At low excitation energies a "constant nuclear temperature" representation of nuclear-level densities is used, and at high excitation energies the regular Fermi gas formula is adopted. A method is ...

A composite nuclear-level density formula with shell corrections

https://iopscience.iop.org/article/10.1088/0034-4885/18/1/301/pdf

The Displacement of Atoms in Solids by Radiation

RIPL – Reference Input Parameter Library for Calculation of Nuclear Reactions and Nuclear Data Evaluations

Sequential separation of light rare-earth elements, thorium and uranium by miniaturized extraction chromatography: Application to isotopic analyses of silicate rocks

The effect of nitric acid concentration on the selectivity of a novel extraction chromatographic resin consisting of an octanol solution of 4,4′(5′)-bis(t-butyl-cyclohexano)-18-crown-6 sorbed on an inert polymeric support for strontium over a number of alkali, alkaline earth, and other metal cations was evaluated. The effect of macro quantities of selected elements on strontium retention by the resin was also examined. The resin is shown to exhibit excellent selectivity for strontium over nearly all of the test elements; only lead and tetravalent neptunium, polonium, and plutonium show significant affinity for the material. In addition, concentrations of calcium or sodium ion up to ∼ 0.1 M. are shown not to diminish the sorption of strontium appreciably. Several useful radiochemical separation schemes devised on the basis of the results obtained are described.

A novel strontium-selective extraction chromatographic resin*

The half-lives of 245Cm, 246Cm, 248Cm, 250Cf, 251Cf and 249Cf☆

ABEC™-5000, an aqueous biphasic extraction chromatography resin consisting of monomethylated polyethylene glycol (PEG)-5000 covalently bound to a polystyrene support, was investigated for its ability to remove pertechnetate from simulated Hanford tank wastes Retention of TcO4 − on the resin in batch mode from 2 and 4 M NaOH and from the waste simulants NCAW, SY-101, and SST, indicated that pertechnetate can be selectively removed from these solutions Column studies were conducted with 4 M NaOH and the NCAW simulant spiked with Na99mmTcO4 or Na95mMmTcO4 The columns can be easily stripped using water, thus concentrating the pertechnetate The effects of several matrix ions present in the Hanford tanks were investigated It was found that nitrite and nitrate lower the retention of TcO4 −, while citrate, carbonate, and aluminate enhance the retention It was also observed that raising the temperature from 25 °C to 40 °C has little effect on retention Radiation stability studies indicate that ABEC

Aqueous biphasic extraction chromatography (abec™): uptake of pertechnetate from simulated hanford tank wastes

The beta decay of ${\mathrm{Bk}}^{250}$ has been studied with a beta spectrometer. ${\mathrm{Bk}}^{250}$ has two beta groups: 725\ifmmode\pm\else\textpm\fi{}15 kev (89\ifmmode\pm\else\textpm\fi{}1% abundant) and 1760\ifmmode\pm\else\textpm\fi{}50 kev (11\ifmmode\pm\else\textpm\fi{}1% abundant). Conversion electron lines corresponding to 42.2, 98.2, 890, 930, 990, and 1032-kev transitions were observed and their intensities measured. The information obtained from crystal spectrometer singles and coincidence measurements was combined with beta spectrometer data to construct a decay scheme for ${\mathrm{Bk}}^{250}$ involving gamma vibrational levels in ${\mathrm{Cf}}^{250}$ analogous to those found in ${\mathrm{Pu}}^{238}$. The beta half-life of ${\mathrm{Bk}}^{250}$ is 193.3\ifmmode\pm\else\textpm\fi{}0.3 minutes. The electron capture partial half-life of ${\mathrm{Bk}}^{250}$ is estimated to be greater than 50 hours. The beta spectrum of ${\mathrm{Bk}}^{249}$ shows an allowed or first-forbidden transition with an end-point energy of 125\ifmmode\pm\else\textpm\fi{}2 kev.

Beta Decay of Bk 250 and Bk 249

Curium isotopes 246 and 247 from pile-irradiated plutonium

The degree of Interaction or compatibility of the neutral bifunctional extractant 0фD(lB)CMP0 with a diluent was determined by measuring the distribution ratio of the extractant between two phases. The distribution ratio, DCMPO, was highest in chloro-carbon and aromatic diluents with small molar volumes and lowest in normal paraffinic hydrocarbon diluents with large molar volumes. An approximate correlation between DCMPO in a variety of diluents and the solubility parameter (&#x1d6c5;) of the diluent was obtained using equations for regular solutions and b.delta;H2o =34.8. A much better correlation was obtained between DCMP0 find an empirical solution parameter. It was found that the distribution ratio of diisobutylcarbamoylmethylphosphine oxides increased by 3 orders of magnitude as the basicity of the phosphoryl group on the extractant was increased by the replacement of two phenyl substi-tutents on the phosphorus atom with two octyl groups The influence of TBP as a phase modifier in 0фD (iB)CMPO -dilu...

Herbert Diamond

Papers

The half-lives of 245Cm, 246Cm, 248Cm, 250Cf, 251Cf and 249Cf☆

Aqueous biphasic extraction chromatography (abec™): uptake of pertechnetate from simulated hanford tank wastes

Beta Decay of Bk 250 and Bk 249

Curium isotopes 246 and 247 from pile-irradiated plutonium

The influence op the diluent on the distribution behavior of octyl(phenyl)-n,n-diisobutylcarbamoylmethylph0sphine oxide*