| 1. |
- Khuyagbaatar, J., et al.
(författare)
-
48Ca+249Bk Fusion Reaction Leading to Element Z=117: Long-Lived α-Decaying 270Db and Discovery of 266Lr
- 2014
-
Ingår i: Physical Review Letters. - 1079-7114. ; 112:17
-
Tidskriftsartikel (refereegranskat)abstract
- The superheavy element with atomic number Z=117 was produced as an evaporation residue in the 48Ca+249Bk fusion reaction at the gas-filled recoil separator TASCA at GSI Darmstadt, Germany. The radioactive decay of evaporation residues and their α-decay products was studied using a detection setup that allowed measuring decays of single atomic nuclei with half-lives between sub-μs and a few days. Two decay chains comprising seven α decays and a spontaneous fission each were identified and are assigned to the isotope 294-117 and its decay products. A hitherto unknown α-decay branch in 270Db (Z=105) was observed, which populated the new isotope 266Lr (Z=103). The identification of the long-lived (T1/2=1.0+1.9−0.4 h) α-emitter 270Db marks an important step towards the observation of even more long-lived nuclei of superheavy elements located on an “island of stability.”
|
|
| 2. |
|
|
| 3. |
- Forsberg, Ulrika, et al.
(författare)
-
Spectroscopic Tools Applied to Element Z = 115 Decay Chains
- 2014
-
Ingår i: EPJ Web of Conferences. - : EDP Sciences. - 2100-014X .- 2101-6275. - 9782759811755 - 9782759811762 ; 66, s. 02036-02036
-
Konferensbidrag (refereegranskat)abstract
- Nuclides that are considered to be isotopes of element Z = 115 were produced in the reaction 48Ca + 243Am at the GSI Helmholtzzentrum für Schwerionenforschung Darmstadt. The detector setup TASISpec was used. It was mounted behind the gas-filled separator TASCA. Thirty correlated α-decay chains were found, and the energies of the particles were determined with high precision. Two important spectroscopic aspects of the offline data analysis are discussed in detail: the handling of digitized preamplified signals from the silicon strip detectors, and the energy reconstruction of particles escaping to upstream detectors relying on pixel-by-pixel dead-layer thicknesses.
|
|
| 4. |
- Rudolph, Dirk, et al.
(författare)
-
Alpha-Photon Coincidence Spectroscopy Along Element 115 Decay Chains
- 2014
-
Ingår i: Acta Physica Polonica. Series B: Elementary Particle Physics, Nuclear Physics, Statistical Physics, Theory of Relativity, Field Theory. - 0587-4254. ; 45, s. 263-272
-
Tidskriftsartikel (refereegranskat)abstract
- Produced in the reaction 48Ca+243Am, thirty correlated α-decay chains were observed in an experiment conducted at the GSI Helmholzzentrum für Schwerionenforschung, Darmstadt, Germany. The decay chains are basically consistent with previous findings and are considered to originate from isotopes of element 115 with mass numbers 287, 288, and 289. A set-up aiming specifically for high-resolution charged particle and photon coincidence spectroscopy was placed behind the gas-filled separator TASCA. For the first time, γ rays as well as X-ray candidates were observed in prompt coincidence with the α-decay chains of element 115.
|
|
| 5. |
|
|
| 6. |
- Yakushev, A., et al.
(författare)
-
Superheavy Element Flerovium (Element 114) Is a Volatile Metal
- 2014
-
Ingår i: Inorganic Chemistry. - : American Chemical Society (ACS). - 1520-510X .- 0020-1669. ; 53:3, s. 1624-1629
-
Tidskriftsartikel (refereegranskat)abstract
- The electronic structure of superheavy elements (Z ≥ 104) and their chemical properties are dominated by relativistic effects. Recently two superheavy elements were recognized by the IUPAC and named flerovium (Fl, Z = 114) and livermorium (Lv, Z = 116). Fl is the heaviest element with which chemical experiments were performed. Here, we report on experiments that help answering the long-standing question whether Fl behaves rather like a noble gas or like a metal.
|
|
| 7. |
- Muller, C., et al.
(författare)
-
Promising Prospects for Sc-44-/Sc-47-Based Theragnostics: Application of Sc-47 for Radionuclide Tumor Therapy in Mice
- 2014
-
Ingår i: Journal of Nuclear Medicine. - : Society of Nuclear Medicine. - 0161-5505 .- 2159-662X. ; 55:10, s. 1658-1664
-
Tidskriftsartikel (refereegranskat)abstract
- In recent years, Sc-47 has attracted attention because of its favorable decay characteristics (half-life, 3.35 d; average energy, 162 key; Ey, 159 key) for therapeutic application and for SPECT imaging. The aim of the present study was to investigate the suitability of Sc-47 for radionuclide therapy in a preclinical setting. For this purpose a novel DOTA-folate conjugate (cm10) with an albumin-binding entity was used. Methods: Sc-47 was produced via the Ca-46(n,gamma)Ca-47 -> Sc beta-47 nuclear reaction at the high-flux reactor at the Institut Laue-Langevin. Separation of the Sc-47 from the target material was performed by a semi-automated process using extraction chromatography and cation exchange chromatography. Sc-47-labeled cm10 was tested on folate receptor-positive KB tumor cells in vitro. Biodistribution and SPECT imaging experiments were performed in KB tumor-bearing mice. Radionuclide therapy was conducted with two groups of mice, which received either Sc-47-cm10 (10 MBq) or only saline. Tumor growth and survival time were compared between the two groups of mice. Results: Irradiation of Ca-46 resulted in approximately 1.8 GBq of Ca-47, which subsequently decayed to Sc-47. Separation of Sc-47 from Ca-47 was obtained with 80% yield in only 10 min. The Sc-47 was then available in a small volume (-500 pL) of an ammonium acetate/HCI (pH 4.5) solution suitable for direct radiolabeling. Sc-47-cm10 was prepared with a radiochemical yield of more than 96% at a specific activity of up to 13 MBq/nmol. In vitro 475ccm10 showed folate receptor-specific binding and uptake into KB tumor cells. In vivo SPECT/CT images allowed the visualization of accumulated radioactivity in KB tumors and in the kidneys. The therapy study showed a significantly delayed tumor growth in mice, which received Sc-47-cm10 (10 MBq, 10 Gy) resulting in a more than 50% increase in survival time, compared with untreated control mice. Conclusion: With this study, we demonstrated the suitability of using Sc-47 for therapeutic purposes. On the basis of our recent results obtained with Sc-44-folate, the present work confirms the applicability of Sc-44/Sc-47 as an excellent matched pair of nuclides for PET imaging and radionuclide therapy.
|
|
