1,811 results on '"Köster, U."'
Search Results
52. Further Evidence for Shape Coexistence in Zn79m near Doubly Magic Ni78
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Nies, L., primary, Canete, L., additional, Dao, D. D., additional, Giraud, S., additional, Kankainen, A., additional, Lunney, D., additional, Nowacki, F., additional, Bastin, B., additional, Stryjczyk, M., additional, Ascher, P., additional, Blaum, K., additional, Cakirli, R. B., additional, Eronen, T., additional, Fischer, P., additional, Flayol, M., additional, Girard Alcindor, V., additional, Herlert, A., additional, Jokinen, A., additional, Khanam, A., additional, Köster, U., additional, Lange, D., additional, Moore, I. D., additional, Müller, M., additional, Mougeot, M., additional, Nesterenko, D. A., additional, Penttilä, H., additional, Petrone, C., additional, Pohjalainen, I., additional, de Roubin, A., additional, Rubchenya, V., additional, Schweiger, Ch., additional, Schweikhard, L., additional, Vilen, M., additional, and Äystö, J., additional
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- 2023
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53. Directional-polarization correlations using EXILL
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Urban, W., primary, Czerwiński, M., additional, de France, G., additional, Jentschel, M., additional, Köster, U., additional, Mutti, P., additional, Rza̧ca-Urban, T., additional, and Wiśniewski, J., additional
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- 2023
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54. Measurement of the $\beta$-asymmetry parameter of $^{67}$Cu in search for tensor type currents in the weak interaction
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Soti, G., Wauters, F., Breitenfeldt, M., Finlay, P., Herzog, P., Knecht, A., Köster, U., Kraev, I. S., Porobic, T., Prashanth, P. N., Towner, I. S., Tramm, C., Zákoucký, D., and Severijns, N.
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Nuclear Experiment - Abstract
Precision measurements at low energy search for physics beyond the Standard Model in a way complementary to searches for new particles at colliders. In the weak sector the most general $\beta$ decay Hamiltonian contains, besides vector and axial-vector terms, also scalar, tensor and pseudoscalar terms. Current limits on the scalar and tensor coupling constants from neutron and nuclear $\beta$ decay are on the level of several percent. The goal of this paper is extracting new information on tensor coupling constants by measuring the $\beta$-asymmetry parameter in the pure Gamow-Teller decay of $^{67}$Cu, thereby testing the V-A structure of the weak interaction. An iron sample foil into which the radioactive nuclei were implanted was cooled down to milliKelvin temperatures in a $^3$He-$^4$He dilution refrigerator. An external magnetic field of 0.1 T, in combination with the internal hyperfine magnetic field, oriented the nuclei. The anisotropic $\beta$ radiation was observed with planar high purity germanium detectors operating at a temperature of about 10\,K. An on-line measurement of the $\beta$ asymmetry of $^{68}$Cu was performed as well for normalization purposes. Systematic effects were investigated using Geant4 simulations. The experimental value, $\tilde{A}$ = 0.587(14), is in agreement with the Standard Model value of 0.5991(2) and is interpreted in terms of physics beyond the Standard Model. The limits obtained on possible tensor type charged currents in the weak interaction hamiltonian are -0.045 $< (C_T+C'_T)/C_A <$ 0.159 (90\% C.L.). The obtained limits are comparable to limits from other correlation measurements in nuclear $\beta$ decay and contribute to further constraining tensor coupling constants.
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- 2014
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55. The magnetic properties of $^{\rm 177}$Hf and $^{\rm 180}$Hf in the strong coupling deformed model
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Muto, S., Stone, N. J., Bingham, C. R., Stone, J. R., Walker, P. M., Audi, G., Gaulard, C., Köster, U., Nikolov, J., Nishimura, K., Ohtsubo, T., Podolyak, Z., Risegari, L., Simpson, G. S., Veskovic, M., and Walters, W. B.
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Nuclear Experiment - Abstract
This paper reports NMR measurements of the magnetic dipole moments of two high-K isomers, the 37/2$^-$, 51.4 m, 2740 keV state in $^{\rm 177}$Hf and the 8$^-$, 5.5 h, 1142 keV state in $^{\rm 180}$Hf by the method of on-line nuclear orientation. Also included are results on the angular distributions of gamma transitions in the decay of the $^{\rm 177}$Hf isotope. These yield high precision E2/M1 multipole mixing ratios for transitions in bands built on the 23/2$^+$, 1.1 s, isomer at 1315 keV and on the 9/2$^+$, 0.663 ns, isomer at 321 keV. The new results are discussed in the light of the recently reported finding of systematic dependence of the behavior of the g$_{\rm R}$ parameter upon the quasi-proton and quasi-neutron make up of high-K isomeric states in this region., Comment: 9 pages, 9 figures, accepted for publication in Physical Review C
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- 2014
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56. The 41Ar(n,y)42Ar reaction
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Sahoo R. N., Paul M., Köster U., Scott R., Tessler M., Zylstra A., Avila M. L., Dickerson C., Jayatissa H., Kohen M.S., McLain J., Pardo R.C., Rehm K. E., Tolstukhin I., Vondrasek R., Bailey T., Callahan L., Clark A., Collon P., Kashiv Y., and Nelson A.
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Physics ,QC1-999 - Abstract
The cross-section of the thermal neutron capture 41Ar(n,γ)42Ar(t1/2=32.9 y) reaction was measured by irradiating a 40Ar sample at the high-flux reactor of Institut Laue-Langevin (ILL) Grenoble, France. The signature of the two-neutron capture has been observed by measuring the growth curve and identifying the 1524.6 keV γ-lines of the shorter-lived 42K(12.4 h) β− daughter of 42Ar. Our preliminary value of the 41Ar(n,γ)42Ar thermal cross section is 240(80) mb at 25.3 meV. For the first time, direct counting of 42Ar was performed using the ultra-high sensitivity technique of noble gas accelerator mass spectrometry (NOGAMS) at Argonne National Laboratory, USA.
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- 2023
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57. Compton imaging for enhanced sensitivity (n,γ) cross section TOF experiments: Status and prospects
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Domingo-Pardo C., Babiano-Suarez V., Balibrea-Correa J., Caballero L., Ladarescu I., Lerendegui-Marco J., Tarifeño-Saldivia A., Aberle O., Alcayne V., Altieri S., Amaducci S., Andrzejewski J., Bacak M., Beltrami C., Bennett S., Bernardes A. P., Berthoumieux E., Beyer R., Boromiza M., Bosnar D., Caamaño M., Calviño F., Calviani M., Cano-Ott D., Casanovas A., Cerutti F., Cescutti G., Chiaveri E., Colombetti P., Colonna N., Console Camprini P., Cortés G., Cortés-Giraldo M. A., Cosentino L., Cristallo S., Dellmann S., Di Castro M., Di Maria S., Diakaki M., Dietz M., Dressler R., Dupont E., Durán I., Eleme Z., Fargier S., Fernández B., Fernández-Domínguez B., Finocchiaro P., Fiore S., García-Infantes F., Gawlik-Ramie˛ga A., Gervino G., Gilardoni S., González-Romero E., Guerrero C., Gunsing F., Gustavino C., Heyse J., Hillman W., Jenkins D. G., Jericha E., Junghans A., Kadi Y., Kaperoni K., Kaur G., Kimura A., Knapová I., Kokkoris M., Köster U., Krtička M., Kyritsis N., Lederer-Woods C., Lerner G., Manna A., Martínez T., Masi A., Massimi C., Mastinu P., Mastromarco M., Maugeri E. A., Mazzone A., Mendoza E., Mengoni A., Michalopoulou V., Milazzo P. M., Mucciola R., Murtas† F., Musacchio-Gonzalez E., Musumarra A., Negret A., Pérez de Rada A., Pérez-Maroto P., Patronis N., Pavón-Rodríguez J. A., Pellegriti M. G., Perkowski J., Petrone C., Pirovano E., Plaza J., Pomp S., Porras I., Praena J., Quesada J. M., Reifarth R., Rochman D., Romanets Y., Rubbia C., Sánchez-Caballero A., Sabaté-Gilarte M., Schillebeeckx P., Schumann D., Sekhar A., Smith A. G., Sosnin N. V., Stamati M. E., Sturniolo A., Tagliente G., Tarrío D., Torres-Sánchez P., Vagena E., Valenta S., Variale V., Vaz P., Vecchio G., Vescovi D., Vlachoudis V., Vlastou R., Wallner A., Woods P. J., Wright T., Zarrella R., and Žugec P.
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Physics ,QC1-999 - Abstract
Radiative neutron-capture cross sections are of pivotal importance in many fields such as nucle-osynthesis studies or innovative reactor technologies. A large number of isotopes have been measured with high accuracy, but there are still a large number of relevant isotopes whose cross sections could not be experimentally determined yet, at least with sufficient accuracy and completeness, owing to limitations in detection techniques, sample production methods or in the facilities themselves. In the context of the HYMNS (High-sensitivitY Measurements of key stellar Nucleo-Synthesis reactions) project over the last six years we have developed a novel detection technique aimed at background suppression in radiative neutron-capture time-of-flight measurements. This new technique utilizes a complex detection set-up based on position-sensitive radiation-detectors deployed in a Compton-camera array configuration. The latter enables to implement gamma-ray imaging techniques, which help to disentangle true capture events arising from the sample under study and contaminant background events from the surroundings. A summary on the main developments is given in this contribution together with an update on recent experiments at CERN n_TOF and an outlook on future steps.
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- 2023
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58. New measurement of the 235U(nth,f) fission yields and development of a Time of Flight line at the LOHENGRIN spectrometer
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Houdouin-Quenault M., Sage C., Méplan O., Ramdhane M., Dauvergne D., Gallin-Martel M.L., Muraz J.F., Guillaudin O., Marcatili S., Kessedjian G., Chebboubi A., Serot O., Litaize O., Bernard D., Köster U., Kim Y.H., Mutti P., and Smith A.G.
- Subjects
Physics ,QC1-999 - Abstract
The study of nuclear fission yields has a major impact on the characterization and understanding of the fission process and is mandatory for reactor applications. In the framework of a collaboration between the CEA, the LPSC and the ILL, a program of actinide fission yield measurements has been ongoing for several years at the LOHENGRIN spectrometer. However, the measurement of very low fission yields in the symmetry region and the heavy wing of the distributions is difficult to achieve due to the strong contamination by other masses with much higher yields and requires the development of a new experimental setup. This paper will first present the results of a new absolute measurement of the 235U(nth,f) mass yields using an ionization chamber placed at the exit of the spectrometer. Although very well documented in the literature, these yields show uncertainties lying from 3% to 10% with large discrepancies between libraries and a lack of correlation matrices. New experimental data obtained at the LOHENGRIN spectrometer will be detailed, along with the measurement method and the production of the experimental covariance matrix. The second part will show the development of a Time of Flight (ToF) line in order to improve the background rejection in the mass yield measurements. In the symmetry region, the precision of the measurement is limited by the background estimation due to the charge exchanges with the residual gas of the separator. We plan to analyze the events using a triple coincidence (∆E x E) x ToF, whereas today only (∆E x E) selection is available. The new ToF line is built using Si3N4 foils and secondary electron detectors (SED) for the start and stop detectors. We will present the choices made for the SED technology along with the progress achieved on the ToF line characterization.
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- 2023
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59. 40Ar proposed as probe of neutron-induced reactions in a high-density stellar-like plasma at the National Ignition Facility
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Paul M., Sahoo R. N., Tessler M., Jeet J., Velsko C., Zylstra A., Avila M., Dickerson C., Fougères C., Jayatissa H., Pardo R. C., Rehm K. E., Scott R., Tolstukhin I., Vondrasek R., Bailey T., Callahan L., Clark A. M., Collon P., Kashiv Y., Nelson A., Köster U., Hoffmann H. F. R., Pichotta M., Zuber K., Döring T., and Schwengner R.
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Physics ,QC1-999 - Abstract
The thermodynamical conditions and the neutron density produced in a laser-induced implosion of a deuterium-tritium (DT) filled capsule at the National Ignition Facility (NIF) are the closest laboratory analog of stellar conditions. We plan to investigate neutron-induced reactions on 40Ar, namely the 40Ar(n, 2n)39Ar(t1/2 =268 y), the 40Ar(n, γ)41Ar(110 min) and the potential rapid two-neutron capture reaction 40Ar(2n, γ)42Ar(33 y) in an Ar-loaded DT capsule. The chemical inertness of noble gas Ar enables reliable collection of the reaction products.
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- 2023
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60. Measurements of 233(nth,f)U233(nth,f) fission product mass yields with the LOHENGRIN recoil mass spectrometer
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Chebboubi, A., Kessedjian, G., Serot, O., Faust, H., Köster, U., Litaize, O., Sage, C., Blanc, A., Bernard, D., Letourneau, A., Materna, T., Méplan, O., Mutti, P., Rapala, M., and Ramdhane, M.
- Published
- 2021
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61. Status of the HOLMES Experiment
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Faverzani, M., Alpert, B., Balata, M., Backer, D., Bennet, D., Bevilaqua, A., Biasotti, M., Borghesi, M., Ceruti, G., De Gerone, M., Dressler, R., Ferri, E., Fowler, J., Gallucci, G., Gard, J., Gatti, F., Giachero, A., Heinitz, S., Hilton, G., Köster, U., Lusignoli, M., Mates, J., Maugeri, E., Nisi, S., Nucciotti, A., Parodi, L., Pessina, G., Puiu, A., Ragazzi, S., Reintsema, C., Ribeiro-Gomez, M., Schmidt, D., Schumann, D., Siccardi, F., Swetz, D., Ullom, J., and Vale, L.
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- 2020
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62. The Future of Neutrino Mass Measurements: Terrestrial, Astrophysical, and Cosmological Measurements in the Next Decade. Highlights of the NuMass 2013 Workshop. Milano, Italy, February 4 - 7, 2013
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Barker, G. J., Biassoni, M., De Rujula, A., De Vega, H. J., Engle, J. W., Faverzani, M., Ferri, E., Formaggio, J., Gastaldo, L., Gatti, F., Gorla, P., Köster, U., Lahiri, S., Lusignoli, M., Nucciotti, A., Ota, T., Sisti, M., Sorel, M., Terranova, F., Vissani, F., Wandkowsky, N., and Yoshimura, M.
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High Energy Physics - Experiment ,Physics - Instrumentation and Detectors - Abstract
The third Workshop of the NuMass series ("The Future of Neutrino Mass Measurements: Terrestrial, Astrophysical, and Cosmological Measurements in the Next Decade: NuMass 2013") was held at Dipartimento di Fisica "G. Occhialini, University of Milano-Bicocca in Milano, Italy, on 4-7 February 2013. The goal of this international workshop was to review the status and future of direct and indirect neutrino mass measurements in the laboratory as well as from astrophysical and cosmological observations. This paper collects most of the contributions presented during the Workshop.
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- 2013
63. Medical Application Studies at ELI-NP
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Habs, D., Thirolf, P. G., Lang, C., Jentschel, M., Köster, U., Negoita, F., and Zamfir, V.
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Nuclear Experiment - Abstract
We study the production of radioisotopes for nuclear medicine in (gamma,gamma') photoexcitation reactions or (gamma,xn + yp) photonuclear reactions for the examples of ^195mPt, ^117mSn and ^44Ti with high flux [(10^13 - 10^15) gamma/s], small beam diameter and small energy band width (Delta E/E ~ 10^-3 -10^-4) gamma beams. In order to realize an optimum gamma-focal spot, a refractive gamma-lens consisting of a stack of many concave micro-lenses will be used. It allows for the production of a high specific activity and the use of enriched isotopes. For photonuclear reactions with a narrow gamma beam, the energy deposition in the target can be reduced by using a stack of thin target wires, hence avoiding direct stopping of the Compton electrons and e^+e^- pairs. The well-defined initial excitation energy of the compound nucleus leads to a small number of reaction channels and enables new combinations of target isotope and final radioisotope. The narrow-bandwidth gamma excitation may make use of collective resonances in gamma-width, leading to increased cross sections. (gamma,gamma') isomer production via specially selected gamma cascades allows to produce high specific activity in multiple excitations, where no back-pumping of the isomer to the ground state occurs. The produced isotopes will open the way for completely new clinical applications of radioisotopes. For example ^195mPt could be used to verify the patient's response to chemotherapy with platinum compounds before a complete treatment is performed. In targeted radionuclide therapy the short-range Auger and conversion electrons of ^195mPt and ^117mSn enable a very local treatment. The generator ^44Ti allows for a PET with an additional gamma-quantum (gamma-PET), resulting in a reduced dose or better spatial resolution., Comment: 10 pages, 7 figures
- Published
- 2012
64. Identification of the slow E3 transition 136mCs -> 136Cs with conversion electrons
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Wimmer, K., Koester, U., Hoff, P., Kroell, Th., Kruecken, R., Lutter, R., Mach, H., Morgan, Th., Sarkar, S., Sarkar, M. Saha, Schwerdtfeger, W., Srivastava, P. C., Thirolf, P. G., and Van Isacker, P.
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Nuclear Experiment ,Nuclear Theory - Abstract
We performed at ISOLDE the spectroscopy of the decay of the 8- isomer in 136Cs by and conversion-electron detection. For the first time the excitation energy of the isomer and the multipolarity of its decay have been measured. The half-life of the isomeric state was remeasured to T1/2 = 17.5(2) s. This isomer decays via a very slow 518 keV E3 transition to the ground state. In addition to this, a much weaker decay branch via a 413 keV M4 and a subsequent 105 keV E2 transition has been found. Thus we have found a new level at 105 keV with spin 4+ between the isomeric and the ground state. The results are discussed in comparison to shell model calculations., Comment: Phys. Rev. C accepted for publication
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- 2011
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65. Coulomb excitation of 73Ga
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Diriken, J., Stefanescu, I., Balabanski, D., Blasi, N., Blazhev, A., Bree, N., Cederkäll, J., Cocolios, T. E., Davinson, T., Eberth, J., Ekström, A., Fedorov, D. V., Fedosseev, V. N., Fraile, L. M., Franchoo, S., Georgiev, G., Gladnishki, K., Huyse, M., Ivanov, O. V., Ivanov, V. S., Iwanicki, J., Jolie, J., Konstantinopoulos, T., Kröll, Th., Krücken, R., Köster, U., Lagoyannis, A., Bianco, G. Lo, Maierbeck, P., Marsh, B. A., Napiorkowski, P., Patronis, N., Pauwels, D., Reiter, P., Seliverstov, M., Sletten, G., Van de Walle, J., Van Duppen, P., Voulot, D., Walters, W. B., Warr, N., Wenander, F., and Wrzosek, K.
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Nuclear Experiment - Abstract
The B(E2; Ii -> If) values for transitions in 71Ga and 73Ga were deduced from a Coulomb excitation experiment at the safe energy of 2.95 MeV/nucleon using post-accelerated beams of 71,73Ga at the REX-ISOLDE on-line isotope mass separator facility. The emitted gamma rays were detected by the MINIBALL-detector array and B(E2; Ii->If) values were obtained from the yields normalized to the known strength of the 2+ -> 0+ transition in the 120Sn target. The comparison of these new results with the data of less neutron-rich gallium isotopes shows a shift of the E2 collectivity towards lower excitation energy when adding neutrons beyond N = 40. This supports conclusions from previous studies of the gallium isotopes which indicated a structural change in this isotopical chain between N = 40 and N = 42. Combined with recent measurements from collinear laser spectroscopy showing a 1/2- spin and parity for the ground state, the extracted results revealed evidence for a 1/2-; 3/2- doublet near the ground state in 73 31Ga42 differing by at most 0.8 keV in energy.
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- 2010
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66. Production of Medical Radioisotopes with High Specific Activity in Photonuclear Reactions with $\gamma$ Beams of High Intensity and Large Brilliance
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Habs, D. and Köster, U.
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Physics - Medical Physics ,Nuclear Experiment - Abstract
We study the production of radioisotopes for nuclear medicine in $(\gamma,x{\rm n}+y{\rm p})$ photonuclear reactions or ($\gamma,\gamma'$) photoexcitation reactions with high flux [($10^{13}-10^{15}$)$\gamma$/s], small diameter $\sim (100 \, \mu$m$)^2$ and small band width ($\Delta E/E \approx 10^{-3}-10^{-4}$) $\gamma$ beams produced by Compton back-scattering of laser light from relativistic brilliant electron beams. We compare them to (ion,$x$n$ + y$p) reactions with (ion=p,d,$\alpha$) from particle accelerators like cyclotrons and (n,$\gamma$) or (n,f) reactions from nuclear reactors. For photonuclear reactions with a narrow $\gamma$ beam the energy deposition in the target can be managed by using a stack of thin target foils or wires, hence avoiding direct stopping of the Compton and pair electrons (positrons). $(\gamma,\gamma')$ isomer production via specially selected $\gamma$ cascades allows to produce high specific activity in multiple excitations, where no back-pumping of the isomer to the ground state occurs. We discuss in detail many specific radioisotopes for diagnostics and therapy applications. Photonuclear reactions with $\gamma$ beams allow to produce certain radioisotopes, e.g. $^{47}$Sc, $^{44}$Ti, $^{67}$Cu, $^{103}$Pd, $^{117m}$Sn, $^{169}$Er, $^{195m}$Pt or $^{225}$Ac, with higher specific activity and/or more economically than with classical methods. This will open the way for completely new clinical applications of radioisotopes. For example $^{195m}$Pt could be used to verify the patient's response to chemotherapy with platinum compounds before a complete treatment is performed. Also innovative isotopes like $^{47}$Sc, $^{67}$Cu and $^{225}$Ac could be produced for the first time in sufficient quantities for large-scale application in targeted radionuclide therapy., Comment: submitted to Appl. Phys. B
- Published
- 2010
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67. Magnetic moment of Ag-104(m) and the hyperfine magnetic field of Ag in Fe using nuclear magnetic resonance on oriented nuclei
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Golovko, V. V., Kraev, I. S., Phalet, T., Delaure, B., Beck, M., Kozlov, V. Yu., Coeck, S., Wauters, F., Herzog, P., Tramm, Ch., Zakoucky, D., Venos, D., Srnka, D., Honusek, M., Koester, U., and Severijns, N.
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Nuclear Experiment - Abstract
Nuclear magnetic resonance (NMR/ON) measurements with beta- and gamma-ray detection have been performed on oriented Ag-104(g,m) nuclei with the NICOLE He-3-He-4 dilution refrigerator setup at ISOLDE/CERN. For Ag-104(g) (I-pi = 5(+)) the gamma-NMR/ON resonance signal was found at nu = 266.70(5) MHz. Combining this result with the known magnetic moment for this isotope, the magnetic hyperfine field of Ag impurities in an Fe host at low temperature (< 1 K) is found to be vertical bar B-hf(AgFe)vertical bar = 44.709(35) T. A detailed analysis of other relevant data available in the literature yields three more values for this hyperfine field. Averaging all four values yields a new and precise value for the hyperfine field of Ag in Fe; that is, vertical bar B-hf(AgFe)vertical bar = 44.692(30) T. For Ag-104(m) (I-pi = 2(+)), the anisotropy of the beta particles provided the NMR/ON resonance signal at nu = 627.7(4) MHz. Using the new value for the hyperfine field of Ag in Fe, this frequency corresponds to the magnetic moment mu(Ag-104m) = +3.691(3) mu(N), which is significantly more precise than previous results. The magnetic moments of the even-A Ag102 -110 isotopes are discussed in view of the competition between the (pi g(9/2))(7/2+)(-3)(nu d(5/2)nu g(7/2))(5/2+) and the (pi g(9/2))(9/2+)(-3)(nu d(5/2)nu g(7/2))(5/2+) configurations. The magnetic moments of the ground and isomeric states of Ag-104 can be explained by an almost complete mixing of these two configurations., Comment: 12 pages, 7 figures
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- 2010
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68. beta-decay study of Cu-77
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Patronis, N., De Witte, H., Gorska, M., Huyse, M., Kruglov, K., Pauwels, D., Van de Vel, K., Van Duppen, P., Van Roosbroeck, J., Thomas, J. -C., Franchoo, S., Cederkall, J., Fedoseyev, V. N., Fynbo, H., Georg, U., Jonsson, O., Köster, U., Materna, T., Mathieu, L., Serot, O., Weissman, L., Mueller, W. F., Mishin, V. I., and Fedorov, D.
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Nuclear Experiment - Abstract
A beta-decay study of Cu-77 has been performed at the ISOLDE mass separator with the aim to deduce its beta-decay properties and to obtain spectroscopic information on Zn-77. Neutron-rich copper isotopes were produced by means of proton- or neutron-induced fission reactions on U-238. After the production, Cu-77 was selectively laser ionized, mass separated and sent to different detection systems where beta-gamma and beta-n coincidence data were collected. We report on the deduced half-live, decay scheme, and possible spin assignment of 77Cu.
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- 2009
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69. Synthesis and preclinical evaluation of BOLD-100 radiolabeled with ruthenium-97 and ruthenium-103.
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Happl, B., Balber, T., Heffeter, P., Denk, C., Welch, J. M., Köster, U., Alliot, C., Bonraisin, A.-C., Brandt, M., Haddad, F., Sterba, J. H., Kandioller, W., Mitterhauser, M., Hacker, M., Keppler, B. K., and Mindt, T. L.
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CHOLANGIOCARCINOMA ,GASTRIC mucosa ,RADIOACTIVE tracers ,AUTORADIOGRAPHY ,DIAGNOSTIC imaging ,SINGLE-photon emission computed tomography - Abstract
BOLD-100 (formerly IT-139, KP1339), a well-established chemotherapeutic agent, is currently being investigated in clinical trials for the treatment of gastric, pancreatic, colorectal, and bile duct cancer. Despite numerous studies, the exact mode of action is still the subject of discussions. Radiolabeled BOLD-100 could be a powerful tool to clarify pharmacokinetic pathways of the compound and to predict therapy responses in patients using nuclear molecular imaging prior to the therapy. In this study, the radiosyntheses of carrier-added (c.a.) [
97/103 Ru]BOLD-100 were performed with the two ruthenium isotopes ruthenium-103 (103 Ru; β− , γ) and ruthenium-97 (97 Ru; EC, γ), of which in particular the latter isotope is suitable for imaging by single-photon emission computed tomography (SPECT). To identify the best tumor-to-background ratio for diagnostic imaging, biodistribution studies were performed with two different injected doses of c.a. [103 Ru]BOLD-100 (3 and 30 mg kg−1 ) in Balb/c mice bearing CT26 allografts over a time period of 72 h. Additionally, ex vivo autoradiography of the tumors (24 h p.i.) was conducted. Our results indicate that the higher injected dose (30 mg kg−1 ) leads to more unspecific accumulation of the compound in non-targeted tissue, which is likely due to an overload of the albumin transport system. It was also shown that lower amounts of injected c.a. [103 Ru]BOLD-100 resulted in a relatively higher tumor uptake and, therefore, a better tumor-to-background ratio, which are encouraging results for future imaging studies using c.a. [97 Ru]BOLD-100. [ABSTRACT FROM AUTHOR]- Published
- 2024
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70. Lifetime measurements in Nb99 and Zr99 : Investigation of shape coexistence
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Pfeil, A., primary, Nomura, K., additional, Gavrielov, N., additional, Régis, J.-M., additional, Köster, U., additional, Kim, Y. H., additional, Esmaylzadeh, A., additional, Harter, A., additional, Jolie, J., additional, Knafla, L., additional, Ley, M., additional, and Karayonchev, V., additional
- Published
- 2023
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71. Lifetime measurements in 131Sb at LOHENGRIN
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Bottoni, S., primary, Gamba, E. R., additional, De Gregorio, G., additional, Gargano, A., additional, Leoni, S., additional, Fornal, B., additional, Brancadori, N., additional, Ciconali, G., additional, Crespi, F. C. L., additional, Cieplicka-Oryńczak, N., additional, Iskra, Ł. W., additional, Colombi, G., additional, Kim, Y.H., additional, Köster, U., additional, Michelagnoli, C., additional, Dunkel, F., additional, Esmaylzadeh, A., additional, Gerhard, L., additional, Jolie, J., additional, Knafla, L., additional, Ley, M., additional, Régis, J.-M., additional, Schomaker, K., additional, and Sferrazza, M., additional
- Published
- 2023
- Full Text
- View/download PDF
72. Structure of N=56 isotones with 36≤Z≤42 protons
- Author
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Wiśniewski, J., primary, Urban, W., additional, Rząca-Urban, T., additional, Sieja, K., additional, Blanc, A., additional, Jentschel, M., additional, Micheagnoli, C., additional, Mutti, P., additional, Köster, U., additional, de France, G., additional, Simpson, G. S., additional, and Ur, C. A., additional
- Published
- 2023
- Full Text
- View/download PDF
73. In-source and in-trap formation of molecular ions in the actinide mass range at CERN-ISOLDE
- Author
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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
- Full Text
- View/download PDF
74. Shape coexistence near the neutron number N=20: First identification of the E0 decay from the deformed 0^+_2 state in 30Mg
- Author
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Schwerdtfeger, W., Thirolf, P. G., Wimmer, K., Habs, D., Mach, H., Rodriguez, T. R., Bildstein, V., Egido, J. L., Fraile, L. M., Gernhaeuser, R., Hertenberger, R., Heyde, K., Hoff, P., Huebel, H., Koester, U., Kroell, T., Kruecken, R., Lutter, R., Morgan, T., and Ring, P.
- Subjects
Nuclear Experiment - Abstract
The 1789 keV level in 30Mg was identified as the first excited 0^+ state by measuring its E0 transition to the ground state. The measured small value of rho^2(E0,0^+_2 --> 0^+_1) = 5.7(14) x 10^-3 implies a very small mixing of competing configurations with largely different intrinsic quadrupole deformation near N=20. Axially symmetric Beyond-Mean-Field configuration mixing calculations identify the ground state of 30Mg to be based on neutron configurations below the N=20 shell closure, while the excited 0^+ state mainly consists of a two neutrons excitated into the nu1 f_{7/2} orbital. Using a two-level model, a mixing amplitude of 0.08(4) can be derived., Comment: 4 pages, 4 figures, submitted to Physical Review Letters
- Published
- 2008
- Full Text
- View/download PDF
75. Coulomb excitation of $^{68}$Ni at safe energies
- Author
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Bree, N., Stefanescu, I., Butler, P. A., Cederkäll, J., Davinson, T., Delahaye, P., Eberth, J., Fedorov, D., Fedosseev, V. N., Fraile, L. M., Franchoo, S., Georgiev, G., Gladnishki, K., Huyse, M., Ivanov, O., Iwanicki, J., Jolie, J., Köster, U., Kröll, Th., Krücken, R., Marsh, B. A., Niedermaier, O., Reiter, P., Scheit, H., Schwalm, D., Sieber, T., Van de Walle, J., Van Duppen, P., Warr, N., Weisshaar, D., Wenander, F., and Zemlyanoy, S.
- Subjects
Nuclear Experiment - Abstract
The $B(E2;0^+\to2^+)$ value in $^{68}$Ni has been measured using Coulomb excitation at safe energies. The $^{68}$Ni radioactive beam was post-accelerated at the ISOLDE facility (CERN) to 2.9 MeV/u. The emitted $\gamma$ rays were detected by the MINIBALL detector array. A kinematic particle reconstruction was performed in order to increase the measured c.m. angular range of the excitation cross section. The obtained value of 2.8$^{+1.2}_{-1.0}$ 10$^2$ e$^2$fm$^4$ is in good agreement with the value measured at intermediate energy Coulomb excitation, confirming the low $0^+\to2^+$ transition probability., Comment: 4 pages, 5 figures
- Published
- 2008
- Full Text
- View/download PDF
76. Confirmation of Parity Violation in the Gamma Decay of $^{180}Hf^{m}$
- Author
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Stone, J. R., Goldring, G., Stone, N. J., Severijns, N., Hass, M., Zakoucky, D., Giles, T., Köster, U., Kraev, I. S., Lakshmi, S., Lindroos, M., and Wauters, F.
- Subjects
Nuclear Experiment - Abstract
This paper reports measurements using the technique of On Line Nuclear Orientation (OLNO) which reexamine the gamma decay of isomeric $^{\rm 180}$Hf$^{\rm m}$ and specifically the 501 keV 8$^{\rm -}$ -- 6$^{\rm +}$ transition. The irregular admixture of E2 to M2/E3 multipolarity in this transition, deduced from the forward-backward asymmetry of its angular distribution, has for decades stood as the prime evidence for parity mixing in nuclear states. The experiment, based on ion implantation of the newly developed mass-separated $^{\rm 180}$Hf$^{\rm m}$ beam at ISOLDE, CERN into an iron foil maintained at millikelvin temperatures, produces higher degrees of polarization than were achieved in previous studies of this system. The value found for the E2/M2 mixing ratio, $\epsilon$ = -0.0324(16)(17), is in close agreement with the previous published average value $\epsilon$ = - 0.030(2), in full confirmation of the presence of the irregular E2 admixture in the 501 keV transition. The temperature dependence of the forward-backward asymmetry has been measured over a more extended range of nuclear polarization than previously possible, giving further evidence for parity mixing of the 8$^{\rm -}$ and 8$^{\rm +}$ levels and the deduced E2/M2 mixing ratio., Comment: 28 pages, 9 figures, accepted for publication in Physical Review C
- Published
- 2007
- Full Text
- View/download PDF
77. Precision Measurement of the Decay Rate of 7Be in Host Materials
- Author
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Nir-El, Y., Haquin, G., Yungreiss, Z., Hass, M., Goldring, G., Chamoli, S. K., Singh, B. S. Nara, Lakshmi, S., Koester, U., Champault, N., Dorsival, A., Georgiev, G., Fedoseyev, V. N., Marsh, B. A., Schumann, D., Heidenreich, G., and Teichmann, S.
- Subjects
Nuclear Experiment - Abstract
A controlled and precise determination of the cross-sections of the fusion reactions 7Be(p,gamma)8B and 3He(4He,gamma)7Be, which play an important role in determining the solar neutrino flux, necessitates the knowledge of a precise value of the electron-capture half-life of 7Be. This half-life may depend on the material hosting the 7Be atoms via small modifications of the electron density around the 7Be nucleus. In this brief communication we report on the measurement of 7Be implanted in four materials: copper, aluminum, sapphire and PVC. The four results are consistent with a null host dependence within two standard deviations and their weighted average of 53.236(39)d agrees very well with the adopted value in the literature, 53.22(6)d. The present results may exhibit a slight (0.22%) increase of the half-life at room temperature for metals compared to insulators that requires further studies., Comment: 4 pages, 4 figures. Accepted for publication in Phys. Rev. C (Rapid Communications)
- Published
- 2006
- Full Text
- View/download PDF
78. A new detector system for the measurement of high-energy prompt [formula omitted]-rays for low-energy neutron induced fission
- Author
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Makii, H., Nishio, K., Hirose, K., Orlandi, R., Léguillon, R., Ogawa, T., Soldner, T., Hambsch, F.-J., Aïche, M., Astier, A., Czajkowski, S., Frost, R., Guo, S., Köster, U., Mathieu, L., Ohtsuki, T., Petrache, C.M., Pollitt, A., Sekimoto, S., Takamiya, K., and Tsekhanovich, I.
- Published
- 2018
- Full Text
- View/download PDF
79. A new methodology for studying neutron absorber materials: First results with boron carbide
- Author
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Desgranges, L., Escleine, J.M., Bienvenu, Ph., Roure, I., Gosset, D., Boffy, R., and Köster, U.
- Published
- 2018
- Full Text
- View/download PDF
80. Preparation and characterization of three 7Be targets for the measurement of the 7Be(n, p)7Li and 7Be(n, [formula omitted])7Li reaction cross sections
- Author
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Maugeri, E.A., Heinitz, S., Dressler, R., Barbagallo, M., Ulrich, J., Schumann, D., Colonna, N., Köster, U., Ayranov, M., Vontobel, P., Mastromarco, M., Schell, J., Correia, J. Martins, and Stora, T.
- Published
- 2018
- Full Text
- View/download PDF
81. The acceleration and storage of radioactive ions for a neutrino factory
- Author
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Autin, B., Benedikt, M., Hancock, S., Haseroth, H., Jansson, A., Koester, U., Lindroos, M., Russenschuck, S., Wenander, F., and Grieser, M.
- Subjects
Physics - Accelerator Physics - Abstract
The term beta-beam has been coined for the production of a pure beam of electron neutrinos or their antiparticles through the decay of radioactive ions circulating in a storage ring. This concept requires radioactive ions to be accelerated to a Lorentz gamma of 150 for 6He and 60 for 18Ne. The neutrino source itself consists of a storage ring for this energy range, with long straight sections in line with the experiment(s). Such a decay ring does not exist at CERN today, nor does a high-intensity proton source for the production of the radioactive ions. Nevertheless, the existing CERN accelerator infrastructure could be used as this would still represent an important saving for a beta-beam facility. This paper outlines the first study, while some of the more speculative ideas will need further investigations., Comment: Accepted for publication in proceedings of Nufact02, London, 2002
- Published
- 2003
- Full Text
- View/download PDF
82. A New Measurement of the Proton Capture Rate on 7Be and the S17(0) Factor
- Author
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Baby, L. T., Bordeanu, C., Goldring, G., Hass, M., Weissman, L., Fedoseyev, V. N., Koester, U., Nir-El, Y., Haquin, G., Gaggeler, H. W., Weinreich, R., and Collaboration, the ISOLDE
- Subjects
Nuclear Experiment - Abstract
The 7Be(p,gamma)8B reaction plays a central role in the evaluation of solar neutrino fluxes. We report on a new precision measurement of the cross section of this reaction, following our previous experiment with an implanted target, a raster scanned beam and the elimination of backscattering losses. The new measurement incorporates a higher activity 7Be target and a number of improvements in design and procedure. The cross section at Ec.m. = 850 keV was measured several times under varying expermental conditions, yielding a value of S17(Ec.m.=850 keV) = 24.0 +/- 0.5 eV b. Measurements were carried out at lower energies as well. We obtain from the entire set of measurements an extrapolated value of S17(0) = 21.2 +/- 0.7 eV b., Comment: Full details of the nucl-ex/0208005, PRL 90, 022501 (2003); 17 figures
- Published
- 2002
- Full Text
- View/download PDF
83. A New Precision Measurement of the 7Be(p,gamma)8B Cross section with an Implanted 7Be Target
- Author
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Baby, L. T., Bordeanu, C., Goldring, G., Hass, M., Weissman, L., Fedoseyev, V. N., Koester, U., Nir-El, Y., Haquin, G., Gaggeler, H. W., Weinreich, R., and collaboration, the ISOLDE
- Subjects
Nuclear Experiment - Abstract
The 7Be(p,gamma)8B reaction plays a central role in the evaluation of solar neutrino fluxes. We report on a new precision measurement of the cross section of this reaction, following our previous experiment with an implanted 7Be target, a raster scanned beam and the elimination of the backscattering loss. The new measurement incorporates a more abundant 7Be target and a number of improvements in design and procedure. The point at Elab=991 keV was measured several times under varying conditions, yielding a value of S17(Ec.m. =850 keV) = 24.0(5) eV b. Measurements were carried out at lower energies as well. Due to the precise knowledge of the implanted 7Be density profile it was possible to reconstitute both the off- and on resonance parts of the cross section and to obtain from the entire set of measurements an extrapolated value of S17(0)=21.2(7) eV b., Comment: 4 Pages, 3 Figures
- Published
- 2002
- Full Text
- View/download PDF
84. Conjugation, labelling and in vitro/in vivo assessment of an anti-VEGF monoclonal antibody labelled with niobium isotopes
- Author
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de la Fuente, A., Radchenko, V., Tsotakos, T., Tsoukalas, C., Paravatou-Petsotas, M., Harris, A. L., Köster, U., Rösch, F., and Bouziotis, P.
- Published
- 2018
- Full Text
- View/download PDF
85. Compton Imaging and Machine-Learning techniques for an enhanced sensitivity in key stellar (n,γ) measurements
- Author
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Lerendegui-Marco J., Babiano-Suárez V., Balibrea-Correa J., Caballero L., Calvo D., Domingo-Pardo C., Ladarescu I., Real D., Calviño F., Casanovas A., Tarifeño-Saldivia A., Alcayne V., Guerrero C., Millán-Callado M.A., Rodríguez-González T., Barbagallo M., Chiera N.M, Dressler R., Heinitz S., Maugeri E.A, Schumann D., and Köster U.
- Subjects
Physics ,QC1-999 - Abstract
Neutron capture cross-section measurements are fundamental in the study of astrophysical phenomena, such as the slow neutron capture (s-) process of nucleosynthesis operating in red-giant stars. To enhance the sensitivity of such measurements we have developed the i-TED detector. i-TED is an innovative detection system which exploits the Compton imaging technique with the aim of obtaining information about the incoming direction of the detected γ-rays. The imaging capability allows one to reject a large fraction of the dominant γ-ray background, hence enhancing the (n,γ) detection sensitivity. This work summarizes the main results of the first experimental proof-of-concept of the background rejection with i-TED carried out at CERN n_TOF using an early i-TED demonstrator. Two state-of-the-art C6D6 detectors were also used to benchmark the performance of i-TED. The i-TED prototype built for this study shows a factor of ~3 higher detection sensitivity than C6D6 detectors in the ~10 keV neutron-energy range of astrophysical interest. This works also introduces the perspectives of further enhancement in performance attainable with the final i-TED array and new analysis methodologies based on Machine-Learning techniques. The latter provide higher (n,γ) detection efficiency and similar enhancement in the sensitivity than the analytical method based on the Compton scattering law. Finally, we present our proposal to use this detection system for the first time on key astrophysical (n,γ) measurements, in particular on the s-process branching-point 79Se, which is especially well suited to constrain the thermal conditions of Red Giant and Massive Stars.
- Published
- 2022
- Full Text
- View/download PDF
86. Decay of neutron-rich Mn nuclides and deformation of heavy Fe isotopes
- Author
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Hannawald, M., Kautzsch, T., Woehr, A., Walters, W. B., Kratz, K. -L., Fedoseyev, V. N., Mishin, V. L., Boehmer, W., Pfeiffer, B., Sebastian, V., Jading, Y., Koester, U., Lettry, J., Ravn, H. L., and Collaboration, the ISOLDE
- Subjects
Nuclear Experiment - Abstract
The use of chemically selective laser ionization combined with beta-delayed neutron counting at CERN/ISOLDE has permitted identification and half-life measurements for 623-ms Mn-61 up through 14-ms Mn-69. The measured half-lives are found to be significantly longer near N=40 than the values calculated with a QRPA shell model using ground-state deformations from the FRDM and ETFSI models. Gamma-ray singles and coincidence spectroscopy has been performed for Mn-64 and Mn-66 decays to levels of Fe-64 and Fe-66, revealing a significant drop in the energy of the first 2+ state in these nuclides that suggests an unanticipated increase in collectivity near N=40., Comment: Latex-file with 4 figures, 5 pages, Phys. Rev. Lett., in print
- Published
- 1998
- Full Text
- View/download PDF
87. Low-spin excitations in Zr95
- Author
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Rząca-Urban, T., primary, Urban, W., additional, Blanc, A., additional, Jentschel, M., additional, Mutti, P., additional, Köster, U., additional, de France, G., additional, Simpson, G. S., additional, and Ur, C. A., additional
- Published
- 2023
- Full Text
- View/download PDF
88. Production of neptunium and plutonium nuclides from uranium carbide using 1.4-GeV protons
- Author
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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
- Full Text
- View/download PDF
89. Development of a liquid scintillator based active fission target for FIPPS
- Author
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Kandzia, F., Belier, G., Michelagnoli, C., Aupiais, J., Barani, M., Dudouet, J., Düllmann, Ch. E., Iskra, Ł. W., Jentschel, M., Kim, Y. H., Köster, U., and Turturica, A.
- Published
- 2020
- Full Text
- View/download PDF
90. Establishment of a clinical SPECT/CT protocol for imaging of 161Tb
- Author
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Marin, I., Rydèn, T., Van Essen, M., Svensson, J., Gracheva, N., Köster, U., Zeevaart, J. R., van der Meulen, N. P., Müller, C., and Bernhardt, P.
- Published
- 2020
- Full Text
- View/download PDF
91. GRIDSA: femtosecond lifetime measurements with germanium detector arrays
- Author
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Crespi, F. C. L., Cieplicka-Oryńczak, N., Jentschel, M., Kandzia, F., Kim, Y. H., Köster, U., Leoni, S., Michelagnoli, C., and Ziliani, S.
- Published
- 2020
- Full Text
- View/download PDF
92. High-resolution and low-background 163Ho spectrum: interpretation of the resonance tails
- Author
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Velte, C., Ahrens, F., Barth, A., Blaum, K., Braß, M., Door, M., Dorrer, H., Düllmann, Ch. E., Eliseev, S., Enss, C., Filianin, P., Fleischmann, A., Gastaldo, L., Goeggelmann, A., Goodacre, T. Day, Haverkort, M. W., Hengstler, D., Jochum, J., Johnston, K., Keller, M., Kempf, S., Kieck, T., König, C. M., Köster, U., Kromer, K., Mantegazzini, F., Marsh, B., Novikov, Yu. N., Piquemal, F., Riccio, C., Richter, D., Rischka, A., Rothe, S., Schüssler, R. X., Schweiger, Ch., Stora, T., Wegner, M., Wendt, K., Zampaolo, M., and Zuber, K.
- Published
- 2019
- Full Text
- View/download PDF
93. Measurement of the 13C(n,γ) thermal cross section via neutron irradiation and AMS
- Author
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Wright, T., Bennett, S., Heinitz, S., Köster, U., Mills, R., Soldner, T., Steier, P., Wallner, A., and Wieninger, T.
- Published
- 2019
- Full Text
- View/download PDF
94. Core-proton coupled nature of the 11/2+ state in 131 Sb probed by lifetime measurements
- Author
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Bottoni, S., primary, Gamba, E. R., additional, De Gregorio, G., additional, Gargano, A., additional, Leoni, S., additional, Fornal, B., additional, Brancadori, N., additional, Ciconali, G., additional, Crespi, F. C. L., additional, Cieplicka-Oryńczak, N., additional, Iskra, L. W., additional, Colombi, G., additional, Kim, Y.H., additional, Köster, U., additional, Michelagnoli, C., additional, Dunkel, F., additional, Esmaylzadeh, A., additional, Gerhard, L., additional, Jolie, J., additional, Knafla, L., additional, Ley, M., additional, Régis, J.-M., additional, Schomaker, K., additional, and Sferrazza, M., additional
- Published
- 2023
- Full Text
- View/download PDF
95. 40Ar proposed as probe of neutron-induced reactions in a high-density stellar-like plasma at the National Ignition Facility
- Author
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Paul, M., Sahoo, S. N., Tessler, M., Jeet, J., Velsko, C., Zylstra, A., Avila, M., Dickerson, C., Fougeres, C., Jayatissa, H., Pardo, R. C., Rehm, K. E., Scott, R., Toltsukhin, I., Vondrasek, R., Bailey, T., Callahan, L., Clark, A. M., Collon, P., Kashiv, Y., Nelson, A., Köster, U., Hoffmann, H. F. R., Pichotta, M., Zuber, K., Döring, T., (0000-0002-7620-8882) Schwengner, R., Paul, M., Sahoo, S. N., Tessler, M., Jeet, J., Velsko, C., Zylstra, A., Avila, M., Dickerson, C., Fougeres, C., Jayatissa, H., Pardo, R. C., Rehm, K. E., Scott, R., Toltsukhin, I., Vondrasek, R., Bailey, T., Callahan, L., Clark, A. M., Collon, P., Kashiv, Y., Nelson, A., Köster, U., Hoffmann, H. F. R., Pichotta, M., Zuber, K., Döring, T., and (0000-0002-7620-8882) Schwengner, R.
- Abstract
The thermodynamical conditions of plasma density, temperature, pressure and the neutron density produced in a laser-induced implosion of a deuterium-tritium (DT) filled capsule at the National Ignition Facility (NIF) are the closest laboratory analog of stellar conditions. We plan to investigate neutron-induced reactions on 40Ar, namely the 40Ar(n, 2n)39Ar(t1/2 =268 y), the 40Ar(n,gamma)41Ar(110 min) and the potential rapid two-neutron capture reaction 40Ar(2n,gamma)42Ar(33 y) in the same implosion on an Ar-loaded DT capsule. The chemical inertness of noble gas Ar enables reliable collection of the reaction products. We describe here the technique of Noble-Gas Accelerator Mass Spectrometry (NOGAMS) to be used for ultra-sensitive detection of the long-lived 39Ar and 42Ar at Argonne National Laboratory. A 42Ar(33 y) sample was produced via the slow two-neutron capture reaction 40Ar(2n, gamma)42Ar in a high thermal-neutron flux irradiation. 39Ar and for the first time 42Ar atoms were directly detected in the abundance range 10^-12 -- 10^-13 . The present sensitivity of 42Ar detection is of the order of 104 atoms.
- Published
- 2023
96. Inside HOLMES experiment: 163Ho metallic target production for the micro-calorimeter absorber
- Author
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Pizzigoni, G., Alpert, B., Balata, M., Bennett, D., Biasotti, M., Boragno, C., Brofferio, C., De Gerone, M., Dressler, R., Faverazani, M., Ferri, E., Folwer, J., Gatti, F., Giachero, A., Heinitz, S., Hilton, G., Köster, U., Lusignoli, M., Maino, M., Mates, J., Nisi, S., Nizzolo, R., Nucciotti, A., Pessina, G., Puiu, A., Ragazzi, S., Reintsema, C., Ribeiro Gomes, M., Shmidt, D., Schumann, D., Sisti, M., Swetz, D., Terranova, F., Ullom, J., and Day, P.K.
- Published
- 2016
- Full Text
- View/download PDF
97. Development of a Gas Filled Magnet spectrometer within the FIPPS project
- Author
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Chebboubi, A., Kessedjian, G., Faust, H., Blanc, A., Jentschel, M., Köster, U., Materna, T., Méplan, O., Sage, C., and Serot, O.
- Published
- 2016
- Full Text
- View/download PDF
98. New measurement of the 235U(nth,f) fission yields and development of a Time of Flight line at the LOHENGRIN spectrometer.
- Author
-
Houdouin-Quenault, M., Sage, C., Méplan, O., Ramdhane, M., Dauvergne, D., Gallin-Martel, M.L., Muraz, J.F., Guillaudin, O., Marcatili, S., Kessedjian, G., Chebboubi, A., Serot, O., Litaize, O., Bernard, D., Köster, U., Kim, Y.H., Mutti, P., and Smith, A.G.
- Subjects
NUCLEAR fission ,TIME-of-flight spectrometers ,NUCLEAR reactors ,ACTINIDE elements ,COVARIANCE matrices - Abstract
The study of nuclear fission yields has a major impact on the characterization and understanding of the fission process and is mandatory for reactor applications. In the framework of a collaboration between the CEA, the LPSC and the ILL, a program of actinide fission yield measurements has been ongoing for several years at the LOHENGRIN spectrometer. However, the measurement of very low fission yields in the symmetry region and the heavy wing of the distributions is difficult to achieve due to the strong contamination by other masses with much higher yields and requires the development of a new experimental setup. This paper will first present the results of a new absolute measurement of the
235 U(nth ,f) mass yields using an ionization chamber placed at the exit of the spectrometer. Although very well documented in the literature, these yields show uncertainties lying from 3% to 10% with large discrepancies between libraries and a lack of correlation matrices. New experimental data obtained at the LOHENGRIN spectrometer will be detailed, along with the measurement method and the production of the experimental covariance matrix. The second part will show the development of a Time of Flight (ToF) line in order to improve the background rejection in the mass yield measurements. In the symmetry region, the precision of the measurement is limited by the background estimation due to the charge exchanges with the residual gas of the separator. We plan to analyze the events using a triple coincidence (∆E x E) x ToF, whereas today only (∆E x E) selection is available. The new ToF line is built using Si3 N4 foils and secondary electron detectors (SED) for the start and stop detectors. We will present the choices made for the SED technology along with the progress achieved on the ToF line characterization. [ABSTRACT FROM AUTHOR]- Published
- 2023
- Full Text
- View/download PDF
99. The 41Ar(n,y)42Ar reaction.
- Author
-
Sahoo, R. N., Paul, M., Köster, U., Scott, R., Tessler, M., Zylstra, A., Avila, M. L., Dickerson, C., Jayatissa, H., Kohen, M.S., McLain, J., Pardo, R.C., Rehm, K. E., Tolstukhin, I., Vondrasek, R., Bailey, T., Callahan, L., Clark, A., Collon, P., and Kashiv, Y.
- Subjects
NUCLEAR cross sections ,THERMAL neutron capture ,ARGON isotopes ,NUCLEAR reactors ,MASS spectrometry - Abstract
The cross-section of the thermal neutron capture
41 Ar(n,γ)42 Ar(t1/2 =32.9 y) reaction was measured by irradiating a40 Ar sample at the high-flux reactor of Institut Laue-Langevin (ILL) Grenoble, France. The signature of the two-neutron capture has been observed by measuring the growth curve and identifying the 1524.6 keV γ-lines of the shorter-lived42 K(12.4 h) β− daughter of42 Ar. Our preliminary value of the41 Ar(n,γ)42 Ar thermal cross section is 240(80) mb at 25.3 meV. For the first time, direct counting of42 Ar was performed using the ultra-high sensitivity technique of noble gas accelerator mass spectrometry (NOGAMS) at Argonne National Laboratory, USA. [ABSTRACT FROM AUTHOR]- Published
- 2023
- Full Text
- View/download PDF
100. Testing the predictive power of realistic shell model calculations via lifetime measurement of the 11/2+ state in Sb131
- Author
-
Bottoni, S., primary, Gamba, E. R., additional, De Gregorio, G., additional, Gargano, A., additional, Leoni, S., additional, Fornal, B., additional, Brancadori, N., additional, Ciconali, G., additional, Crespi, F. C. L., additional, Cieplicka-Oryńczak, N., additional, Iskra, Ł. W., additional, Colombi, G., additional, Kim, Y. H., additional, Köster, U., additional, Michelagnoli, C., additional, Dunkel, F., additional, Esmaylzadeh, A., additional, Gerhard, L., additional, Jolie, J., additional, Knafla, L., additional, Ley, M., additional, Régis, J.-M., additional, Schomaker, K., additional, and Sferrazza, M., additional
- Published
- 2023
- Full Text
- View/download PDF
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