Measurement of formation rates of ddµ and pdµ mesic molecules in H/D-gas mixtures

The formation rates of muonic molecules pdµ and ddµ have been measured by means of a high-pressure ionization chamber at various deuterium concentrations in equilibrated and non-equilibrated H/D-gas mixtures at 200 and 300 K. The measurements were performed on the muon beam of the PNPI synchrocyclotron in 1986–1991. The low pdµ formation rate and its dependence on the type of mixture was discussed in Oxford, MCF-89. In detailed analysis it was found that the ddµ formation rate in an H/D gas mixture is lower than in pure deuterium. These measurements are of special interest in connection with the experiment being prepared at PSI.     

Muon catalyzed fusion in deuterium gas

We present the results of an experiment performed at PSI to investigate muon catalyzed fusion in pure deuterium gas of 5% density (LHD) at temperatures ranging from 28 K to 350 K. Using a new high pressure ionization chamber the reactions dd → n + ³He and dd → p+t were observed with 100% detection efficiency. The rates of dμd formation were measured with the absolute precision of 1% and the μd spin-flip rates with 0.5%. The temperature dependence of molecular formation and spin-flip rates display pronounced resonance structures. A preliminary fit based on the Vesman mechanism of resonant muonic molecule formation was carried out yielding a dd fusion rate of 3.5·10⁸ s^-1 and a hfs splitting energy of 24.3 meV, both in good agreement with the theory. This revised version was published online in August 2006 with corrections to the Cover Date.     

Formation of Pt/C catalysts on various carbon supports

Platinum catalysts with the active component content of 5–40 wt % on various carbon supports have been synthesized by the reductive hydrolysis of platinum chloro complexes. The degree of dispersion of the supported platinum decreases with an increasing weight percentage of the metal in the catalyst. The following mechanism of Pt/C catalyst formation is deduced from experimental data: H₂PtCl₆ adsorption on the support surface generates platinum nuclei, which then grow owing to the deposition of platinum ions under the action of an alkali and a reductant.