Energy- and angle-differential neutron fluence measurements with superheated drop (bubble) detectors

D’Errico, Francesco; Matzke, M.; Siebert, Bernd

doi:10.1016/s0168-9002(01)01441-3

Cited by 11 publications

(4 citation statements)

References 18 publications

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“…All of the squarate bond distances and angles are consistent with those previously reported in the literature. 17 4 (M = Am, Cf; Am2, Cf2) crystallize in the centrosymmetric monoclinic space groups P2 1 /c (Cf2) and P2 1 /n (Am2) (Table 1). It should be noted that although these compounds are isostructural, Am2 can be satisfactorily solved only in space group P2 1 /n.…”

Section: ■ Results and Discussionmentioning

confidence: 99%

“…Understanding the chemical similarities and differences between the trivalent lanthanides and the later trivalent actinides (Pu and beyond) is of immense and continued interest. As both of these f-element series find widespread use in our daily livesfrom electronic, optical/lighting, and magnetic applications for the lanthanides to energy applications for the actinides and to fuel cells and medical applications for both seriesunderstanding the basic and applied chemistry of these elements is essential, yet challenging because of the radioactivity of the transplutonium elements. − Furthermore, many of the fundamental properties of these transplutonium elements have yet to be sufficiently explored. This lack of knowledge poses challenges related to nuclear energy and waste, separations, storage, and applied materials applications.…”

Section: Introductionmentioning

confidence: 99%

“…4 (M = Am, Cf; Am2, Cf2) Complexes Using KS Wave Functions at the PBE0/STO-TZP Level of Theory (All Energies Are Given in eV) pubs.acs.org/IC Article…”

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confidence: 99%

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Trivalent f-Element Squarates, Squarate-Oxalates, and Cationic Materials, and the Determination of the Nine-Coordinate Ionic Radius of Cf(III)

et al. 2020

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The synthesis, structure, and solid-state UV–vis–NIR spectroscopy of four new f-element squarates, M2(C4O4)3(H2O)4 (M = Eu, Am, Cf) and Sm(C4O4)(C4O3OH)(H2O)2·0.5H2O, four new cationic lanthanide squarate chlorides, [M4(C4O4)5(H2O)12]Cl2·5H2O (M = Eu, Dy, Ho Er), and two new actinide squarate oxalates, M2(C4O4)2(C2O4)(H2O)4 (M = Am, Cf), are presented. All of the metal centers are trivalent. Single-crystal X-ray diffraction analysis reveals that M2(C4O4)3(H2O)4 and Sm(C4O4)(C4O3OH)(H2O)2·0.5H2O have a two-dimensional sheet structure constructed from MO7(H2O)2 monocapped square-antiprismatic (coordination number (CN) = 9) metal centers and SmO6(H2O)2 square-antiprismatic (CN = 8) metal centers, respectively, whereas M2(C4O4)2(C2O4)(H2O)4 have a three-dimensional (3D) structure constructed from MO7(H2O)2 monocapped square-antiprismatic (CN = 9) metal centers. Additionally, the cationic framework materials [M4(C4O4)5(H2O)12]Cl2·5H2O have a 3D structure constructed from two crystallographically unique MO5(H2O)3 square-antiprismatic (CN = 8) metal centers. In these structures, the squarate ligands bind to the metal centers with varying coordination modes and denticities. The results of this study provide another example of the nonparallel chemistry between the lanthanides and transplutonium elements. From the crystallographic data for the isotypic series M2(C4O4)3(H2O)4 (M = La–Nd, Sm, Eu) and the linear regression fit to a plot of the unit cell volume as a function of the cube of the ionic radius, the nine-coordinate ionic radius of Cf 3+ was determined to be 1.127 ± 0.003 Å. Finally, computational analysis of the americium and californium complexes M2(C4O4)3(H2O)4 and M2(C4O4)2(C2O4)(H2O)4 reveals three important attributes: (i) the 5f orbitals are nonbonding in all cases, with the bonding differences occurring with the empty 6d orbitals; (ii) the Cf complexes exhibit more covalent character than their Am counterparts; and (iii) there is more covalent character in the squarate-oxalate complexes than in the squarate complexes.

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Section: ■ Results and Discussionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

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Trivalent f-Element Squarates, Squarate-Oxalates, and Cationic Materials, and the Determination of the Nine-Coordinate Ionic Radius of Cf(III)

et al. 2020

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“…However, even with the case for developing the fundamental chemistry of these elements being hindered, both berkelium and californium have important uses as targets for fusion reactions that yield SHEs such as tennessine ( Z= 117) and oganesson ( Z= 118), and perhaps even in preparing elements that are not currently known . In addition, while chemists often view the radioactive decay of actinides as a nuisance and hazard, the spontaneous fission of 252 Cf ( t 1/2 =2.6 y), and the resultant high flux of neutrons, has led to numerous applications in portable neutron activation analysis, for which it is in high demand in the petroleum and mining industries . Finally, during the Eisenhower administration substantial efforts were made to alter the course of the atomic era from one that developed horrifying weapons of mass destruction to methods for unifying humanity, that is, the “Atoms for Peace” program…”

Section: Introductionmentioning

confidence: 98%

Contemporary Chemistry of Berkelium and Californium

White

Dan

Albrecht‐Schönzart

2019

Chemistry A European J

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The merging of small‐scale syntheses and rapid crystallization methods have provided access to crystalline samples of berkelium (Z=97) and californium (Z=98) coordination complexes and compounds that can be interrogated with a suite of spectroscopic tools and structural elucidation approaches that have come online over the last 20 years. The combination of this experimental data with relativistic theoretical methods that capture the effects of spin‐orbit coupling and scalar relativistic effects have allowed us to understand the electronic structure of berkelium and californium compounds at a level of detail that was not previously possible. The harbinger of this new era of post‐curium chemistry was the synthesis and characterization of [Cf{B6O8(OH)5}]. This compound possesses a structure type that is distinct from earlier actinide borates, a reduction in coordination number for californium, contracted Cf−O bond lengths, a substantially reduced magnetic moment with respect to the calculated free‐ion moment and, most importantly, vibronically coupled broadband photoluminescence. Ligand‐field analysis also showed that the splitting of the ground state was larger than typically found in the f‐block elements, and when taken together places its overall electronic structure as a hybrid of d‐ and f‐block components. The discovery of the unusual properties of this compound has led to the development of large families of 4f and 5f coordination complexes, in an effort to uncover the underlying origin of the electronic structure oddities, and whether there really is a sharp onset of these changes at californium. This in turn pushed the development of far more challenging berkelium chemistry (from a radiologic standpoint) because the half‐life of the isotopes decreases from 351 years for 249Cf to 330 days for 249Bk. This short review details some of the chemistry that has been reported over the last 15 years, and its consequences for understanding the periodic table.

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