Tamii, Atsushi*; Pellegri, L.*; Sderstrm, P.-A.*; Allard, D.*; Goriely, S.*; Inakura, Tsunenori*; Khan, E.*; Kido, Eiji*; Kimura, Masaaki*; Litvinova, E.*; et al.
European Physical Journal A, 59(9), p.208_1 - 208_21, 2023/09
no abstracts in English
Smallcombe, J.; Garnsworthy, A. B.*; Korten, W.*; Singh, P.*; Ali, F. A.*; Andreoiu, C.*; Ansari, S.*; Ball, G. C.*; Barton, C. J.*; Bhattacharjee, S. S.*; et al.
Physical Review C, 106(1), p.014312_1 - 014312_9, 2022/07
Martin, P. G.*; Jones, C. P.*; Bartlett, S.*; Ignatyev, K.*; Megson-Smith, D.*; Satou, Yukihiko; Cipiccia, S.*; Batey, D. J.*; Rau, C.*; Sueki, Keisuke*; et al.
Scientific Reports (Internet), 10, p.22056_1 - 22056_17, 2020/12
Martin, P. G.*; Jones, C. P.*; Cipiccia, S.*; Batey, D. J.*; Hallam, K. R.*; Satou, Yukihiko; Griffiths, I.*; Rau, C.*; Richards, D. A.*; Sueki, Keisuke*; et al.
Scientific Reports (Internet), 10(1), p.1636_1 - 1636_11, 2020/01
Martin, P. G.*; Louvel, M.*; Cipiccia, S.*; Jones, C. P.*; Batey, D. J.*; Hallam, K. R.*; Yang, I. A. X.*; Satou, Yukihiko; Rau, C.*; Mosselmans, J. F. W.*; et al.
Nature Communications (Internet), 10, p.2801_1 - 2801_7, 2019/06
Synchrotron radiation (SR) analysis techniques alongside secondary ion mass spectrometry (SIMS) measurements have been made on sub-mm particulate material derived from reactor Unit 1 of the Fukushima Daiichi Nuclear Power Plant (FDNPP). Using these methods, it has been possible to investigate the distribution, state and isotopic composition of micron-scale U particulate contained within the larger Si-based ejecta material. Through combined SR micro-focused X-ray fluorescence (SR-micro-XRF) and absorption contrast SR micro-focused X-ray tomography (SR-micro-XRT), the U particulate was found to be located around the exterior circumference of the highly-porous particle. Synchrotron radiation micro-focused X-ray absorption near edge structure (SR-micro-XANES) analysis of a number of these entrapped particles revealed them to exist within the U(IV) oxidation state, as UO, and identical in structure to reactor fuel. Confirmation that this U was of nuclear origin (U-enriched) was provided through secondary ion mass spectrometry (SIMS) analysis with an isotopic enrichment ratio characteristic of a provenance from reactor Unit 1 at the FDNPP. These results provide clear evidence of the event scenario (that a degree of core fragmentation and release occurred from reactor Unit 1), with such spent fuel ejecta existing; (i) within the stable U(IV) oxidation state; and (ii) contained within a bulk Si-based particle. While this U is unlikely to represent an environmental or health hazard, such assertions would likely change, however, should break-up of the Si-containing bulk particle occur. However, more important to the long-term decommissioning of the reactors (and clean-up) on the FDNPP, is the knowledge that core integrity of reactor Unit 1 was compromised with nuclear material existing outside of the reactors primary containment.
Orlandi, R.; Pain, S. D.*; Ahn, S.*; Jungclaus, A.*; Schmitt, K. T.*; Bardayan, D. W.*; Catford, W. N.*; Chapman, R.*; Chipps, K. A.*; Cizewski, J. A.*; et al.
Physics Letters B, 785, p.615 - 620, 2018/10
Bolton, P.; Borghesi, M.*; Brenner, C.*; Carroll, D. C.*; De Martinis, C.*; Fiorini, F.*; Flacco, A.*; Floquet, V.*; Fuchs, J.*; Gallegos, P.*; et al.
Physica Medica; European Journal of Medical Physics, 30(3), p.255 - 270, 2014/05
Rubert, J.*; Dorvaux, O.*; Gall, B. J. P.*; Greenlees, P. T.*; Asfari, Z.*; Piot, J.*; Andersson, L. L.*; Asai, Masato; Cox, D. M.*; Dechery, F.*; et al.
Journal of Physics; Conference Series, 420, p.012010_1 - 012010_10, 2013/03
The first prompt in-beam -ray spectroscopy of a superheavy element, Rf, has been performed successfully. A development of an intense isotopically enriched Ti beam using the MIVOC method enabled us to perform this experiment. A rotational band up to a spin of 20 has been discovered in Rf, and its moment of inertia has been extracted. These data suggest that there is no evidence of a significant deformed shell gap at = 104.
Greenlees, P. T.*; Rubert, J.*; Piot, J.*; Gall, B. J. P.*; Andersson, L. L.*; Asai, Masato; Asfari, Z.*; Cox, D. M.*; Dechery, F.*; Dorvaux, O.*; et al.
Physical Review Letters, 109(1), p.012501_1 - 012501_5, 2012/07
Rotational band structure of the =104 nucleus Rf has been observed for the first time using an in-beam -ray spectroscopic technique. This nucleus is the heaviest among the nuclei whose rotational band structure has ever been observed. Thus, the present result provides valuable information on the single-particle shell structure and pairing interaction in the heaviest extreme of nuclei. The deduced moment of inertia indicates that there is no deformed shell gap at =104, which is predicted in a number of current self-consistent mean-field models.
Li, H.-P.*; Yeager, C. M.*; Brinkmeyer, R.*; Zhang, S.*; Ho, Y.-F.*; Xu, C.*; Jones, W. L.*; Schwehr, K. A.*; Otosaka, Shigeyoshi; Roberts, K. A.*; et al.
Environmental Science & Technology, 46(9), p.4837 - 4844, 2012/03
In order to develop an understanding of the role that microorganisms play in the transport of I in soil-water systems, naturally occurring bacteria isolated from the F-area subsurface of the Savannah River Site (SRS) were assessed for iodide oxidizing activity. Spent liquid medium from a number of SRS bacterial cultures enhanced iodide oxidation 2-10 fold in the presence of hydrogen peroxide (HO). From a time-series measurements of peroxidase activities and organic acid concentrations, it was hypothesized that microbial organic acid exudate promoted iodide oxidation via following mechanisms; (1) organic acids interact with HO to form strong iodide oxidizing agents, peroxy carboxylic acids, and (2) organic acid secretion led to enhanced rates of HO-dependent iodide oxidation by lowering the pH of the culture medium.
Steer, S. J.*; Podolyk, Z.*; Pietri, S.*; Grska, M.*; Grawe, H.*; Maier, K.*; Regan, P. H.*; Rudolph, D.*; Garnsworthy, A. B.*; Hoischen, R.*; et al.
Physical Review C, 84(4), p.044313_1 - 044313_22, 2011/10
Heavy neutron-rich nuclei were populated via the fragmentation of a E/A=1 GeV Pb beam. Secondary fragments were separated and identified and subsequently implanted in a passive stopper. By the detection of delayed rays, isomeric decays associated with these nuclei have been identified. A total of 49 isomers were detected, with the majority of them observed for the first time. Possible level schemes are constructed and the structure of the nuclei discussed. To aid the interpretation, shell-model as well as BCS calculations were performed.
Robinson, A. P.*; Khoo, T. L.*; Seweryniak, D.*; Ahmad, I.*; Asai, Masato; Back, B. B.*; Carpenter, M. P.*; Chowdhury, P.*; Davids, C. N.*; Greene, J.*; et al.
Physical Review C, 83(6), p.064311_1 - 064311_7, 2011/06
We have identified an isomer with a half-life of 17 s in Rf through a calorimetric conversion electron measurement tagged with implanted Rf nuclei using the fragment mass analyzer at Argonne National Laboratory. The low population yield for this isomer suggests that this isomer should not be a 2-quasiparticle high- isomer which is typically observed in the N = 152 isotones, but should be a 4-quasiparticle one. Possible reasons of the non-observation of a 2-quasiparticle isomer are this isomer decays by fission with a half-life similar to that of the ground state of Rf. Another possibility, that there is no 2-quasiparticle isomer at all, would imply an abrupt termination of axially symmetric deformed shape at Z=104.
Yui, Mikazu; Ishikawa, Hirohisa; Watanabe, Atsuo*; Yoshino, Kyoji*; Umeki, Hiroyuki; Hioki, Kazumasa; Naito, Morimasa; Seo, Toshihiro; Makino, Hitoshi; Oda, Chie; et al.
JAEA-Research 2010-015, 106 Pages, 2010/05
This report summarizes the activity of Phase I of Waste Management Working Group of the United States - Japan Joint Nuclear Energy Action Plan started in 2007. The working group focused on consolidation of the existing technical basis between the U.S. and Japan and the joint development of a plan for future collaborative activities. Firstly, the political/regulatory frameworks related to nuclear fuel cycles in both countries were reviewed. The various advanced fuel cycle scenarios in both countries were surveyed and summarized. Secondly, the waste management/disposal system optimization was discussed. Repository system concepts for the various classifications of nuclear waste were reviewed and summarized, then disposal system optimization processes and techniques were reviewed, and factors to consider in future repository design optimization activities were also discussed. Finally the potential collaboration areas and activities related to the optimization problem were extracted.
Seweryniak, D.*; Khoo, T. L.*; Ahmad, I.*; Kondev, F. G.*; Robinson, A.*; Tandel, S. K.*; Asai, Masato; Back, B. B.*; Carpenter, M. P.*; Chowdhury, P.*; et al.
Nuclear Physics A, 834(1-4), p.357c - 361c, 2010/03
Experimental data on single-particle energies in nuclei around Z=100 and N=152 play an important role to test validity of theoretical predictions for shell structure of superheavy nuclei. We found high-K two-quasiparticle isomers in No and No, and evaluated energies of proton single-particle orbitals around Z=100. We also found a new high-K three quasiparticle isomer in Rf. Energies of neutron single-particle orbitals were also evaluated from experimental data of the decay of Rf. Comparisons between the present experimental data and various theoretical calculations for the proton single-particle orbitals indicate that the calculation by using the Woods-Saxon potential gives the best agreement with the data.
Podolyk, Zs.*; Steer, S. J.*; Pietri, S.*; Xu, F. R.*; Liu, H. J.*; Regan, P. H.*; Rudolph, D.*; Garnsworthy, A. B.*; Hoischen, R.*; Grska, M.*; et al.
Physical Review C, 79(3), p.031305_1 - 031305_4, 2009/03
rays de-exciting isomeric states in the neutron-rich nucleus Os have been observed following relativistic projectile fragmentation of a 1 GeV per nucleon Pb beam. The ground-state band has properties compatible with oblate deformation. The evolution of the structure of Os isotopes characterized by sudden prolate-oblate shape change is discussed and contrasted with the smooth change known in the Pt chain.
Robinson, A. P.*; Khoo, T. L.*; Ahmad, I.*; Tandel, S. K.*; Kondev, F. G.*; Nakatsukasa, Takashi*; Seweryniak, D.*; Asai, Masato; Back, B. B.*; Carpenter, M. P.*; et al.
Physical Review C, 78(3), p.034308_1 - 034308_6, 2008/09
Isomers have been identified in Cm and No with quantum number , which decay through rotational bands built on octupole vibrational states. For isotones with atomic number 102, the and 2 states have remarkably stable energies, indicating neutron excitations. An exception is a singular minimum in the 2 energy at Cm, due to the additional role of proton configurations.
Garnsworthy, A. B.*; Regan, P. H.*; Cceres, L.*; Pietri, S.*; Sun, Y.*; Rudolph, D.*; Grska, M.*; Podolyk, Z.*; Steer, S. J.*; Hoischen, R.*; et al.
Physics Letters B, 660(4), p.326 - 330, 2008/02
The low-lying structures of the self-conjugate () nuclei Nb and Tc have been investigated using isomeric-decay spectroscopy following the projectile fragmentation of a Ag beam. These represent the heaviest odd-odd nuclei in which internal decays have been identified to date. The resulting level schemes shed light on the shape evolution along the line between the doubly-magic systems Ni and Sn and support a preference for states in odd-odd nuclei at low excitation energies associated with a neutron-proton pairing gap. Comparison with Projected Shell Model calculations suggests that the decay in Nb may be interpreted as an isospin-changing isomer.
Podolyk, Zs.*; Steer, S. J.*; Pietri, S.*; Werner-Malento, E.*; Regan, P. H.*; Rudolph, D.*; Garnsworthy, A. B.*; Hoischen, R.*; Grska, M.*; Gerl, J.*; et al.
European Physical Journal; Special Topics, 150(1), p.165 - 168, 2007/11
Relativistic energy projectile fragmentation of Pb has been used to produce a range of exotic nuclei. The nuclei of interest were studied by detecting delayed rays following the decay of isomeric states. Experimental information on the excited states of the neutron-rich Pt N=126 nucleus, following internal decay of two isomeric states, was obtained for the first time. In addition, decays from the previously reported isomeric and states in Tb and Gd, respectively, have been observed. These isomeric decays represent the highest discrete states observed to date following a prejectile fragmentation reaction, and opens up the possibilty of doing "high-spin physics" using this technique.
Pietri, S.*; Regan, P. H.*; Podolyk, Zs.*; Rudolph, D.*; Steer, S. J.*; Garnsworthy, A. B.*; Werner-Malento, E.*; Hoischen, R.*; Grska, M.*; Gerl, J.*; et al.
Nuclear Instruments and Methods in Physics Research B, 261(1-2), p.1079 - 1083, 2007/08
The first results from the stopped beam RISING experimental campaign performed at the GSI laboratory in Darmstadt, Germany, are presented. RISING constitutes a major new experimental program in European nuclear structure physics research aimed at using relativistic energy (typically around 1 GeV per nucleon) projectile fragmentation reactions to populate nuclei with highly exotic proton-to-neutron ratios compared to the line of beta stability. In its high-efficiency stopped beam configuration, the RISING -ray spectrometer consists of 105 individual germanium crystals which view a focal plane in which the exotic nuclei are brought to rest. Here, decays from metastable states with half-lives in the nano to milliseconds range can be observed. Results of initial commissioning experiments are also shown and details of the planned future experimental program are given.
Ioki, Kimihiro*; Barabaschi, P.*; Barabash, V.*; Chiocchio, S.*; Daenner, W.*; Elio, F.*; Enoeda, Mikio; Gervash, A.*; Ibbott, C.*; Jones, L.*; et al.
Nuclear Fusion, 43(4), p.268 - 273, 2003/04
Although the basic concept of the vacuum vessel (VV) and in-vessel components of the ITER design has stayed the same, there have been several detailed design improvements resulting from efforts to raise reliability, to improve maintainability and to save money. One of the most important achievements in the VV R&D has been demonstration of the necessary fabrication and assembly tolerances. Recently the deformation due to cutting of the port extension was measured and it was shown that the deformation is small and acceptable. Further development of advanced methods of cutting, welding and NDT on a thick plate have been continued in order to refine manufacturing and improve cost and technical performance. With regard to the related FW/blanket and divertor designs, the R&D has resulted in the development of suitable technologies. Prototypes of the FW panel, the blanket shield block and the divertor components have been successfully fabricated.