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

The authors combine modern theoretical calculations with evaluated selected experimental data to produce a comprehensive data resource of K- and L-x-ray transition and absorption edge energies for all of the elements from neon to fermium. The theoretical and experimental components of this work are the result of programs of parallel development extending over more than 20 years. At each of several progressively more refined comparisons, it was possible to identify theoretical components whose systematic improvement then led to the next level of refinement in comparisons with an increasingly robust experimental reference data set. We have now reached a certain practical limit in what can be undertaken with reasonable levels of theoretical effort. This limit is not very different from the practical level of accuracy that can be meaningfully associated with the experimental data. For the more prominent diagram lines, experiment and theory are concordant with a zero-centered distribution of residuals whose statistical metrics allow the uncertainties to be estimated. For the light elements $(Zl20)$ and the very heavy elements $(Zg90)$ there are significant difficulties, as is also the case for a few isolated elements and transitions for $20lZl90.$ Overall, the results reported here represent improvements over previously available data compilations not only because of their scope but also because of their attempt to offer internal metrics of the database accuracy. The identified regions of difficulty are areas where further experimental work may be directed to see if there may remain theoretical issues that are still unresolved.

X-ray transition energies: new approach to a comprehensive evaluation

Global distribution of Pu isotopes and 237Np.

Nuclear-charge distribution and delayed-neutron yields for thermal-neutron-induced fission of 235U, 233U, and 239Pu and for spontaneous fission of 252Cf

The November 1, 1952 thermonuclear explosion ("Mike") produced all of the uranium isotopes ${\mathrm{U}}^{239}$, ${\mathrm{U}}^{240}$,...${\mathrm{U}}^{255}$ through multiple neutron capture by ${\mathrm{U}}^{238}$. The long-lived products of successive ${\ensuremath{\beta}}^{\ensuremath{-}}$ decays from these isotopes were measured mass spectrometrically and radiometrically. The logarithms of the abundances decline smoothly with increasing mass number; the even-mass abundances slightly exceed the geometric mean of adjacent odd-mass abundances. Some nuclear properties of neutron-rich heavy nuclides, not subject to ordinary investigation are inferred.

Heavy Isotope Abundances in Mike Thermonuclear Device

Xenon and fluorine combine readily. Xenon tetrafluoride is a colorless crystalline material, stable at room remperature. The existence of at least one other fluoride and two oxyfluorides has been demonstrated. The heaviest "inert gas," radon, also reacts with fluorine, yielding a compound less volatile than xenon tetrafluoride.

https://science.sciencemag.org/content/sci/138/3537/136.full.pdf

Fluorine Compounds of Xenon and Radon.

Author(s): Ghiorso, A.; Thompson, S.G.; Higgins, G.H.; Seaborg, G.T.; Studier, M.H.; Fields, P.R.; Fried, S.M.; Diamond, H.; Mech, J.F.; Pyle, G.L.; Huizenga, J.R.; Hirsch, A.; Manning, W.M.; Browne, C.I.; Smith, H.L.; Spence, R.W.

/pdf/new-elements-einsteinium-and-fermium-atomic-numbers-99-and-4ulyyj7mu4.pdf

New Elements Einsteinium and Fermium, Atomic Numbers 99 and 100

Decay Properties of Plutonium-244, and Comments on its Existence in Nature

The spontaneous fission neutron spectrum of ${\mathrm{Cf}}^{252}$ from 0.2 to 7.0 Mev has been measured. Time-of-flight techniques were employed to determine the lower energy portion of the spectrum while proton recoils in emulsions were used to study the higher energy neutrons. The measured neutron spectrum is, within the experimental accuracy, described by the empirical relation $N(E)\ensuremath{\propto}\mathrm{exp}[\ensuremath{-}0.88E(\mathrm{Mev})]sinh{[2.0E(\mathrm{Mev})]}^{\frac{1}{2}}$, where $N(E)$ is the number of neutrons of energy $E$ per unit energy interval. The experimental results are compared with the theoretically determined ${\mathrm{Cf}}^{252}$ fission neutron spectrum.

P. R. Fields

Papers

Heavy Isotope Abundances in Mike Thermonuclear Device

Fluorine Compounds of Xenon and Radon.

New Elements Einsteinium and Fermium, Atomic Numbers 99 and 100

Decay Properties of Plutonium-244, and Comments on its Existence in Nature

Spontaneous Fission Neutron Spectrum of Cf 252