. With this value the magnetic moment of 254Es was then determined as |μ| = 4.35(41) μN.status: publishe

Combinatorial distance geometry in normed spaces

We survey problems and results from combinatorial geometry in normed spaces, concentrating on problems that involve distances. These include various properties of unit-distance graphs, minimum-distance graphs, diameter graphs, as well as minimum spanning trees and Steiner minimum trees. In particular, we discuss translative kissing (or Hadwiger) numbers, equilateral sets, and the Borsuk problem in normed spaces. We show how to use the angular measure of Peter Brass to prove various statements about Hadwiger and blocking numbers of convex bodies in the plane, including some new results. We also include some new results on thin cones and their application to distinct distances and other combinatorial problems for normed spaces