The spectroscopy of trans-lead nuclei, e.g. actinide nuclei, produced in fusion evaporation reactions is hampered by the presence of a large fission background. A “filter” or “tag” is required to separate the γ rays of the evaporation residues from those of the fission products and other sources of background. There are several, complementary approaches to meet this requirement, including the d...

A new experimental station at ESRF beamline ID20 is presented which allows magnetic and resonant X-ray scattering experiments in the energy range 3-25 keV to be performed under extreme conditions. High magnetic field up to 10 T, high pressure up to 30 kbar combined with low temperatures down to 1.5 K are available and experiments can be performed at the M-edges of actinide elements, L-edges of ...

A new system for spin resolved photoelectron spectroscopy and bremsstrahlung isochromat spectroscopy has been built and commissioned at Lawrence Livermore National Laboratory for the investigation of the electronic structure of the actinides. Actinide materials are very toxic and radioactive and therefore cannot be brought to most general user facilities for spectroscopic studies. The technical...

In continuing to examine the interaction of actinide-ligand bonds with soft donor ligands, a comparative investigation phosphorus and arsenic was conducted. A reaction (C5Me5)2AnMe2, An = Th, U, 2 equiv H2AsMes, Mes 2,4,6-Me3C6H2, forms primary bis(arsenido) complexes, (C5Me5)2An[As(H)Mes]2. Both exhibit thermal instability at room temperature, leading elimination H2, formation diarsenido speci...

The neutronic performance of small size critical dedicated burners is investigated here according to the type of recycling performed (MA supply alone or together with some fissile element), the nature of the possible fissile supply (Pu, enriched U, U bred from Th), the coolant type (sodium or lead). The main neutronic parameters are given, such as reactivity coefficients, together with mass bal...

An analytic, parameter-free (up to overall scale factors) solution of the Bohr Hamiltonian involving axially symmetric quadrupole and octupole deformations, as well as an infinite well potential, is obtained, after separating variables in a way reminiscent of the Variable Moment of Inertia (VMI) concept. Normalized spectra and B(EL) ratios are found to agree with experimental data for Ra and Th...