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1. Radiative Decay of the $^{229m}$Th Nuclear Clock Isomer in Different Host Materials

Author

Pineda, S. V., Chhetri, P., Bara, S., Elskens, Y., Casci, S., Alexandrova, A. N., Au, M., Athanasakis-Kaklamanakis, M., Bartokos, M., Beeks, K., Bernerd, C., Claessens, A., Chrysalidis, K., Cocolios, T. E., Correia, J. G., De Witte, H., Elwell, R., Ferrer, R., Heinke, R., Hudson, E. R., Ivandikov, F., Kudryavtsev, Yu., Köster, U., Kraemer, S., Laatiaoui, M., Lica, R., Merckling, C., Morawetz, I., Morgan, H. W. T., Moritz, D., Pereira, L. M. C., Raeder, S., Rothe, S., Schaden, F., Scharl, K., Schumm, T., Stegemann, S., Terhune, J., Thirolf, P. G., Tunhuma, S. M., Bergh, P. Van Den, Van Duppen, P., Vantomme, A., Wahl, U., and Yue, Z.

Subjects
Nuclear Experiment
Abstract

A comparative vacuum ultraviolet spectroscopy study conducted at ISOLDE-CERN of the radiative decay of the $^{229m}$Th nuclear clock isomer embedded in different host materials is reported. The ratio of the number of radiative decay photons and the number of $^{229m}$Th embedded are determined for single crystalline CaF$_2$, MgF$_2$, LiSrAlF$_6$, AlN, and amorphous SiO$_2$. For the latter two materials, no radiative decay signal was observed and an upper limit of the ratio is reported. The radiative decay wavelength was determined in LiSrAlF$_6$ and CaF$_2$, reducing its uncertainty by a factor of 2.5 relative to our previous measurement. This value is in agreement with the recently reported improved values from laser excitation.

Published
2024
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2. Production and purification of molecular 225Ac at CERN-ISOLDE

Author

Au, M., Nies, L., Stegemann, S., Athanasakis-Kaklamanakis, M., Cocolios, T. E., Fischer, P., Giesel, P. F., Johnson, J. D., Köster, U., Lange, D., Mougeot, M., Reilly, J., Schlaich, M., Schweiger, Ch., Schweikhard, L., Wienholtz, F., Wojtaczka, W., Düllmann, Ch. E., and Rothe, S.

Published
2025
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3. Production study of Fr, Ra and Ac radioactive ion beams at ISOLDE, CERN

Author

Jajčišinová, E., Dockx, K., Au, M., Bara, S., Cocolios, T. E., Chrysalidis, K., Farooq-Smith, G. J., Fedorov, D. V., Fedosseev, V. N., Flanagan, K. T., Heines, M., Houngbo, D., Johnson, J. D., Kellerbauer, A., Kraemer, S., Marsh, B. A., Popescu, L., Ramos, J. P., Rothe, S., Seliverstov, M. D., Sels, S., Stegemann, S., Stryjczyk, M., and Verelst, V.

Published
2024
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4. Production of neptunium and plutonium nuclides from uranium carbide using 1.4-GeV protons

Author

Au, M., Athanasakis-Kaklamanakis, M., Nies, L., Heinke, R., Chrysalidis, K., Köster, U., Kunz, P., Marsh, B., Mougeot, M., Schweikhard, L., Stegemann, S., Gracia, Y. Vila, Düllmann, Ch. E., and Rothe, S.

Subjects
Nuclear Experiment
Abstract

Accelerator-based techniques are one of the leading ways to produce radioactive nuclei. In this work, the Isotope Separation On-Line method was employed at the CERN-ISOLDE facility to produce neptunium and plutonium from a uranium carbide target material using 1.4-GeV protons. Neptunium and plutonium were laser-ionized and extracted as 30-keV ion beams. A Multi-Reflection Time-of-Flight mass spectrometer was used for ion identification by means of time-of-flight measurements as well as for isobaric separation. Isotope shifts were investigated for the 395.6-nm ground state transition in $^{236,237,239}$Np and the 413.4-nm ground state transition in $^{236,239,240}$Pu. Rates of $^{235-241}$Np and $^{234-241}$Pu ions were measured and compared with predictions of in-target production mechanisms simulated with GEANT4 and FLUKA to elucidate the processes by which these nuclei, which contain more protons than the target nucleus, are formed. $^{241}$Pu is the heaviest nuclide produced and identified at a proton-accelerator-driven facility to date. We report the availability of neptunium and plutonium as two additional elements at CERN-ISOLDE and discuss the limit of accelerator-based isotope production at high-energy proton accelerator facilities for nuclides in the actinide region., Comment: 12 pages, 12 figures

Published
2023
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5. In-source and in-trap formation of molecular ions in the actinide mass range at CERN-ISOLDE

Author

Au, M., Athanasakis-Kaklamanakis, M., Nies, L., Ballof, J., Berger, R., Chrysalidis, K., Fischer, P., Heinke, R., Johnson, J., Köster, U., Leimbach, D., Marsh, B., Mougeot, M., Reilly, J., Reis, E., Schlaich, M., Schweiger, Ch., Schweikhard, L., Stegemann, S., Wessolek, J., Wienholtz, F., Wilkins, S. G., Wojtaczka, W., Düllmann, Ch. E., and Rothe, S.

Subjects
Physics - Instrumentation and Detectors
Abstract

The use of radioactive molecules for fundamental physics research is a developing interdisciplinary field limited dominantly by their scarce availability. In this work, radioactive molecular ion beams containing actinide nuclei extracted from uranium carbide targets are produced via the Isotope Separation On-Line technique at the CERN-ISOLDE facility. Two methods of molecular beam production are studied: extraction of molecular ion beams from the ion source, and formation of molecular ions from the mass-separated ion beam in a gas-filled radio-frequency quadrupole ion trap. Ion currents of U$^+$, UO$_{1-3}^+$, UC$_{1-3}^+$, UF$_{1-4}^+$, UF$_{1,2}$O$_{1,2}^+$ are reported. Metastable tantalum and uranium fluoride molecular ions are identified. Formation of UO$_{1-3}^+$, U(OH)$_{1-3}^+$, UC$_{1-3}^+$, UF$_{1,2}$O$_{1,2}^+$ from mass-separated beams of U$^+$, UF$_{1,2}^+$ with residual gas is observed in the ion trap. The effect of trapping time on molecular formation is presented., Comment: 6 pages, 7 figures

Published
2023
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7. Targets and ion sources at CERN-ISOLDE — Facilities and developments

Author

Rothe, S., Au, M., Ballof, J., Barbero, E., Bissell, M., Boucherie, A., Bovigny, M., Chrysalidis, K., Crepieux, B., Cruikshank, J., Fadakis, E., Heinke, R., Josa, F., Le, L., Koliatos, A., Piselli, E., Reis, E., Samothrakis, V., Schütt, M., Lambert, L., Leimbach, D., Marzari, S., Owen, M., Stegemann, S., and Vila Gracia, Y.N.

Published
2023
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10. The CERN-ISOLDE fast tape station

Author

Stegemann, S., Atanasov, D., Au, M., Grenier-Boley, E., Butcher, M., Duraffourg, M., Fadakis, E., Feniet, T., Gracia, Y.N. Vila, Giles, T., Konki, J., Le, L., Lică, R., Martins, P., Matheson, E., Mihai, C., Muniz, R. Martinez, Neacşu, C., Pascovici, G., Szczurek, K.A., Warren, S., and Rothe, S.

Published
2023
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12. Production and purification of molecular 225Ac at CERN-ISOLDE.

Author

Au, M., Nies, L., Stegemann, S., Athanasakis-Kaklamanakis, M., Cocolios, T. E., Fischer, P., Giesel, P. F., Johnson, J. D., Köster, U., Lange, D., Mougeot, M., Reilly, J., Schlaich, M., Schweiger, Ch., Schweikhard, L., Wienholtz, F., Wojtaczka, W., Düllmann, Ch. E., and Rothe, S.

Subjects
RADIOISOTOPES, TIME-of-flight mass spectrometry, IONS, ISOTOPE separation, MOLECULAR beams
Abstract

The radioactive nuclide 225Ac is one of the few promising candidates for cancer treatment by targeted- α -therapy, but worldwide production of 225Ac faces significant limitations. In this work, the Isotope Separation On-Line method was used to produce actinium by irradiating targets made of uranium carbide and thorium carbide with 1.4-GeV protons. Actinium fluoride molecules were formed, ionized through electron impact, then extracted and mass-separated as a beam of molecular ions. The composition of the mass-selected ion beam was verified using time-of-flight mass spectrometry, α - and γ -ray decay spectrometry. Extracted quantities of 225 Ac 19 F 2 + particles per μ C of incident protons were 3.9 (3) × 10 7 from a uranium carbide target and 4.3 (4) × 10 7 for a thorium carbide target. Using a magnetic mass separator, the long-lived contamination 227 Ac is suppressed to < 5.47 × 10 - 7 (95% confidence interval) with respect to 225Ac by activity. Measured rates scale to collections of 108 kBq μ A - 1 h - 1 of directly produced 225 Ac 19 F 2 + . [ABSTRACT FROM AUTHOR]

Published
2025
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14. Evolution of E2 transition strength in deformed hafnium isotopes from new measurements on $^{172}$Hf, $^{174}$Hf, and $^{176}$Hf

Author

Rudigier, M., Nomura, K., Dannhoff, M., Gerst, R-B., Jolie, J., Saed-Samii, N., Stegemann, S., Régis, J-M., Robledo, L. M., Rodríguez-Guzmán, R., Blazhev, A., Fransen, Ch., Warr, N., and Zell, K. O.

Subjects
Nuclear Experiment, Nuclear Theory
Abstract

The available data for E2 transition strengths in the region between neutron-deficient Hf and Pt isotopes are far from complete. More and precise data are needed to enhance the picture of structure evolution in this region and to test state-of-the-art nuclear models. In a simple model, the maximum collectivity is expected at the middle of the major shell. However, for actual nuclei, this picture may no longer be the case, and one should use a more realistic nuclear-structure model. We address this point by studying the spectroscopy of Hf. We remeasure the 2^+_1 half-lives of 172,174,176Hf, for which there is some disagreement in the literature. The main goal is to measure, for the first time, the half-lives of higher-lying states of the rotational band. The new results are compared to a theoretical calculation for absolute transition strengths. The half-lives were measured using \gamma-\gamma and conversion-electron-\gamma delayed coincidences with the fast timing method. For the determination of half-lives in the picosecond region, the generalized centroid difference method was applied. For the theoretical calculation of the spectroscopic properties, the interacting boson model is employed, whose Hamiltonian is determined based on microscopic energy-density functional calculations. The measured 2^+_1 half-lives disagree with results from earlier \gamma-\gamma fast timing measurements, but are in agreement with data from Coulomb excitation experiments and other methods. Half-lives of the 4^+_1 and 6^+_1 states were measured, as well as a lower limit for the 8^+_1 states. We show the importance of the mass-dependence of effective boson charge in the description of E2 transition rates in chains of nuclei. It encourages further studies of the microscopic origin of this mass dependence. New data on transition rates in nuclei from neighboring isotopic chains could support these studies., Comment: 16 pages, 16 figures, 7 tables; Abstract shortened due to character limit

Published
2015
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17. Magnetic moments of thallium isotopes in the vicinity of magic N = 126

Author

Yue, Z., primary, Andreyev, A.N., additional, Barzakh, A.E., additional, Borzov, I.N., additional, Cubiss, J.G., additional, Algora, A., additional, Au, M., additional, Balogh, M., additional, Bara, S., additional, Bark, R.A., additional, Bernerd, C., additional, Borge, M.J.G., additional, Brugnara, D., additional, Chrysalidis, K., additional, Cocolios, T.E., additional, De Witte, H., additional, Favier, Z., additional, Fraile, L.M., additional, Fynbo, H.O.U., additional, Gottardo, A., additional, Grzywacz, R., additional, Heinke, R., additional, Illana, A., additional, Jones, P.M., additional, Judson, D.S., additional, Korgul, A., additional, Köster, U., additional, Labiche, M., additional, Le, L., additional, Lica, R., additional, Madurga, M., additional, Marginean, N., additional, Marsh, B., additional, Mihai, C., additional, Nácher, E., additional, Neacsu, C., additional, Nita, C., additional, Olaizola, B., additional, Orce, J.N., additional, Page, C.A.A., additional, Page, R.D., additional, Pakarinen, J., additional, Papadakis, P., additional, Penyazkov, G., additional, Perea, A., additional, Piersa-Siłkowska, M., additional, Podolyák, Zs., additional, Prosnyak, S.D., additional, Reis, E., additional, Rothe, S., additional, Sedlak, M., additional, Skripnikov, L.V., additional, Sotty, C., additional, Stegemann, S., additional, Tengblad, O., additional, Tolokonnikov, S.V., additional, Udías, J.M., additional, Van Duppen, P., additional, Warr, N., additional, and Wojtaczka, W., additional

Published
2024
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18. Fast-timing Investigation of \(A=128\) Isobars Populated in the \(\beta \)-decay of \(^{128}\)Cd

Author

Llanos-Expósito, M., primary, Fraile, L.M., additional, Benito, J., additional, Acosta, J., additional, Algora, A., additional, Andel, B., additional, Andreyev, A.N., additional, Antalic, S., additional, Bark, R.A., additional, Bernerd, C., additional, Bernier, N., additional, Bhengu, B., additional, Bittner, D., additional, Borge, M.J.G., additional, Briz, J.A., additional, Chrysalidis, K., additional, Cocolios, T.E., additional, Costache, C., additional, Cubiss, J.G., additional, De Witte, H., additional, Encina, N., additional, Esmaylzadeh, A., additional, Favier, Z., additional, Fernández, D., additional, Ferrera, C., additional, Fynbo, H.O.U., additional, García-Távora, V., additional, Georgiev, G., additional, Górska, M., additional, Heinke, R., additional, Herraiz, J.L., additional, Illana, A., additional, Jones, P., additional, Judson, D.S., additional, Jungclaus, A., additional, Karny, M., additional, Korgul, A., additional, Köster, U., additional, Kröll, Th., additional, Labiche, M., additional, Lalkovski, S., additional, Lesch, B., additional, Ley, M., additional, Lică, R., additional, Madurga, M., additional, Mărginean, N., additional, Marsh, B.A., additional, Miernik, K., additional, Mihai, C., additional, Mikolajczuk, M., additional, Mišt, J., additional, Murias, J.R., additional, Nácher, E., additional, Neacsu, C., additional, Nouvilas, V.M., additional, Ntshangase, S., additional, Olaizola, B., additional, Orce, J.N., additional, Page, C., additional, Pakarinen, J., additional, Papadakis, P., additional, Perea, A., additional, Piersa-Siłkowska, M., additional, Podolyak, Zs., additional, Rog, J., additional, Rothe, S., additional, Rozwoda, B., additional, Sánchez-Tembleque, V., additional, Solak, K., additional, Stegemann, S., additional, Stepaniuk, M., additional, Stoica, A., additional, Stryjczyk, M., additional, Tengblad, O., additional, Turturica, A., additional, Turturica, G., additional, Udías, J.M., additional, Ujeniuc, S., additional, Van Duppen, P., additional, von Tresckow, M., additional, Vasilev, I., additional, Warr, N., additional, Yue, Z., additional, and Zajda, S., additional

Published
2024
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20. In-source and in-trap formation of molecular ions in the actinide mass range at CERN-ISOLDE

Author

Au, M., primary, Athanasakis-Kaklamanakis, M., additional, Nies, L., additional, Ballof, J., additional, Berger, R., additional, Chrysalidis, K., additional, Fischer, P., additional, Heinke, R., additional, Johnson, J., additional, Köster, U., additional, Leimbach, D., additional, Marsh, B., additional, Mougeot, M., additional, Reich, B., additional, Reilly, J., additional, Reis, E., additional, Schlaich, M., additional, Schweiger, Ch., additional, Schweikhard, L., additional, Stegemann, S., additional, Wessolek, J., additional, Wienholtz, F., additional, Wilkins, S.G., additional, Wojtaczka, W., additional, Düllmann, Ch.E., additional, and Rothe, S., additional

Published
2023
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21. Production of neptunium and plutonium nuclides from uranium carbide using 1.4-GeV protons

Author

Au, M., primary, Athanasakis-Kaklamanakis, M., additional, Nies, L., additional, Heinke, R., additional, Chrysalidis, K., additional, Köster, U., additional, Kunz, P., additional, Marsh, B., additional, Mougeot, M., additional, Schweikhard, L., additional, Stegemann, S., additional, Vila Gracia, Y., additional, Düllmann, Ch. E., additional, and Rothe, S., additional

Published
2023
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23. Fast-Timing Lifetime Measurement of Hf

Author

Wiederhold, J., Werner, V., Kern, R., Pietralla, N., Bucurescu, D., Carroll, R., Cooper, N., Daniel, T., Filipescu, D., Florea, N., Gerst, R.-B., Ghita, D., Gurgi, L., Jolie, J., Ilieva, R., Lica, R., Marginean, N., Marginean, R., Mihai, C., Mitu, I. O., Naqvi, F., Nita, C., Rudigier, M., Stegemann, S., Pascu, S., Regan, P. H., García-Ramos, José-Enrique, editor, Andrés, María V., editor, Valera, José A. Lay, editor, Moro, Antonio M., editor, and Pérez-Bernal, Francisco, editor

Published
2019
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24. Fast-Timing Lifetime Measurement of $$^{174,176,178,180}$$ 174 , 176 , 178 , 180 Hf

Author

Wiederhold, J., primary, Werner, V., additional, Kern, R., additional, Pietralla, N., additional, Bucurescu, D., additional, Carroll, R., additional, Cooper, N., additional, Daniel, T., additional, Filipescu, D., additional, Florea, N., additional, Gerst, R.-B., additional, Ghita, D., additional, Gurgi, L., additional, Jolie, J., additional, Ilieva, R., additional, Lica, R., additional, Marginean, N., additional, Marginean, R., additional, Mihai, C., additional, Mitu, I. O., additional, Naqvi, F., additional, Nita, C., additional, Rudigier, M., additional, Stegemann, S., additional, Pascu, S., additional, and Regan, P. H., additional

Published
2019
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28. Commentary on the EMA reflection paper on the pharmaceutical development of medicines for use in the older population

Author

Riet-Nales, D.A. van, Bemt, B.J.F van den, Bodegom, D. van, Cerreta, F., Dooley, Brian, Eggenschwyler, D., Hirschlérova, B., Jansen, P.A.F., Karapinar-Çarkit, F., Moran, A., Span, J., Stegemann, S., Sundberg, K., Riet-Nales, D.A. van, Bemt, B.J.F van den, Bodegom, D. van, Cerreta, F., Dooley, Brian, Eggenschwyler, D., Hirschlérova, B., Jansen, P.A.F., Karapinar-Çarkit, F., Moran, A., Span, J., Stegemann, S., and Sundberg, K.

Abstract

Item does not contain fulltext, Older people are often affected by impaired organ and bodily functions resulting in multimorbidity and polypharmacy, turning them into the main user group of many medicines. Very often, medicines have not specifically been developed for older people, causing practical medication problems for them like limited availability of easy to swallow formulations, easy to open packaging and dosing instructions for enteral administration. In 2020, the European Medicines Agency (EMA) published a reflection paper 'Pharmaceutical development of medicines for use in the older population', which discusses how the emerging needs of an ageing European population can be addressed by medicines regulation. The paper intends to help industry to better consider the needs of older people during pharmaceutical/clinical medicines development by summarising data on the most relevant topics, providing early suggestions on how to move forward and prompting expert discussions and studies into knowledge gaps. Topics include patient acceptability, (dis)advantages of an administration route, formulation, dosage form, packaging, dosing device and user instruction. While the paper is directed at older people and the pharmaceutical industry, the reflections are also relevant to younger patients with similar disease-related needs and of value to other stakeholders parties, e.g., healthcare professionals, academics, patients and caregivers, as the paper makes clear what can be expected from industry and where collaborative work is needed. This commentary provides an overview of the different steps in the development of the reflection paper, discusses points considered most controversial and/or subject to (multidisciplinary) expert discussions and indicates their value for real world clinical practice.

Published
2022

32. Competition between Allowed and First-Forbidden $beta$ Decay: The Case of $^208Hgrightarrow^208Tl$

Author

Carroll, R. J., Podolyák, Zs., Berry, T., Grawe, H., Alexander, T., Andreyev, A. N., Ansari, S., Borge, M. J. G., Brunet, M., Creswell, J. R., Fraile, L. M., Fahlander, C., Fynbo, H. O. U., Gamba, E. R., Gelletly, W., Gerst, R.-B., Górska, M., Gredley, A., Greenlees, P. T., Harkness-Brennan, L. J., Huyse, M., Judge, S. M., Judson, D. S., Konki, J., Kurcewicz, J., Kuti, I., Lalkovski, S., Lazarus, I. H., Licifmmode ăelse ă, R., Lund, M., Madurga, M., Marginean, N., Marginean, R., Marroquin, I., Mihai, C., Mihai, R. E., Nácher, E., Negret, A., Nita, C., Pascu, S., Page, R. D., Patel, Z., Perea, A., Phrompao, J., Piersa, M., Pucknell, V., Rahkila, P., Rapisarda, E., Regan, P. H., Rotaru, F., Rudigier, M., Shand, C. M., Shearman, R., Stegemann, S., Stora, T., Sotty, Ch., Tengblad, O., Van Duppen, P., Vedia, V., Wadsworth, R., Walker, P. M., Warr, N., Wearing, F., and De Witte, H.

Published
2020

33. Competition between Allowed and First-Forbidden beta Decay : The Case of Hg-208 -> Tl-2(0)8

Author

Carroll, RJ, Podolyak, Zs, Berry, T, Grawe, H, Alexander, T, Andreyev, AN, Ansari, S, Borge, MJG, Brunet, M, Creswell, JR, Fraile, LM, Fahlander, C, Fynbo, HOU, Gamba, ER, Gelletly, W, Gerst, R-B, Gorska, M, Gredley, A, Greenlees, PT, Harkness-Brennan, LJ, Huyse, M, Judge, SM, Judson, DS, Konki, J, Kurcewicz, J, Kuti, I, Lalkovski, S, Lazarus, IH, Lica, R, Lund, M, Madurga, M, Marginean, N, Marginean, R, Marroquin, I, Mihai, C, Mihai, RE, Nacher, E, Negret, A, Nita, C, Pascu, S, Page, RD, Patel, Z, Perea, A, Phrompao, J, Piersa, M, Pucknell, V, Rahkila, P, Rapisarda, E, Regan, PH, Rotaru, F, Rudigier, M, Shand, CM, Shearman, R, Stegemann, S, Stora, T, Sotty, Ch, Tengblad, O, Van Duppen, P, Vedia, V, Wadsworth, R, Walker, PM, Warr, N, Wearing, F, De Witte, H, and Helsinki Institute of Physics

Subjects
Science & Technology, NUCLEAR-DATA SHEETS, Physics, Physical Sciences, Physics, Multidisciplinary, SELECTION RULE, Nuclear Theory, Nuclear Experiment, 114 Physical sciences
Abstract

The β decay of ^{208}Hg into the one-proton hole, one neutron-particle _{81}^{208}Tl_{127} nucleus was investigated at CERN-ISOLDE. Shell-model calculations describe well the level scheme deduced, validating the proton-neutron interactions used, with implications for the whole of the N>126, Z

Published
2020

34. Competition between Allowed and First-Forbidden β Decay: The Case of ^{208}Hg→^{208}Tl

Author

Carroll, R. J., Podolyák, Zs., Berry, T., Grawe, H., Alexander, T., Andreyev, A. N., Ansari, S., Borge, M. J. G., Brunet, M., Creswell, J. R., Fraile, L. M., Fahlander, C., Fynbo, H. O. U., Gamba, E. R., Gelletly, W., Gerst, R.-B., Górska, M., Gredley, A., Greenlees, P. T., Harkness-Brennan, L. J., Huyse, M., Judge, S. M., Judson, D. S., Konki, J., Kurcewicz, J., Kuti, I., Lalkovski, S., Lazarus, I. H., Lică, R., Lund, M., Madurga, M., Marginean, N., Marginean, R., Marroquin, I., Mihai, C., Mihai, R. E., Nácher, E., Negret, A., Nita, C., Pascu, S., Page, R. D., Patel, Z., Perea, A., Phrompao, J., Piersa, M., Pucknell, V., Rahkila, P., Rapisarda, E., Regan, P. H., Rotaru, F., Rudigier, M., Shand, C. M., Shearman, R., Stegemann, S., Stora, T., Sotty, Ch., Tengblad, O., Van Duppen, P., Vedia, V., Wadsworth, R., Walker, P. M., Warr, N., Wearing, F., and De Witte, H.

Subjects
Nuclear Theory, Nuclear Physics - Experiment, ddc:530, Nuclear Experiment
Abstract

Physical review letters 125(19), 192501 (2020). doi:10.1103/PhysRevLett.125.192501, Published by APS, College Park, Md.

Published
2020
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35. Octupole states in Tl-207 studied through beta decay

Author

Berry, T. A., Podolyak, Zs, Carroll, R. J., Lica, R., Brown, B. A., Grawe, H., Sotty, Ch, Timofeyuk, N. K., Alexander, T., Andreyev, A. N., Ansari, S., Borge, M. J. G., Brunet, M., Cresswell, J. R., Fahlander, C., Fraile, L. M., Fynbo, H. O. U., Gamba, E., Gelletly, W., Gerst, R-B, Gorska, M., Gredley, A., Greenlees, P., Harkness-Brennan, L. J., Huyse, M., Judge, S. M., Judson, D. S., Konki, J., Kowalska, M., Kurcewicz, J., Kuti, I., Lalkovski, S., Lazarus, I., Lund, M., Madurga, M., Marginean, N., Mihai, C., Mihai, R. E., Nacher, E., Negret, A., Nae, S., Nita, C., Pascu, S., Page, R. D., Patel, Z., Perea, A., Phrompao, J., Piersa, M., Pucknell, V., Rahkila, P., Rapisarda, E., Regan, P. H., Rotaru, F., Rudigier, M., Shand, C. M., Shearman, R., Simpson, E. C., Stegemann, S., Stora, T., Tengblad, O., Turturica, A., Van Duppen, P., Vedia, V., Walker, P. M., Warr, N., Wearing, F. P., De Witte, H., and Helsinki Institute of Physics

Subjects
114 Physical sciences
Abstract

The beta decay of Hg-207 into the single-proton-hole nucleus Tl-207 has been studied through gamma-ray spectroscopy at the ISOLDE Decay Station (IDS) with the aim of identifying states resulting from coupling of the pi s(1/2)(-1), pi d(3/2)(-1) and pi h(11/2)(-1) shell model orbitals to the collective octupole vibration. Twenty-two states were observed lying between 2.6 and 4.0 MeV, eleven of which were observed for the first time, and 78 new transitions were placed. Two octupole states (s(3/2)-coupled) are identified and three more states (d(3/2)-coupled) are tentatively assigned using spin-parity inferences, while further h(11/2)-coupled states may also have been observed for the first time. Comparisons are made with state-of-the-art large-scale shell model calculations and previous observations made in this region, and systematic underestimation of the energy of the octupole vibrational states is noted. We suggest that in order to resolve the difference in predicted energies for collective and noncollective t = 1 states (t is the number of nucleons breaking the Pb-208 core), the effect of t = 2 mixing may be reduced for octupole-coupled states. The inclusion of mixing with t = 0, 2, 3 excitations is necessary to replicate all t = 1 state energies accurately.

Published
2020

36. CERN-MEDICIS: A UNIQUE FACILITY FOR THE PRODUCTION OF NONCONVENTIONAL RADIONUCLIDES FOR THE MEDICAL RESEARCH

Author

Duchemin, Charlotte, Ramos, J.P., Stora, Thierry, Aubert, Elodie, Audouin, Nadia, Barbero, Ermanno, Barozier, V., Bernardes, A.P., BERTREIX, Philippe, Boscher, A, BURNEL, D., Catherall, R., Cirilli, M., Chevalley, E., Cocolios, T. E., Comte, J., Crepieux, B., Deschamps, M., Dockx, Kristof, Dorsival, A., Fedosseev, V. N., Fernier, P., Formento-Cavaier, R., Gadelshin, V.M., Gilardoni, S., Grenard, J.L., Haddad, Ferid, Heinke, R., juif, b., Khan, M., Köster, Ulli, Lambert, L., lilli, g., lunghi, g., Marsh, B. A., Martinez Palenzuela, Y., Martins, R., Marzari, S., Menaa, N., Michel, Nathalie, Pozzi, F., Riccardi, F., riegert, j., riggaz, n., Rothe, S., Stegemann, S., Talip, Z., thiboud, j., van der meulen, n. p., Vollaire, J., vuong, n. t., Wendt, Klaus, Wilkins, S., European Organization for Nuclear Research (CERN), Catholic University of Leuven - Katholieke Universiteit Leuven (KU Leuven), ARRONAX - (GIP) Groupement d'Intérêt Public [Saint-Herblain] (Institut de Recherche Public), Johannes Gutenberg - Universität Mainz (JGU), Ural Federal University [Ekaterinburg] (UrFU), Laboratoire de physique subatomique et des technologies associées (SUBATECH), Université de Nantes - UFR des Sciences et des Techniques (UN UFR ST), Université de Nantes (UN)-Université de Nantes (UN)-Centre National de la Recherche Scientifique (CNRS)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-IMT Atlantique Bretagne-Pays de la Loire (IMT Atlantique), Institut Mines-Télécom [Paris] (IMT)-Institut Mines-Télécom [Paris] (IMT), Pakistan Institute of Nuclear Science and Technology (PINSTECH), PINSTECH, Institut Laue-Langevin (ILL), ILL, and Paul Scherrer Institute (PSI)

Subjects
MC8: Applications of Accelerators, Technology Transfer, Industrial Relations and Outreach, [PHYS.HEXP]Physics [physics]/High Energy Physics - Experiment [hep-ex], Accelerators and Storage Rings, ComputingMilieux_MISCELLANEOUS, Accelerator Physics
Abstract

The MEDICIS facility is a unique facility located at CERN dedicated to the production of non-conventional radionuclides for research and development in imaging, diagnostics and radiation therapy. It exploits in a Class A work sector, a dedicated isotope separator beam line, a target irradiation station at the 1.4 GeV Proton Synchroton Booster (PSB) and receives activated targets from external institutes during CERN Long Shut-Downs. The target is heated up at high temperatures to allow for the diffusion and effusion of the atoms out of the target that are subsequently ionized. The ions are accelerated and sent through an off-line mass separator. The radionuclide of interest is extracted through mass separation and implanted into a thin metallic collection foil. After collection, the batch is prepared to be dispatched to a research center. In the near-future, the radiochemistry process will also be performed in MEDICIS. Since its commissioning in December 2017, the facility has provided novel radionuclides such as Tb-149, Tb-155, Tm-165, Er-169 and Yb-175 with high specific activity, some for the first time, to European research institutes part of the collaboration., Proceedings of the 11th International Particle Accelerator Conference, IPAC2020, Caen, France

Published
2020
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39. Competition between Allowed and First-Forbidden β Decay: The Case of Hg208→Tl208

Author

Carroll, R. J., primary, Podolyák, Zs., additional, Berry, T., additional, Grawe, H., additional, Alexander, T., additional, Andreyev, A. N., additional, Ansari, S., additional, Borge, M. J. G., additional, Brunet, M., additional, Creswell, J. R., additional, Fraile, L. M., additional, Fahlander, C., additional, Fynbo, H. O. U., additional, Gamba, E. R., additional, Gelletly, W., additional, Gerst, R.-B., additional, Górska, M., additional, Gredley, A., additional, Greenlees, P. T., additional, Harkness-Brennan, L. J., additional, Huyse, M., additional, Judge, S. M., additional, Judson, D. S., additional, Konki, J., additional, Kurcewicz, J., additional, Kuti, I., additional, Lalkovski, S., additional, Lazarus, I. H., additional, Lică, R., additional, Lund, M., additional, Madurga, M., additional, Marginean, N., additional, Marginean, R., additional, Marroquin, I., additional, Mihai, C., additional, Mihai, R. E., additional, Nácher, E., additional, Negret, A., additional, Nita, C., additional, Pascu, S., additional, Page, R. D., additional, Patel, Z., additional, Perea, A., additional, Phrompao, J., additional, Piersa, M., additional, Pucknell, V., additional, Rahkila, P., additional, Rapisarda, E., additional, Regan, P. H., additional, Rotaru, F., additional, Rudigier, M., additional, Shand, C. M., additional, Shearman, R., additional, Stegemann, S., additional, Stora, T., additional, Sotty, Ch., additional, Tengblad, O., additional, Van Duppen, P., additional, Vedia, V., additional, Wadsworth, R., additional, Walker, P. M., additional, Warr, N., additional, Wearing, F., additional, and De Witte, H., additional

Published
2020
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40. Octupole states in Tl207 studied through β decay

Author

Berry, T. A., primary, Podolyák, Zs., additional, Carroll, R. J., additional, Lică, R., additional, Brown, B. A., additional, Grawe, H., additional, Sotty, Ch., additional, Timofeyuk, N. K., additional, Alexander, T., additional, Andreyev, A. N., additional, Ansari, S., additional, Borge, M. J. G., additional, Brunet, M., additional, Cresswell, J. R., additional, Fahlander, C., additional, Fraile, L. M., additional, Fynbo, H. O. U., additional, Gamba, E., additional, Gelletly, W., additional, Gerst, R.-B., additional, Górska, M., additional, Gredley, A., additional, Greenlees, P., additional, Harkness-Brennan, L. J., additional, Huyse, M., additional, Judge, S. M., additional, Judson, D. S., additional, Konki, J., additional, Kowalska, M., additional, Kurcewicz, J., additional, Kuti, I., additional, Lalkovski, S., additional, Lazarus, I., additional, Lund, M., additional, Madurga, M., additional, Mărginean, N., additional, Mărginean, R., additional, Marroquin, I., additional, Mihai, C., additional, Mihai, R. E., additional, Nácher, E., additional, Negret, A., additional, Nae, S., additional, Niţă, C., additional, Pascu, S., additional, Page, R. D., additional, Patel, Z., additional, Perea, A., additional, Phrompao, J., additional, Piersa, M., additional, Pucknell, V., additional, Rahkila, P., additional, Rapisarda, E., additional, Regan, P. H., additional, Rotaru, F., additional, Rudigier, M., additional, Shand, C. M., additional, Shearman, R., additional, Simpson, E. C., additional, Stegemann, S., additional, Stora, T., additional, Tengblad, O., additional, Turturica, A., additional, Van Duppen, P., additional, Vedia, V., additional, Walker, P. M., additional, Warr, N., additional, Wearing, F. P., additional, and De Witte, H., additional

Published
2020
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41. Production of intense mass separated 11C beams for PET-aided hadron therapy : Productie van massa-gesepareerde 11C bundels voor PET-geassisteerde hadron therapie

Author

Stegemann, S, Cocolios, TE, Dockx, K, Leinders, G, Popescu, L, Ramos, JP, Rijpstra, K, Stora, T, Verwerft, M, Vleugels, J, and Cocolios, Thomas Elias

Subjects
Radioactive ion beam production, target material, C production
Abstract

A novel production system based on the Isotope Separation On-Line (ISOL) method is being developed to produce intense mass separated 11C beams for PET-aided hadron therapy. In this work, we present a systematic study of the target that was developed for optimized 11C beam production. A solid boron nitride target (BN) with approximately 21% open porosity was manufactured by spark plasma sintering to provide maximized in-target production yield with enhanced isotope release properties. Operational limitations with respect to high temperatures and oxidizing atmospheres were studied, revealing that the BN target can withstand temperatures up to 1500 °C and can be operated with a controlled O2 leak, providing O2 potentials up to −300 kJ/mol, measured at 1000 °C. A novel production system based on the Isotope Separation On-Line (ISOL) method is being developed to produce intense mass separated 11C beams for PET-aided hadron therapy. In this work, we present a systematic study of the target that was developed for optimized 11C beam production. A solid boron nitride target (BN) with approximately 21% open porosity was manufactured by spark plasma sintering to provide maximized in-target production yield with enhanced isotope release properties. Operational limitations with respect to high temperatures and oxidizing atmospheres were studied, revealing that the BN target can withstand temperatures up to 1500 °C and can be operated with a controlled O2 leak, providing O2 potentials up to −300 kJ/mol, measured at 1000 °C. ispartof: Nuclear Instruments & Methods In Physics Research Section B-Beam Interactions With Materials And Atoms vol:463 pages:403-407 ispartof: location:SWITZERLAND, CERN, Geneva nrpages: 5 status: published

Published
2020

42. Octupole states in $^{207}TI$ studied through $\beta$ decay

Author

Berry, T. A., Podolyák, Zs., Carroll, R. J., Lică, R., Brown, B. A., Grawe, Hubert, Sotty, Ch., Timofeyuk, N. K., Alexander, T., Andreyev, A. N., Ansari, S., Borge, M. J. G., Brunet, M., Cresswell, J. R., Fahlander, C., Fraile, L. M., Fynbo, H. O. U., Gamba, E., Gelletly, W., Gerst, R.-B., Górska, M., Gredley, A., Greenlees, P., Harkness-Brennan, L. J., Huyse, M., Judge, S. M., Judson, D. S., Konki, J., Kowalska, M., Kurcewicz, J., Kuti, I., Lalkovski, S., Lazarus, I., Lund, M., Madurga, M., Mărginean, N., Mărginean, R., Marroquin, I., Mihai, C., Mihai, R. E., Nácher, E., Negret, A., Nae, S., Niţă, C., Pascu, S., Page, R. D., Patel, Z., Perea, A., Phrompao, J., Piersa, M., Pucknell, V., Rahkila, P., Rapisarda, E., Regan, P. H., Rotaru, F., Rudigier, M., Shand, C. M., Shearman, R., Simpson, E. C., Stegemann, S., Stora, T., Tengblad, O., Turturica, A., Van Duppen, P., Vedia, V., Walker, P. M., Warr, N., Wearing, F. P., and De Witte, H.

Subjects
ddc:530
Abstract

Physical review / C 101(5), 054311 (2020). doi:10.1103/PhysRevC.101.054311, Published by APS, Woodbury, NY

Published
2020
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43. Octupole states in 207Tl studied through β decay

Author

Berry, T A, Podolyák, Zs, Carroll, R J, Lică, R, Brown, B A, Grawe, H, Sotty, Ch, Timofeyuk, N K, Alexander, T, Andreyev, A N, Ansari, S, Borge, M J G, Brunet, M, Cresswell, J R, Fahlander, C, Fraile, L M, Fynbo, H O U, Gamba, E, Gelletly, W, Gerst, R B, Górska, M, Gredley, A, Greenlees, P, Harkness-Brennan, L J, Huyse, M, Judge, S M, Judson, D S, Konki, J, Kowalska, M, Kurcewicz, J, Kuti, I, Lalkovski, S, Lazarus, I, Lund, M, Madurga, M, Mărginean, N, Mărginean, R, Marroquin, I, Mihai, C, Mihai, R E, Nácher, E, Negret, A, Nae, S, Niţă, C, Pascu, S, Page, R D, Patel, Z, Perea, A, Phrompao, J, Piersa, M, Pucknell, V, Rahkila, P, Rapisarda, E, Regan, P H, Rotaru, F, Rudigier, M, Shand, C M, Shearman, R, Simpson, E C, Stegemann, S, Stora, T, Tengblad, O, Turturica, A, Van Duppen, P, Vedia, V, Walker, P M, Warr, N, Wearing, F P, and De Witte, H

Subjects
nucleon distribution, Nuclear Physics - Experiment, collective levels, beta decay, ydinfysiikka, nuclear structure and decays
Abstract

The β decay of 207Hg into the single-proton-hole nucleus 207Tl has been studied through γ-ray spectroscopy at the ISOLDE Decay Station (IDS) with the aim of identifying states resulting from coupling of the πs−11/2, πd−13/2, and πh−111/2 shell model orbitals to the collective octupole vibration. Twenty-two states were observed lying between 2.6 and 4.0 MeV, eleven of which were observed for the first time, and 78 new transitions were placed. Two octupole states (s1/2-coupled) are identified and three more states (d3/2-coupled) are tentatively assigned using spin-parity inferences, while further h11/2-coupled states may also have been observed for the first time. Comparisons are made with state-of-the-art large-scale shell model calculations and previous observations made in this region, and systematic underestimation of the energy of the octupole vibrational states is noted. We suggest that in order to resolve the difference in predicted energies for collective and noncollective t=1 states (t is the number of nucleons breaking the 208Pb core), the effect of t=2 mixing may be reduced for octupole-coupled states. The inclusion of mixing with t=0,2,3 excitations is necessary to replicate all t=1 state energies accurately.

Published
2020
Full Text
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44. Competition between Allowed and First-Forbidden β Decay : The Case of Hg208→Tl208

Author

Carroll, R. J., Podolyák, Zs., Berry, T., Grawe, H., Alexander, T., Andreyev, A. N., Ansari, S., Borge, M. J. G., Brunet, M., Creswell, J. R., Fraile, L. M., Fahlander, C., Fynbo, H. O. U., Gamba, E. R., Gelletly, W., Gerst, R.-B., Górska, M., Gredley, A., Greenlees, P. T., Harkness-Brennan, L. J., Huyse, M., Judge, S. M., Judson, D. S., Konki, J., Kurcewicz, J., Kuti, I., Lalkovski, S., Lazarus, I. H., Lică, R., Lund, M., Madurga, M., Marginean, N., Marginean, R., Marroquin, I., Mihai, C., Mihai, R. E., Nácher, E., Negret, A., Nita, C., Pascu, S., Page, R. D., Patel, Z., Perea, A., Phrompao, J., Piersa, M., Pucknell, V., Rahkila, P., Rapisarda, E., Regan, P. H., Rotaru, F., Rudigier, M., Shand, C. M., Shearman, R., Stegemann, S., Stora, T., Sotty, Ch., Tengblad, O., Van Duppen, P., Vedia, V., Wadsworth, R., Walker, P. M., Warr, N., Wearing, F., and De Witte, H.

Subjects
Nuclear Theory, Nuclear Experiment, ydinfysiikka, nuclear structure and decays
Abstract

The β decay of 208Hg into the one-proton hole, one neutron-particle 20881Tl127 nucleus was investigated at CERN-ISOLDE. Shell-model calculations describe well the level scheme deduced, validating the proton-neutron interactions used, with implications for the whole of the N>126, Z

Published
2020

45. Investigation of the Delta n=0 selection rule in Gamow-Teller transitions: The beta-decay of Hg-207

Author

Berry, TA, Podolyak, Zs, Carroll, RJ, Lica, R, Grawe, H, Timofeyuk, NK, Alexander, T, Andreyev, AN, Ansari, S, Borge, MJG, Creswell, J, Fahlander, C, Fraile, LM, Fynbo, HOU, Gelletly, W, Gerst, R-B, Gorska, M, Gredley, A, Greenlees, R, Harkness-Brennan, LJ, Huyse, M, Judge, SM, Judson, DS, Konki, J, Kurcewicz, J, Kuti, I, Lalkovski, S, Lazarus, I, Lund, M, Madurga, M, Marginean, N, Marginean, R, Marroquin, I, Mihai, C, Mihai, RE, Nacher, E, Nae, S, Negret, A, Nita, C, Page, RD, Pascu, S, Patel, Z, Perea, A, Pucknell, V, Rahkila, R, Rapisarda, E, Regan, PH, Rotaru, F, Shand, CM, Simpson, EC, Sotty, Ch, Stegemann, S, Stora, T, Tengblad, O, Turturicag, A, Van Duppen, R, Vedia, V, Wadsworth, R, Walker, PM, Warr, N, Wearing, F, and De Witte, H

Published
2019

46. Investigation of the Δn = 0 selection rule in Gamow-Teller transitions : The β-decay of 207 Hg

Author

Berry, T. A., Podolyák, Zs, Carroll, R. J., Lică, R., Grawe, H., Timofeyuk, N. K., Alexander, T., Andreyev, A. N., Ansari, S., Borge, M. J.G., Creswell, J., Fahlander, C., Fraile, L. M., Fynbo, H. O.U., Gelletly, W., Gerst, R. B., Górska, M., Gredley, A., Greenlees, P., Harkness-Brennan, L. J., Huyse, M., Judge, S. M., Judson, D. S., Konki, J., Kurcewicz, J., Kuti, I., Lalkovski, S., Lazarus, I., Lund, M., Madurga, M., Mărginean, N., Mărginean, R., Marroquin, I., Mihai, C., Mihai, R. E., Nácher, E., Nae, S., Negret, A., Niţă, C., Page, R. D., Pascu, S., Patel, Z., Perea, A., Pucknell, V., Rahkila, P., Rapisarda, E., Regan, P. H., Rotaru, F., Shand, C. M., Simpson, E. C., Sotty, Ch, Stegemann, S., Stora, T., Tengblad, O., Turturica, A., Van Duppen, P., Vedia, V., Wadsworth, R., Walker, P. M., Warr, N., Wearing, F., and De Witte, H.

Abstract

Gamow-Teller β decay is forbidden if the number of nodes in the radial wave functions of the initial and final states is different. This Δn=0 requirement plays a major role in the β decay of heavy neutron-rich nuclei, affecting the nucleosynthesis through the increased half-lives of nuclei on the astrophysical r-process pathway below both Z=50 (for N>82) and Z=82 (for N>126). The level of forbiddenness of the Δn=1ν1g 9/2 →π0g 7/2 transition has been investigated from the β − decay of the ground state of 207 Hg into the single-proton-hole nucleus 207 Tl in an experiment at the ISOLDE Decay Station. From statistical observational limits on possible γ-ray transitions depopulating the π0g 7/2 −1 state in 207 Tl, an upper limit of 3.9×10 −3 % was obtained for the probability of this decay, corresponding to log⁡ft>8.8 within a 95% confidence limit. This is the most stringent test of the Δn=0 selection rule to date.

Published
2019

47. Competition between Allowed and First-Forbidden beta Decay: The Case of Hg-208 -> Tl-2(0)8

Author

Carroll, R. J., Podolyak, Zs, Berry, T., Grawe, H., Alexander, T., Andreyev, A. N., Ansari, S., Borge, M. J. G., Brunet, M., Creswell, J. R., Fraile, L. M., Fahlander, C., Fynbo, H. O. U., Gamba, E. R., Gelletly, W., Gerst, R-B, Gorska, M., Gredley, A., Greenlees, P. T., Harkness-Brennan, L. J., Huyse, M., Judge, S. M., Judson, D. S., Konki, J., Kurcewicz, J., Kuti, I, Lalkovski, S., Lazarus, I. H., Lica, R., Lund, M., Madurga, M., Marginean, N., Marginean, R., Marroquin, I, Mihai, C., Mihai, R. E., Nacher, E., Negret, A., Nita, C., Pascu, S., Page, R. D., Patel, Z., Perea, A., Phrompao, J., Piersa, M., Pucknell, V, Rahkila, P., Rapisarda, E., Regan, P. H., Rotaru, F., Rudigier, M., Shand, C. M., Shearman, R., Stegemann, S., Stora, T., Sotty, Ch, Tengblad, O., Van Duppen, P., Vedia, V., Wadsworth, R., Walker, P. M., Warr, N., Wearing, F., De Witte, H., Carroll, R. J., Podolyak, Zs, Berry, T., Grawe, H., Alexander, T., Andreyev, A. N., Ansari, S., Borge, M. J. G., Brunet, M., Creswell, J. R., Fraile, L. M., Fahlander, C., Fynbo, H. O. U., Gamba, E. R., Gelletly, W., Gerst, R-B, Gorska, M., Gredley, A., Greenlees, P. T., Harkness-Brennan, L. J., Huyse, M., Judge, S. M., Judson, D. S., Konki, J., Kurcewicz, J., Kuti, I, Lalkovski, S., Lazarus, I. H., Lica, R., Lund, M., Madurga, M., Marginean, N., Marginean, R., Marroquin, I, Mihai, C., Mihai, R. E., Nacher, E., Negret, A., Nita, C., Pascu, S., Page, R. D., Patel, Z., Perea, A., Phrompao, J., Piersa, M., Pucknell, V, Rahkila, P., Rapisarda, E., Regan, P. H., Rotaru, F., Rudigier, M., Shand, C. M., Shearman, R., Stegemann, S., Stora, T., Sotty, Ch, Tengblad, O., Van Duppen, P., Vedia, V., Wadsworth, R., Walker, P. M., Warr, N., Wearing, F., and De Witte, H.

Abstract

The beta decay of Hg-208 into the one-proton hole, one neutron-particle Tl-208(81)127 nucleus was investigated at CERN-ISOLDE. Shell-model calculations describe well the level scheme deduced, validating the proton-neutron interactions used, with implications for the whole of the N > 126, Z < 82 quadrant of neutron-rich nuclei. While both negative and positive parity states with spin 0 and 1 are expected within the Q(beta) window, only three negative parity states are populated directly in the beta decay. The data provide a unique test of the competition between allowed Gamow-Teller and Fermi, and first-forbidden beta decays, essential for the understanding of the nucleosynthesis of heavy nuclei in the rapid neutron capture process. Furthermore, the observation of the parity changing 0(+) -> 0(-)beta decay where the daughter state is core excited is unique, and can provide information on mesonic corrections of effective operators.

Published
2020

50. Evolution of E2 strength in the rare-earth isotopes Hf174,176,178,180

Author

Wiederhold, J., Werner, V., Kern, R., Pietralla, N., Bucurescu, D., Carroll, R., Cooper, N, Daniel, T., Filipescu, D., Florea, N., Gerst, R-B., Ghita, D., Gurgi, Laila, Jolie, J., Ilieva, Ralitsa, Lica, R., Marginean, N., Marginean, R., Mihai, C., Mitu, I. O., Naqvi, F., Nita, C., Rudigier, Matthias, Stegemann, S., Pascu, S., and Regan, Patrick

Abstract

Mean lifetimes of yrast states of the isotopes 174,176,178,180Hf have been measured using fast- electronic scintillation timing. Excited states of 74,176,178Hf were populated via β decay, while 180Hf was populated via Coulomb excitation. The lifetimes of the 2+ 1 and 4+ 1 states of all isotopes and the lifetimes of the 6+ 1 states of 174,178Hf were measured, using the slope and the centroid shift methods. The mean lifetime, τ (4+ 1 ) = 85(13) ps, of 178Hf has been determined for the first time. In addition, the mean lifetimes of the 2− 1 and the 3− 1 states of 176Hf have been determined. Systematic uncertainties on the evolution of data as a function of neutron number were reduced by using the same setup for all the isotopes of interest. The data are in agreement with other recent lifetime measurements where available and shows a shift of the maximum of collectivity for the Hf isotopic chain from neutron midshell at N = 104 to N = 100.

Published
2019

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