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Journal Articles

PANDORA Project for the study of photonuclear reactions below $$A=60$$

Tamii, Atsushi*; Pellegri, L.*; S$"o$derstr$"o$m, 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

Journal Articles

Improved measurement of the $$0_2^+rightarrow0_1^+$$ $$E$$0 transition strength for $$^{72}$$Se using the SPICE spectrometer

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

 Times Cited Count:2 Percentile:68.81(Physics, Nuclear)

Journal Articles

Compositional and structural analysis of Fukushima-derived particulates using high-resolution X-ray imaging and synchrotron characterisation techniques

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

 Times Cited Count:7 Percentile:35.66(Multidisciplinary Sciences)

Journal Articles

Provenance of uranium particulate contained within Fukushima Daiichi Nuclear Power Plant Unit 1 ejecta material

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

 Times Cited Count:24 Percentile:78.39(Multidisciplinary Sciences)

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$$_{2}$$, and identical in structure to reactor fuel. Confirmation that this U was of nuclear origin ($$^{235}$$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.

Journal Articles

Flow-electrode CDI removes the uncharged Ca-UO$$_{2}$$-CO$$_{3}$$ ternary complex from brackish potable groundwater; Complex dissociation, transport, and sorption

Ma, J.*; Zhang, Y.*; Collins, R. N.*; Tsarev, S.*; Aoyagi, Noboru; Kinsela, A. S.*; Jones, A. M.*; Waite, T. D.*

Environmental Science & Technology, 53(5), p.2739 - 2747, 2019/03

 Times Cited Count:41 Percentile:88.56(Engineering, Environmental)

Journal Articles

Neutron-hole states in $$^{131}$$Sn and spin-orbit splitting in neutron-rich nuclei

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

 Times Cited Count:7 Percentile:53.93(Astronomy & Astrophysics)

Journal Articles

Development of a radiological characterization submersible ROV for use at Fukushima Daiichi

Nancekievill, M.*; Jones, A. R.*; Joyce, M. J.*; Lennox, B.*; Watson, S.*; Katakura, Junichi*; Okumura, Keisuke; Kamada, So*; Kato, Michio*; Nishimura, Kazuya*

IEEE Transactions on Nuclear Science, 65(9), p.2565 - 2572, 2018/09

 Times Cited Count:19 Percentile:91.25(Engineering, Electrical & Electronic)

In order to contribute to the development of technology to search fuel debris submerged in water inside the primary containment vessel of the Fukushima Daiichi Nuclear Power Station, we are developing a remotely operated vehicle (ROV) system equipped with a compact radiation detector and sonar. A cerium bromide (CeBr$$_{3}$$) scintillator detector for dose rate monitoring and $$gamma$$ ray spectroscopy was integrated into ROV and experimentally validated with a $$^{137}$$Cs source, both in the conditions of laboratory and submerged. In addition, the ROV combined with the IMAGENEX 831L sonar could characterize the shape and size of a simulated fuel debris at the bottom of the water pool facility.

Journal Articles

A Remote-operated system to map radiation dose in the Fukushima Daiichi primary containment vessel

Nancekievill, M.*; Jones, A. R.*; Joyce, M. J.*; Lennox, B.*; Watson, S.*; Katakura, Junichi*; Okumura, Keisuke; Kamada, So*; Kato, Michio*; Nishimura, Kazuya*

Proceedings of 5th International Conference on Advancements in Nuclear Instrumentation Measurement Methods and their Applications (ANIMMA 2017) (USB Flash Drive), 6 Pages, 2017/06

We are developping a submersible ROV system, coupled with radiation detectors aimed at mapping the interior of the reactors at the Fukushima Daiichi Nuclear Power Station. To map the $$gamma$$-ray intensity environment a cerium bromide (CeBr$$_{3}$$) inorganic scintillator detector sensitive to $$gamma$$-rays has been incorporated into the ROV to measure $$gamma$$-ray intensity and identify radioactive isotopes. The ROV is a cylindrical shape with a diameter of about 150 mm, and it have two end caps of five pumps each allowing control of the ROV in 5 degree of freedom. It is possible to directly replace the CeBr$$_{3}$$ detector with a single crystal chemical vapour deposition (CVD) neutron detector with a $$^{6}$$Li convertor foil that is capable of mapping the thermal neutron flux.

Journal Articles

Instrumentation for diagnostics and control of laser-accelerated proton (ion) beams

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

 Times Cited Count:73 Percentile:88.97(Radiology, Nuclear Medicine & Medical Imaging)

Journal Articles

First prompt in-beam $$gamma$$-ray spectroscopy of a superheavy element; The $$^{256}$$Rf

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

 Times Cited Count:0 Percentile:0.04

The first prompt in-beam $$gamma$$-ray spectroscopy of a superheavy element, $$^{256}$$Rf, has been performed successfully. A development of an intense isotopically enriched $$^{50}$$Ti beam using the MIVOC method enabled us to perform this experiment. A rotational band up to a spin of 20 $$hbar$$ has been discovered in $$^{256}$$Rf, and its moment of inertia has been extracted. These data suggest that there is no evidence of a significant deformed shell gap at $$Z$$ = 104.

Journal Articles

Shell-structure and pairing interaction in superheavy nuclei; Rotational properties of the $$Z$$=104 nucleus $$^{256}$$Rf

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

 Times Cited Count:56 Percentile:88.57(Physics, Multidisciplinary)

Rotational band structure of the $$Z$$=104 nucleus $$^{256}$$Rf has been observed for the first time using an in-beam $$gamma$$-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 $$Z$$=104, which is predicted in a number of current self-consistent mean-field models.

Journal Articles

Bacterial production of organic acids enhances H$$_{2}$$O$$_{2}$$-dependent iodide oxidation

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

 Times Cited Count:49 Percentile:76.82(Engineering, Environmental)

In order to develop an understanding of the role that microorganisms play in the transport of $$^{129}$$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 (H$$_{2}$$O$$_{2}$$). 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 H$$_{2}$$O$$_{2}$$ to form strong iodide oxidizing agents, peroxy carboxylic acids, and (2) organic acid secretion led to enhanced rates of H$$_{2}$$O$$_{2}$$-dependent iodide oxidation by lowering the pH of the culture medium.

Journal Articles

Isomeric states observed in heavy neutron-rich nuclei populated in the fragmentation of a $$^{208}$$Pb beam

Steer, S. J.*; Podoly$'a$k, Z.*; Pietri, S.*; G$'o$rska, 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

 Times Cited Count:61 Percentile:94.44(Physics, Nuclear)

Heavy neutron-rich nuclei were populated via the fragmentation of a E/A=1 GeV $$_{82}^{208}$$Pb beam. Secondary fragments were separated and identified and subsequently implanted in a passive stopper. By the detection of delayed $$gamma$$ 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.

Journal Articles

Search for a 2-quasiparticle high-$$K$$ isomer in $$^{256}$$Rf

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

 Times Cited Count:32 Percentile:84.92(Physics, Nuclear)

We have identified an isomer with a half-life of 17 $$mu$$s in $$^{256}$$Rf through a calorimetric conversion electron measurement tagged with implanted $$^{256}$$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-$$K$$ 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 $$^{256}$$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.

Journal Articles

Bridging the nuclear structure gap between stable and super heavy nuclei

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

 Times Cited Count:7 Percentile:47.92(Physics, Nuclear)

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 $$^{252}$$No and $$^{254}$$No, and evaluated energies of proton single-particle orbitals around Z=100. We also found a new high-K three quasiparticle isomer in $$^{257}$$Rf. Energies of neutron single-particle orbitals were also evaluated from experimental data of the $$alpha$$ decay of $$^{257}$$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.

Journal Articles

Weakly deformed oblate structures in $$^{198}_{76}$$Os$$_{122}$$

Podoly$'a$k, Zs.*; Steer, S. J.*; Pietri, S.*; Xu, F. R.*; Liu, H. J.*; Regan, P. H.*; Rudolph, D.*; Garnsworthy, A. B.*; Hoischen, R.*; G$'o$rska, M.*; et al.

Physical Review C, 79(3), p.031305_1 - 031305_4, 2009/03

 Times Cited Count:32 Percentile:85.27(Physics, Nuclear)

$$gamma$$ rays de-exciting isomeric states in the neutron-rich nucleus $$_{76}^{198}$$Os$$_{122}$$ have been observed following relativistic projectile fragmentation of a 1 GeV per nucleon $$^{208}$$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.

Journal Articles

$$K^{pi}=8^{-}$$ isomers and $$K^{pi}=2^{-}$$ octupole vibrations in $$N=150$$ shell-stabilized isotones

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

 Times Cited Count:48 Percentile:90.59(Physics, Nuclear)

Isomers have been identified in $$^{246}$$Cm and $$^{252}$$No with quantum number $$K^{pi}=8^{-}$$, which decay through $$K^{pi}=2^{-}$$ rotational bands built on octupole vibrational states. For $$N=150$$ isotones with atomic number $$Z=94$$$$sim$$102, the $$K^{pi}=8^{-}$$ and 2$$^{-}$$ states have remarkably stable energies, indicating neutron excitations. An exception is a singular minimum in the 2$$^{-}$$ energy at $$^{246}$$Cm, due to the additional role of proton configurations.

Journal Articles

Neutron-proton pairing competition in $$N=Z$$ nuclei; Metastable state decays in the proton dripline nuclei $$^{82}_{41}$$Nb and $$^{86}_{43}$$Tc

Garnsworthy, A. B.*; Regan, P. H.*; C$'a$ceres, L.*; Pietri, S.*; Sun, Y.*; Rudolph, D.*; G$'o$rska, M.*; Podoly$'a$k, Z.*; Steer, S. J.*; Hoischen, R.*; et al.

Physics Letters B, 660(4), p.326 - 330, 2008/02

 Times Cited Count:25 Percentile:79.15(Astronomy & Astrophysics)

The low-lying structures of the self-conjugate ($$N=Z$$) nuclei $$^{82}_{41}$$Nb and $$^{86}_{43}$$Tc have been investigated using isomeric-decay spectroscopy following the projectile fragmentation of a $$^{107}$$Ag beam. These represent the heaviest odd-odd $$N=Z$$ nuclei in which internal decays have been identified to date. The resulting level schemes shed light on the shape evolution along the $$N=Z$$ line between the doubly-magic systems $$^{56}_{28}$$Ni and $$^{100}_{50}$$Sn and support a preference for $$T=1$$ states in $$T_z=0$$ odd-odd nuclei at low excitation energies associated with a $$T=1$$ neutron-proton pairing gap. Comparison with Projected Shell Model calculations suggests that the decay in $$^{82}$$Nb may be interpreted as an isospin-changing $$K$$ isomer.

Journal Articles

Isomeric decay studies around $$^{204}$$Pt and $$^{148}$$Tb

Podoly$'a$k, Zs.*; Steer, S. J.*; Pietri, S.*; Werner-Malento, E.*; Regan, P. H.*; Rudolph, D.*; Garnsworthy, A. B.*; Hoischen, R.*; G$'o$rska, M.*; Gerl, J.*; et al.

European Physical Journal; Special Topics, 150(1), p.165 - 168, 2007/11

 Times Cited Count:11 Percentile:55.77(Physics, Multidisciplinary)

Relativistic energy projectile fragmentation of $$^{208}$$Pb has been used to produce a range of exotic nuclei. The nuclei of interest were studied by detecting delayed $$gamma$$ rays following the decay of isomeric states. Experimental information on the excited states of the neutron-rich $$^{204}$$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 $$I=27hbar$$ and $$I=(49/2)hbar$$ states in $$^{148}$$Tb and $$^{147}$$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.

Journal Articles

Recent results in fragmentation isomer spectroscopy with rising

Pietri, S.*; Regan, P. H.*; Podoly$'a$k, Zs.*; Rudolph, D.*; Steer, S. J.*; Garnsworthy, A. B.*; Werner-Malento, E.*; Hoischen, R.*; G$'o$rska, M.*; Gerl, J.*; et al.

Nuclear Instruments and Methods in Physics Research B, 261(1-2), p.1079 - 1083, 2007/08

 Times Cited Count:92 Percentile:98.43(Instruments & Instrumentation)

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 $$gamma$$-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.

25 (Records 1-20 displayed on this page)