Standardization and photon emission probabilities in the decay of 237Np/233Pa

Theoretical study on K , L , and M X-ray transition energies and rates of neptunium and its ions

“…In these calculations, the radial wavefunctions have been obtained by solving the Dirac equations in the Thomas-Fermi potential, followed by screened hydrogenic functions; good starting wavefunctions are provided for the self-consistency procedure, which eventually helps overcoming convergence problems or simply reduces the number of iterations needed for a given set of configurations. Here, we have the ground configurations of each ion as follows: 2 , and [Rn]5f for Np ions with the charge states 1+ to 6+, respectively. The extended optimal level (EOL) scheme [40] is used to determine the initial and final state wavefunctions involved, separately.…”

“…The long-lived nuclide 237 Np is produced in a nuclear reactor when 235 U or 238 U interact with thermal or fast neutrons; it is one of the most important radiative hazards in the nuclear fuel cycle. [1][2][3][4] Its basic nuclear properties are well known, however, the electronic properties are still a subject of intense debate, largely due to the rich and peculiar phenomenology that they display [5,6] and the complicated electronic structure of the 5f state. [7] On the one hand, the experiments are extremely expensive and difficult to perform due to the toxic and radioactive nature.…”

The uncertainty of counting at a defined solid angle

“…The uncertainty of counting at a defined solid angle by several institutes, including IRMM (formerly CBNM) [8,9], LRL [10], NIST [11], ANL [12], CIEMAT [13,14], LNE-LNHB [15,16] and PTB [17]. New set-ups have recently been constructed in TAEK (Turkey) and NPL (UK), inspired by the IRMM model.…”

“…In a very simple design used e.g. at PTB [17], the source and diaphragm planes are connected by metal distance rods. This distance can be determined in an SI-tracable manner by comparing it with a stack of gauge blocks of similar height, using a height gauge with digital or dial readout.…”

“…IRMM uses a segmented design with source chamber, distance tube and diaphragm fitting together on smoothly connecting flanges. The distance between diaphragm and a reference plate in the source holder can be measured directly or calculated from the sum of the heights of the individual components with an accuracy of about (5)(6)(7)(8)(9)(10)(11)(12)(13)(14)(15)(16)(17)(18)(19)(20) µm. The distance seems unaffected by vacuum pumping.…”