Measurement of the spin and temperature dependence of ddµ molecule formation rate in solid and liquid deuterium

The ddµ molecule formation rate is experimentally measured for the two hyperfine states of the dµ-atom in the temperature range of 5–30 K. Results are consistent with a preliminary measurement by the TRIUMF group and contradict theoretical predictions. The work has been performed on the JINR phasotron (Dubna).     

On the Simplest Topologically Transitive Skew Products in the Plane

In this paper, we obtain (sufficient) conditions under which the set of periodic points of the topologically transitive skew product of mappings of an interval is dense in the phase space of the dynamical system considered.     

Axisymmetric Electric Waves of Periodic Waveguide Systems for Relativistic Microwave Electronics

We consider the use of one-dimensional integral equations of the second kind for calculation of axisymmetric waves in hollow and open periodic axisymmetric waveguide systems. Methods of discriminating between the fundamental and additional spectra of the problem are proposed. It is shown that the applicability range of this method can be extended considerably. In particular, a special transformation of the integration variable permits one to include waveguides with nonsmooth wall profiles in the applicability range of the method.     

Transition processes in the novel method of the muon catalysis investigation

The problem of modifying the interpretation of the results to be obtained with the novel method of muon catalysis investigation to take the fast transition processes into account is first considered. The results of exploring the process kinetics are compared with the ones found from the analysis of the appropriate Monte Carlo distributions. The calculation programs simulate both the kinetics and the registration system of the experiment which is now performed in the frame of the large international project TRITON. The main conclusion is that the multiplicity distribution of the fusion neutrons is “invariant” under any assumptions of the fast transition stage. This revised version was published online in July 2006 with corrections to the Cover Date.     

Coincidence of the sets of minimal and irreducible join graphs over primary structure of algebraic Bayesian networks

An algebraic Bayesian network (ABN) is a probabilistic-logic graphical model of bases of knowledge patterns with uncertainty. A primary structure of an ABN is a set of knowledge patterns, that are ideals of conjunctions of positive literals except the empty conjunction endowed with scalar or interval probability estimates. A secondary ABN structure is represented by a graph constructed over the primary structure, which is called a join graph. From the point of view of learning of a global ABN structure, of interest are join graphs with the minimum number of edges and irreducible join graphs. A theorem on the coincidence of the sets of minimal and irreducible join graphs over the same primary structure is proved. A greedy algorithm constructing an arbitrary minimal join graph from a given primary structure is described. A theorem expressing the number of edges in a minimal join graph as the sum of the ranks of the incidence matrices of strong restrictions of a maximal join graph minus the number of significant weights is stated and proved. A generalized graph of maximal knowledge patterns (GGMKP) is a graph with the same vertex set as the join graph which is not subject to any constraints concerning the possibility of joining two vertices by an edge. It is proved that the pair consisting of the edge set of a maximal GGMKP and the set of all subsets of this graph such that the subtraction of any such subset from the maximal GGMKP yields an edge of the join graph on the same vertex set is a matroid.     

Measurement of the Temperature Dependence of the ddμ-Molecule Formation Rate in Dense Deuterium at Temperatures 300–800 K

Muon catalyzed fusion in deuterium was studied by the MCF collaboration at JINR phasotron. The measurements were carried out with a high-pressure deuterium target at the JINR phasotron in the temperature range 300–800 K at densities ≃0.5 LHD. The first experimental results for ddμ-molecule formation rate λ _ddμ in the temperature range 400–800 K with deuterium density 0.5 LHD are presented. This revised version was published online in August 2006 with corrections to the Cover Date.     

Resonant ddµ-molecule formation in solid deuterium

The resonant ddµ-molecule formation process in solid deuterium is considered. It is shown that the rate of this process does not depend on temperature and is estimated to be _ddµ3µs^–1.     

Measurement of the temperature dependence of the ddμ molecule formation rate in dense deuterium at temperatures of 85–790 K

Muon catalyzed fusion (MCF) in deuterium was studied by the MCF collaboration on the Joint Institute for Nuclear Research Phasotron. The measurements were carried out with a high-pressure deuterium target in the temperature range 85–790 K at densities of about 0.5 and 0.8 of the liquid hydrogen density. The first experimental results for the ddμ molecule formation rate λ _ddμ in the temperature range 400–790 K with a deuterium density of about 0.5 of the liquid hydrogen density are presented.     

Experimental detection and investigation of muon catalyzed fusion of deuterium and tritium

Measurement of the neutron yield of the reaction $\text{dt}\text{μ →}{}^4\text{He}\text{+ μ}{}^{\mathrm{?}}\text{+ 17.6}\text{MeV}$, induced by negative muons in a mixture of gaseous D₂ and T₂, has shown that the rate of muon transfer from deuterium to tritium is λ_dt = (2.7 ± 0.9) × 10⁸s^?1 and that the lower limit of the formation rate of dt_μ molecules is λ_dtμ > 10⁸s^?1.     

Radiative and non-Radiative Fusion in Muonic Molecules

Considerable efforts in μCF studies (since [1]) were aimed at observation of various fusion processes. The impact of these studies on the understanding of properties of the lightest nuclei, the dynamics of low-energy fusion reactions and the Coulomb three-body system structure are reviewed. Unsolved theoretical and experimental problems are summarized. This revised version was published online in August 2006 with corrections to the Cover Date.