Predicting the influence of a p2-symmetric substrate on molecular self-organization with an interaction-site model

An interaction-site model can a priori predict molecular selforganisation on a new substrate in Monte Carlo simulations. This is experimentally confirmed with scanning tunnelling microscopy on Fre´chet dendrons of a pentacontane template. Local and global ordering motifs, inclusion molecules and a rotated unit cell are correctly predicted

Production of pulsed ultra slow muons and first mu SR experiments on thin metallic and magnetic films

At ISIS, RAL (UK) we have produced a pulsed ultra-slow muon beam (E less than or similar to 20eV) and performed the first mu SR experiments. Thanks to the pulsed feature, the implantation time is automatically determined and, by adjusting the final muon energy between similar to 8 keV and 20 eV, depth slicing experiments are possible down to monolayers distances. We report slicing experiments across a 20 nm copper film on quartz substrate with evidence for a 2 nm copper oxide surface layer. A preliminary experiment on a hexagonal cobalt film suggests the existence of muon precession in the local magnetic field. (C) 2000 Published by Elsevier Science B.V. All rights reserved

Pulsed laser spectroscopy in muonium and deuterium

The 1s-2s energy interval in the muonium (μ+e-) atom has been measured by Doppler-free two-photon laser spectroscopy. A value of 2 455 528 941.0(9.8) MHz has been obtained in good agreement with quantum electrodynamics (QED). The muon-electron mass ratio can be extracted and is found to be 296.768 38(17). The measurement may also be interpreted as a determination of the muon-electron charge ratio as - 1 - 1.1(2.1)·10-9. Corresponding measurements in deuterium using the same experimental setup confirmed the validity of the applied analysis procedure

Measurement of the 1s-2s energy interval in muonium

The 1s-2s interval has been measured in the muonium ({$\mu^+e^-$}) atom by Doppler-free two-photon laser spectroscopy. The frequency separation of the states was determined to be 2 455 528 941.0(9.8)~MHz in good agreement with quantum electrodynamics. The muon-electron mass ratio can be extracted and is found to be 206.768 38(17). The result may be interpreted as measurement of the muon-electron charge ratio as $-1- 1.1(2.1)\cdot 10^{-9}$