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[en] A demonstration of a theorem which concerns the Dirichlet boundary conditions and the characteristics in the classical limit of resonance and scattering is given: mathematical values (convergent series) of the eigenvalue and the tunneling parameter

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[en] The PROTEUS zero power reactor at the Paul Scherrer Institute (PSI) in Switzerland achieved first criticality in 1968 and since then has been operated as an experimental tool for reactor physics research on test lattices representative of a wide range of reactor concepts. Reactor design codes and their associated data libraries are validated on the basis of the experimental results obtained. PROTEUS is normally configured as a driven system, in which a subcritical test zone is made critical by the surrounding driver zones. The advantages of driven systems can be summarized as follows: - Smaller amount of test fuel is required; - Large range of test zone conditions (including k_∞ < 1 states) can be investigated by changes in the driver loading alone, thus avoiding undesirable perturbations to the test zone which would influence the measurement conditions and thus affect the interpretability of the results; - Necessary reactor control and instrumentation equipment (usually perturbing from the experimental viewpoint) can be located in the outer driver regions, thereby avoiding disturbance of the test lattice

[en] For a class of Schroedinger operators, with potentials having minima embedded in the continuum of the spectrum and non-trapping tails, we show the existence of shape-resonance exponentially close to the real axis as n → ν. The resonant energies are given by a convergent perturbation expansion in powers of a parameter exhibiting the expected exponentially small behaviour for tunneling

[en] Experimental investigations in the zero-power reactor PROTEUS at PSI address questions related to the physics and safety of both current-day and advanced reactor systems. Till now, the gas-cooled fast reactor, the light water high conversion reactor and the high temperature pebble-bed reactor (with low enriched uranium fuel) have been investigated. A new experimental programme is planned. This programme is related to the investigation of highly heterogeneous BWR fuel assemblies and the validation of innovative LWR core concepts for Pu-incineration

[en] The electronic part of diatomic molecular Hamiltonians is analyzed as a function of the internuclear distance, x. Analyticity is proven outside x not = 0 of eigenvalues in the discrete spectrum and differentiability up to second order for the associated projection operators. Furthermore, it is shown that for large internuclear distances they converge to eigenvalues and eigenprojectors of the separated atoms. 17 references

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[en] The zero-power reactor, PROTEUS, has been used over the years for physics investigations concerning various types of advanced systems, namely gas-cooled fast reactors (GCFRs) in the seventies, light water high-conversion reactors (LWHCR) in the eighties and, currently, low-enriched-uranium high-temperature reactors (LEU-HTRs). The wide range of test neutron spectra cover underlines the versatility of the facility, the safety and operational limits for which have largely remained unaltered during the different experimental programs. This paper reviews the scope of the various PROTEUS investigations and includes evaluations of some of the most recent experiments