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D. R. Atanasov,
N. Winckler,
D. Balabanski,
L. Batist,
F. Bosch,
D. Boutin,
C. Brandau, C. Dimopoulou,
H. G. Essel,
T. Faestermann, [......],
M. Steck,
Th. Stöohlker,
B. Sun,
T. Suzuki,
M. Trassinelli,
I. I. Tupitsyn,
H. Weick,
M. Winkler,
D. F. A. Winters,
T. Yamaguchi
European Physical Journal A 01/2012; 48:22. · 2.19 Impact Factor
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M W Reed,
P M Walker,
I J Cullen,
Yu. A Litvinov,
D Shubina,
G D Dracoulis,
K Blaum,
F Bosch,
C Brandau,
J J Carroll, [......],
Th. Stoehlker,
B Sun,
T P D Swan,
G Trees,
H Weick,
N Winckler,
M Winkler,
P J Woods,
F R Xu,
T Yamaguchi
[show abstract]
[hide abstract]
ABSTRACT: A study of neutron-rich isotopes in the A = 185 region of the nuclear chart has uncovered long-lived (>1 s) isomers in several isotopes of hafnium, tantalum, tungsten, rhenium, and osmium. The region was accessed via the use of projectile fragmentation with the UNILAC-SIS accelerators at GSI. Fragmentation products of Au-197 were passed through the fragment separator (FRS) and injected into the experimental storage ring (ESR), where single-ion identifications could be made. Evidence is presented for isomers in Hf-183,Hf-184,Hf-186, Ta-186,Ta-187, W-186, Re-190,Re-192,Re-194, and Os-195 with excitation energies in the range of 0.1-3.0 MeV. The lightest of these nuclides have well deformed prolate shapes, while the heaviest are transitional and susceptible to shape changes. Their properties are interpreted with the help of multi-quasiparticle and potential-energy-surface calculations.
Physical Review C 01/2012; 86(5). · 3.31 Impact Factor
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M W Reed,
P M Walker,
I J Cullen,
Yu A Litvinov,
K Blaum,
F Bosch,
C Brandau,
J J Carroll,
D M Cullen,
A Y Deo, [......],
M Steck,
Th Stoehlker,
B Sun,
T P D Swan,
G Trees,
H Weick,
N Winckler,
M Winkler,
P J Woods,
T Yamaguchi
[show abstract]
[hide abstract]
ABSTRACT: A recent experiment using projectile fragmentation of a Au-197 beam on a Be-9 target, combined with the fragment recoil separator and experimental storage ring at ring at GSI, has uncovered an isomeric state in Re-192 at 267(10) keV with a half-life of similar to 60 s. The data analysis technique used to resolve the isomeric state from the ground state is discussed.
RUTHERFORD CENTENNIAL CONFERENCE ON NUCLEAR PHYSICS; 01/2012
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B Sun,
F. Bosch,
D. Boutin,
C. Brandau,
L Chen, C. Dimopoulou,
B. Fabian,
H. Geissel,
R. Knöbel,
C. Kozhuharov, [......],
G. Münzenberg,
C. Nociforo,
F. Nolden,
W. R. Plaß,
C. Scheidenberger,
M. Steck,
P. M. Walker,
H. Weick,
Nicolas Winckler,
M Winkler
Nuclear Physics A 12/2010; 834(1):476c-478c. · 1.54 Impact Factor
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M W Reed,
I J Cullen,
P M Walker,
Yu A Litvinov,
K Blaum,
F Bosch,
C Brandau,
J J Carroll,
D M Cullen,
A Y Deo, [......],
M Steck,
Th Stöhlker,
B Sun,
T P D Swan,
G Trees,
H Weick,
N Winckler,
M Winkler,
P J Woods,
T Yamaguchi
[show abstract]
[hide abstract]
ABSTRACT: A study of cooled ¹⁹⁷Au projectile-fragmentation products has been performed with a storage ring. This has enabled metastable nuclear excitations with energies up to 3 MeV, and half-lives extending to minutes or longer, to be identified in the neutron-rich nuclides ¹⁸³(,)¹⁸⁴(,)¹⁸⁶Hf and ¹⁸⁶(,)¹⁸⁷Ta. The results support the prediction of a strongly favored isomer region near neutron number 116.
Physical Review Letters 10/2010; 105(17):172501. · 7.37 Impact Factor
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J. Kurcewicz,
F. Bosch,
H. Geissel,
Yuri A. Litvinov,
Nicolas Winckler,
K. Beckert,
P. Beller,
D. Boutin,
L Chen, C. Dimopoulou, [......],
R. Reuschl,
C. Scheidenberger,
M. Steck,
Thomas Stöhlker,
B Sun,
K Takahashi,
S. Torilov,
M. Trassinelli,
H. Weick,
M Winkler
Acta Physica Polonica B, v.41, 525-536 (2010). 03/2010; 41:525-536.
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N. Winckler,
H. Geissel,
Yu.A. Litvinov,
K. Beckert,
F. Bosch,
D. Boutin,
C. Brandau,
L. Chen, C. Dimopoulou,
H.G. Essel, [......],
R. Reda,
R. Reuschl,
C. Scheidenberger,
M. Steck,
T. Stöhlker,
S.Yu. Torilov,
M. Trassinelli,
B. Sun,
H. Weick,
M. Winkler
[show abstract]
[hide abstract]
ABSTRACT: The β+ and orbital electron-capture decays of stored hydrogen- and helium-like 142Pm ions have been measured. So far, such measurements have been performed with only one nucleus, namely 140Pr. The electron-capture decay constant of hydrogen-like 142Pm60+ ions is about 50% larger than that of helium-like 142Pm59+ ions, which is in excellent agreement with the previous measurements in 140Pr ions and with new theoretical predictions.
Physics Letters B 07/2009; 679:36-40. · 3.95 Impact Factor
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B Sun,
R K Obel,
Yu A Litvinov,
S Nakajima,
H Geissel,
J Meng,
K Beckert,
F Bosch,
D Boutin,
C Brandau, [......],
C Scheidenberger,
M Steck,
T Suzuki,
P M Walker,
H Weick,
N Winckler,
M Winkler,
T Yamaguchi,
B Sun@gsi,
De
[show abstract]
[hide abstract]
ABSTRACT: Precise mass measurements of short-lived exotic nuclei are very important for the under-standing of basic nuclear structure physics and astrophysical nucleosynthesis in nature, as well as for the test and the development of theoretical nuclear mass models. At GSI, the Isochronous Mass Spectrometry (IMS) dedicated to mass measurements of short-lived nuclides was developed. In this contribution, the IMS technique is briefly reviewed. Recently, the first large-scale measurement on the 238 U fission fragment was done suc-cessfully. The measured mass values are in excellent agreement with the recent Penning trap data, however, they show a systematical deviation from the values in the latest atomic mass evaluation. Some representative results from this experiment will be pre-sented, including their impact on nuclear structure physics and astrophysical r-process nucleosynthesis.
International Journal of Modern Physics E 01/2009; 18(1):346-351. · 0.60 Impact Factor
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M. Steck,
U. Blell, C. Dimopoulou,
A. Dolinskii,
P. Forck,
B. Franzke,
O. Gorda,
V. Gostishchev,
U. Jandewerth,
T. Katayama, [......],
P. Petri,
H. Ramakers,
I. Schurig,
M. Schwickert,
H. Welker,
R. Bär,
A. Krämer,
C. Mühle,
L. Thorndahl,
D. Möhl
[show abstract]
[hide abstract]
ABSTRACT: The preparation of high quality secondary beams in the new FAIR facility is founded in a system of three storage rings equipped with various beam cooling systems. Depending on the beam species, which can be either rare isotope beams or antiprotons, the storage rings have different tasks such as pre-cooling, accumulation or deceleration of secondary beams. Operation with stable highly charged ions is another mode of the storage rings. The ion optical design has been refined in order to have optimum performance
for the planned applications. Beam cooling systems for the storage rings were specified in detail and a hardware development program has been launched. In parallel, the civil engineering design and the design of the technical infrastructure for the FAIR project is progressing.
PAC09, Vancouver, BC, Canada; 01/2009
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A Musumarra,
F Farinon,
C Nociforo,
H Geissel,
G Baur,
K -H Behr,
A Bonasera,
F Bosch,
D Boutin,
A Brunle, [......],
P Strmen,
B Sun,
T Suzuki,
I Szarka,
D Torresi,
H Weick,
J S Winfield,
M Winkler,
H J Wollersheim,
T Yamaguchi
Proc.Intern.Conf.on Nuclear Structure and Dynamics; 01/2009
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B. Sun,
R. Knöbel,
Yu.A. Litvinov,
H. Geissel,
J. Meng,
K. Beckert,
F. Bosch,
D. Boutin,
C. Brandau,
L. Chen, [......],
Z. Patyk,
W.R. Plaß,
C. Scheidenberger,
M. Steck,
T. Suzuki,
P.M. Walker,
H. Weick,
N. Winckler,
M. Winkler,
T. Yamaguchi
[show abstract]
[hide abstract]
ABSTRACT: The previously pioneered Isochronous Mass Spectrometry (IMS) has been extended by an additional precise magnetic-rigidity determination to enable accurate large-scale measurements of stored short-lived relativistic nuclei with the FRS-ESR facility at 382 MeV/u. With this novel experimental tool the mass resolving power and accuracy have been improved by a factor of about 3. The recorded broad-band revolution time spectrum corresponds to the mass-over-charge range of about 6%. A mass resolving power of 200 000 (FWHM) and a typical accuracy of 120 keV have been achieved almost over the entire spectrum. The masses of 35 neutron-rich nuclides have been directly measured in the element range from aluminum to barium. The Masses of 8 nuclides (85,86As, 89Se, 123Ag, 138Te, 140,141I, 143Xe) have been measured for the first time. The results are compared with previous experimental data and theoretical predictions. The evolution of the N=50 shell closure towards doubly-magic 78Ni is discussed.
Nuclear Physics A 11/2008; 812(1):1-12. · 1.54 Impact Factor
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Yu. A. Litvinov,
F. Bosch,
N. Winckler,
D. Boutin,
H. G. Essel,
T. Faestermann,
H. Geissel,
S. Hess,
P. Kienle,
R. Knöbel, [......],
R. Reda,
R. Reuschl,
C. Scheidenberger,
M. Steck,
T. Stöhlker,
S. Torilov,
M. Trassinelli,
B Sun,
H. Weick,
M Winkler
[show abstract]
[hide abstract]
ABSTRACT: It is argued that orbital electron-capture decays of neutral $^{142}$Pm atoms implanted into the lattice of a solid (LBNL experiment) do not fulfil the constraints of true two-body beta decays, since momentum as well as energy of the final state are distributed among three objects, namely the electron neutrino, the recoiling daughter atom and the lattice phonons. To our understanding, this could be a reason for the non-observation of a periodic time modulation in the number of electron-capture decays of implanted neutral $^{142}$Pm atoms.
08/2008;
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Yu.A. Litvinov,
F. Bosch,
N. Winckler,
D. Boutin,
H.G. Essel,
T. Faestermann,
H. Geissel,
S. Hess,
P. Kienle,
R. Knöbel, [......],
R. Reda,
R. Reuschl,
C. Scheidenberger,
M. Steck,
T. Stöhlker,
S. Torilov,
M. Trassinelli,
B. Sun,
H. Weick,
M. Winkler
[show abstract]
[hide abstract]
ABSTRACT: We report on time-modulated two-body weak decays observed in the orbital electron capture of hydrogen-like 140Pr59+ and 142Pm60+ ions coasting in an ion storage ring. Using non-destructive single ion, time-resolved Schottky mass spectrometry we found that the expected exponential decay is modulated in time with a modulation period of about 7 seconds for both systems. Tentatively this observation is attributed to the coherent superposition of finite mass eigenstates of the electron neutrinos from the weak decay into a two-body final state.
Physics Letters B. 03/2008; 664:162-168.
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Yu. A. Litvinov,
F. Bosch,
N. Winckler,
D. Boutin,
H. G. Essel,
T. Faestermann,
H. Geissel,
S. Hess,
P. Kienle,
R. Knöbel, [......],
R. Reda,
R. Reuschl,
C. Scheidenberger,
M. Steck,
T. Stöhlker,
S. Torilov,
M. Trassinelli,
B Sun,
H. Weick,
M Winkler
[show abstract]
[hide abstract]
ABSTRACT: We report on time-modulated two-body weak decays observed in the orbital electron capture of hydrogen-like $^{140}$Pr$^{59+}$ and $^{142}$Pm$^{60+}$ ions coasting in an ion storage ring. Using non-destructive single ion, time-resolved Schottky mass spectrometry we found that the expected exponential decay is modulated in time with a modulation period of about 7 seconds for both systems. Tentatively this observation is attributed to the coherent superposition of finite mass eigenstates of the electron neutrinos from the weak decay into a two-body final state. Comment: 12 pages, 5 figures
01/2008;
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J Kurcewicz,
Yu. A Litvinov,
F Bosch,
H Geissel,
Z Patyk,
N Winckler,
L Batist,
K Beckert,
P Beller,
D Boutin, [......],
A Musumarra,
C Nociforo,
F Nolden,
M Pfutzner,
W Plass,
C Scheidenberger,
M Steck,
B Sun,
H Weick,
M Winkler
Acta Physica Polonica Series B 01/2008; B39:501. · 0.90 Impact Factor
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Yu. A. Litvinov,
F. Bosch,
H. Geissel,
J. Kurcewicz,
Z. Patyk,
N. Winckler,
L. Batist,
K. Beckert,
D. Boutin,
C. Brandau, [......],
R. Reda,
R. Reuschl,
C. Scheidenberger,
M. Steck,
T. Stöhlker,
S. Torilov,
M. Trassinelli,
B Sun,
H. Weick,
M Winkler
[show abstract]
[hide abstract]
ABSTRACT: We report on the first measurement of the $\beta^+$- and orbital electron capture decay rates of $^{140}$Pr nuclei with the most simple electron configurations: bare nuclei, hydrogen-like and helium-like ions. The measured electron capture decay constant of hydrogen-like $^{140}$Pr$^{58+}$ ions is about 50% larger than that of helium-like $^{140}$Pr$^{57+}$ ions. Moreover, $^{140}$Pr ions with one bound electron decay faster than neutral $^{140}$Pr$^{0+}$ atoms with 59 electrons. To explain this peculiar observation one has to take into account the conservation of the total angular momentum, since only particular spin orientations of the nucleus and of the captured electron can contribute to the allowed decay.
Physical Review Letters 12/2007; · 7.37 Impact Factor
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[show abstract]
[hide abstract]
ABSTRACT: Production of rare isotope beams is one of the most important tasks of the accelerators of the FAIR project. The rare isotope beams can be stored in the NESR storage ring where powerful electron allows high precision experiments. Various modes for experiments are foreseen, interaction with internal targets, collisions with counter- propagating electrons or antiprotons, deceleration of the ions from the injection energy of 740 MeV/u to a minimum energy of 4 MeV/u and mass measurements by Schottky noise detection. If the intensity of single shots of rare isotopes is too low, a longitudinal accumulation scheme in combination with electron cooling allows accumulation of intense rare isotope beams.
Particle Accelerator Conference, 2007. PAC. IEEE; 07/2007
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Yu.A. Litvinov,
H. Geissel,
K. Beckert,
P. Beller,
F. Bosch,
D. Boutin,
C. Brandau,
L. Chen,
I. Cullen, C. Dimopoulou, [......],
W. Plass,
C. Scheidenberger,
M. Steck,
B. Sun,
T. Suzuki,
P.M. Walker,
H. Weick,
N. Winckler,
M. Winkler,
T. Yamaguchi
[show abstract]
[hide abstract]
ABSTRACT: Schottky Mass Spectrometry (SMS) and Isochronous Mass Spectrometry (IMS) have been successfully applied for direct mass measurements of exotic nuclides at FRS-ESR facility at GSI. Both experimental methods are sensitive to single stored ions and can cover very efficiently a large number of nuclides in one run. Presently, more than 1100 masses of different nuclides have been covered by SMS and IMS in several FRS-ESR experiments whereby about 350 of them have been determined for the first time. In this paper, we present the status of our experimental program and use the experimental mass values to test the predictive power of modern mass models.
Nuclear Physics A 03/2007; 787:315-320. · 1.54 Impact Factor
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B. Sun,
Yu. A. Litvinov,
P. M. Walker,
K. Beckert,
P. Beller,
F. Bosch,
D. Boutin,
C. Brandau,
L. Chen, C. Dimopoulou, [......],
S. A. Litvinov,
M. Mazzocco,
J. Meng,
C. Nociforo,
F. Nolden,
W. R. Plass,
C. Scheidenberger,
M. Steck,
H. Weick,
M. Winkler
[show abstract]
[hide abstract]
ABSTRACT: A new long-lived isomeric state in the near proton dripline nucleus 125Ce has been identified with Schottky mass spectrometry at GSI. The excitation energy E
* = 103(12)keV and the decay time of 193(1)s have been obtained from a single stored fully ionized 125m
Ce58+ ion. The data implies an E3 transition and a 1/2+ assignment for the spin of the isomer.
European Physical Journal A 02/2007; 31(3):393-394. · 2.19 Impact Factor
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Yu A Litvinov,
F Bosch,
H Geissel,
J Kurcewicz,
Z Patyk,
N Winckler,
L Batist,
K Beckert,
D Boutin,
C Brandau, [......],
R Reda,
R Reuschl,
C Scheidenberger,
M Steck,
T Stöhlker,
S Torilov,
M Trassinelli,
B Sun,
H Weick,
M Winkler
[show abstract]
[hide abstract]
ABSTRACT: We report on the first measurement of the beta+ and orbital electron-capture decay rates of 140Pr nuclei with the simplest electron configurations: bare nuclei, hydrogenlike, and heliumlike ions. The measured electron-capture decay constant of hydrogenlike 140Pr58+ ions is about 50% larger than that of heliumlike 140Pr57+ ions. Moreover, 140Pr ions with one bound electron decay faster than neutral 140Pr0+ atoms with 59 electrons. To explain this peculiar observation one has to take into account the conservation of the total angular momentum, since only particular spin orientations of the nucleus and of the captured electron can contribute to the allowed decay.
Physical Review Letters 01/2007; 99(26):262501. · 7.37 Impact Factor
