-
D. Hojman,
J. Sauvage,
B. Roussière,
M. A. Cardona,
G. Marguier,
A. Wojtasiewicz,
J. Genevey,
A. Gizon,
F. Ibrahim,
A. Knipper,
F. Le Blanc,
J. Obert, J. Oms,
the ISOLDE Collaboration
[show abstract]
[hide abstract]
ABSTRACT: Low-spin states of 182Ir were populated through the β+ /EC decay of 182Pt . Two strong E2 transitions were observed for the first time: a 25.7keV transition in 182Ir and a 34.0keV transition in Re of probable mass A = 178 . Spin and parity, I
π = 3+ , are firmly assigned to the 182Ir ground state (g.s.). For the excited states, the parity is established and the spin determined or restricted. These assignments
support most of the interpretations of the level structure previously suggested. The systematics for the known 5+ → 3+ transitions in π h
9/2 ⊗ ν 1/2-[521] bands is presented. Using a semi-microscopic two-quasiparticle axial-rotor coupling model, particle configurations have
been attributed or suggested for most of the coupled states lying at low energy in 182Ir .
European Physical Journal A 07/2007; 33(2):193-212. · 2.19 Impact Factor
-
D. Verney,
L. Cabaret,
J. E. Crawford,
H. T. Duong,
B. Fricke,
J. Genevey,
G. Huber,
F. Ibrahim,
M. Krieg,
F. Le Blanc, [......],
D. Lunney,
J. Obert, J. Oms,
J. Pinard,
J. C. Puteaux,
K. Rashid,
B. Roussière,
J. Sauvage,
V. Sebastian,
the ISOLDE Collaboration
[show abstract]
[hide abstract]
ABSTRACT: Laser spectroscopy measurements have been performed on neutron-deficient and stable Ir isotopes using the COMPLIS experimental
setup installed at ISOLDE-CERN. The radioactive Ir atoms were obtained from successive decays of a mass-separated Hg beam
deposited onto a carbon substrate after deceleration to 1kV and subsequently laser desorbed. A three-color, two-step resonant
scheme was used to selectively ionize the desorbed Ir atoms. The hyperfine structure (HFS) and isotope shift (IS) of the first
transition of the ionization path 5d
76s
24
F
9/2 → 5d
76s6p
6
F
11/2 at 351.5nm were measured for 182-189Ir, 186Ir
m
and the stable 191, 193Ir. The nuclear magnetic moments μI and the spectroscopic quadrupole moments Qs were obtained from the HFS spectra and the change of the mean square charge radii from the IS measurements. The sign of μI was experimentally determined for the first time for the masses 182≤A≤189 and the isomeric state 186Ir
m
. The spectroscopic quadrupole moments of 182Ir and 183Ir were measured also for the first time. A large mean square charge radius change between 187Ir and 186Ir
g
and between 186Ir
m
and 186Ir
g
was observed corresponding to a sudden increase in deformation: from β2 ≃ + 0.16 for the heavier group A = 193, 191, 189, 187 and 186m to β2≥ + 0.2 for the lighter group A = 186g, 185, 184, 183 and 182. These results were analyzed in the framework of a microscopic treatment of an axial rotor plus one
or two quasiparticle(s). This sudden deformation change is associated with a change in the proton state that describes the
odd-nuclei ground state or that participates in the coupling with the neutron in the odd-odd nuclei. This state is identified
with the π3/2+[402] orbital for the heavier group and with the π1/2-[541] orbital stemming from the 1h
9/2 spherical subshell for the lighter group. That last state seems to affect strongly the observed values of the nuclear moments.
European Physical Journal A 11/2006; 30(3):489-518. · 2.19 Impact Factor
-
F. Le Blanc,
L. Cabaret,
E. Cottereau,
J. E. Crawford,
S. Essabaa,
J. Genevey,
R. Horn,
G. Huber,
J. Lassen,
J. K. P. Lee,
G. Le Scornet,
J. Lettry,
J. Obert, J. Oms,
A. Ouchrif,
J. Pinard,
H. Ravn,
B. Roussière,
J. Sauvage,
D. Verney
[show abstract]
[hide abstract]
ABSTRACT: Laser spectroscopy measurements have been carried out on the neutron-rich tin isotopes with the COMPLIS experimental setup. Using the 5s25p2 3P0→5s25p6s 3P1 optical transition, hyperfine spectra of 126-132Sn and 125,127,129-131Snm were recorded for the first time. The nuclear moments and the mean square charge radius variation (δ〈rc2〉) were extracted. From the quadrupole moment values, these nuclei appear to be spherical. The magnetic moments measured are thus compared with those predicted by spherical basis approaches. From the measured δ〈rc2〉, the absolute charge radii of these isotopes were deduced in particular that of the doubly magic 132Sn nucleus. The comparison of the results with several mean-field-type calculations have shown that dynamical effects play an important role in the tin isotopes.
Phys. Rev. C. 09/2005; 72(3).
-
J. Sauvage,
F. Ibrahim,
B. Roussière,
J. Genevey,
A. Gizon,
G. Marguier,
P. Kilcher,
A. Knipper,
R. Béraud,
G. Căta-Danil,
F. Le Blanc,
J. Obert, J. Oms,
J. C. Putaux,
C. Richard-Serre,
A. Wojtasiewicz,
NICOLE Collaborations
[show abstract]
[hide abstract]
ABSTRACT: Low-spin states of 184Au have been studied using the β+/EC decay of 184Hg. γ-ray and conversion-electron singles spectra were recorded with 184Hg mass-separated sources. For γ-γ-t and X-γ-t coincidence measurements, mercury nuclei were produced in the 148Sm + 40Ar reaction and transported by a He-jet system. The electron spectra were recorded from 184Hg sources produced at ISOLDE. A level scheme of 184Au including 48 transitions is proposed. The experimental results are interpreted in the frame of a semi-microscopic axial-rotor-plus-two-quasiparticle model developed in the context of the HF+BCS approximation.
European Physical Journal A 06/2005; 25(1):5-21. · 2.19 Impact Factor
-
F. Le Blanc,
L. Cabaret,
J.E. Crawford,
S. Essabaa,
V. Fedoseyev,
W. Geithner,
J. Genevey,
M. Girod,
R. Horn,
G. Huber, [......],
J. Obert, J. Oms,
A. Ouchrif,
S. Peru,
J. Pinard,
H. Ravn,
B. Roussière,
J. Sauvage,
D. Verney,
and the Isolde Collaboration
[show abstract]
[hide abstract]
ABSTRACT: Laser spectroscopy measurements have been carried out on the very neutron-rich tin isotopes with the COMPLIS experimental
setup. Using the 5s
25p
23
P
0 → 5s
25p6s
3
P
1 optical transition, hyperfine spectra of 126-132Sn and 125m, 127m, 129m-131mSn where recorded for the first time. The variation of the mean-square charge radius ( δ〈r
2〉) between these nuclei and nuclear moments of the isomers and the odd isotopes were thus measured. An odd-even staggering
which inverts at A = 130 is clearly observed. This indicates a small appearance of a plateau on the δ〈r
2〉 which has to be confirmed by measuring the isotope shift beyond A = 132.
European Physical Journal A 01/2002; 15(1):49-51. · 2.19 Impact Factor
-
B. Roussière,
F. Ibrahim,
J. Libert,
J. Sauvage,
D. Verney,
L. Cabaret,
J. E. Crawford,
J. Genevey,
D. Hojman,
G. Huber,
A. Knipper,
F. Le Blanc,
J. K. P. Lee,
G. Marguier, J. Oms,
J. Pinard,
A. Wojtasiewicz
[show abstract]
[hide abstract]
ABSTRACT: We try to determine to what extent an “axial prolate rotor +1 or 2 quasiparticle model” succeeds in describing the transitional
odd and odd-odd Ir and Au nuclei. The relative location of the excited states, as well as the properties of the ground and
isomeric states, particularly the magnetic and spectroscopic quadrupole moments, is compared to the predictions of the model.
Physics of Atomic Nuclei 05/2001; 64(6):1048-1054. · 0.57 Impact Factor
-
J. Sauvage,
J. Libert,
B. Roussière,
D. Verney,
L. Cabaret,
J. E. Crawford,
J. Genevey,
G. Huber,
F. Ibrahim,
F. Le Blanc,
J. K. P. Lee, J. Oms,
J. Pinard
[show abstract]
[hide abstract]
ABSTRACT: Nuclear and atomic spectroscopy measurements have provided a great number of data on the neutron-deficient Pt and Hg nuclei.
The odd-A Pt and Hg with A<186 have a prolate shape, and the even-even isotopes have a triaxial shape, while the nuclear shape of the odd-A Pt and Hg with A>186 is still an open question. The energy of the low-lying levels and the nuclear moments have been calculated in the framework
of a semimicroscopic “axial-rotor + 1 quasiparticle” coupling model. The predictions are compared with the experimental data
and discussed. The results strongly suggest a prolate shape for the negative-parity low-lying states of the odd-A
187–191Pt and 187–193Hg isotopes.
Physics of Atomic Nuclei 01/2001; 64(6):1134-1140. · 0.57 Impact Factor
-
F. Ibrahim,
J. Genevey,
E. Cottereau,
A. Gizon,
A. Knipper,
F. Le Blanc,
G. Marguier,
J. Obert, J. Oms,
J.C. Putaux,
B. Roussière,
J. Sauvage,
A. Wojtasiewicz,
the ISOLDE Collaboration
[show abstract]
[hide abstract]
ABSTRACT: Low-lying states in the odd-odd light gold isotope 182Au have been populated by the β+/EC decay of the 182Hg nuclei. Level energies, spin and parity values were determined using on-line γ-ray and e- spectroscopy measurements. No isomeric state with a long half-life was found in the 182Au nucleus. Spin and parity I
π = 2+ can be very likely assigned to the 182Au ground state.
European Physical Journal A 01/2001; 10(2):139-143. · 2.19 Impact Factor
-
B. Roussière,
J. Genevey,
A. Gizon,
D. Hojman,
F. Ibrahim,
P. Kilcher,
A. Knipper,
F. Le Blanc,
G. Marguier,
J. Obert, J. Oms,
J.C. Putaux,
C. Richard-Serre,
J. Sauvage,
A. Wojtasiewicz,
D. Forkel-Wirth,
J. Lettry
[show abstract]
[hide abstract]
ABSTRACT: High-resolution measurements of low-energy conversion electrons have been performed in odd and odd–odd nuclei with masses
around A=182. The experimental setup, a magnetic spectrograph coupled to a specific tape transport system, is described. Three
experiments have been performed and the main results are presented.
Hyperfine Interactions 11/2000; 129(1):119-129. · 0.21 Impact Factor
-
J. Sauvage,
N. Boos,
L. Cabaret,
J.E. Crawford,
H.T. Duong,
J. Genevey,
M. Girod,
G. Huber,
F. Ibrahim,
M. Krieg, [......],
D. Verney,
S. Zemlyanoi,
J. Arianer,
N. Barré,
M. Ducourtieux,
D. Forkel-Wirth,
G. Le Scornet,
J. Lettry,
C. Richard-Serre,
C. Véron
[show abstract]
[hide abstract]
ABSTRACT: Laser spectroscopy measurements have been carried out on very neutron-deficient isotopes of Au, Pt and Ir, produced as daughter
elements from a Hg ISOLDE beam. For these transitional region nuclides, the hyperfine structure (HFS) and isotope shift (IS)
were measured by Resonance Ionization Spectroscopy (RIS). Magnetic moments μ, spectroscopic quadrupole moments Qs and changes of the nuclear mean square charge radius δ〈rc
2〉along isotopic series have been extracted. For some results, a detailed comparison with theoretical predictions is presented.
Hyperfine Interactions 11/2000; 129(1):303-317. · 0.21 Impact Factor
-
D. Verney,
F. Le Blanc,
L. Cabaret,
J. Crawford,
H.T. Duong,
J. Genevey,
G. Huber,
F. Ibrahim,
M. Krieg,
J.K.P. Lee,
D. Lunney,
J. Obert, J. Oms,
J. Pinard,
J.C. Putaux,
B. Roussière,
J. Sauvage,
V. Sebastian
[show abstract]
[hide abstract]
ABSTRACT: Laser spectroscopy measurements have been performed on neutron deficient iridium isotopes. The hyperfine structure and isotope
shift of the optical Ir I transition 5d76s2
4F9/2 → 5d76s6p 6F11/2 at 351.5 nm have been studied for the 182–189Ir,
186 \textIr\user1m ^{186} {\text{Ir}}^\user1{m}
and 191,193Ir isotopes. The nuclear magnetic and quadrupole moments were obtained from the HFS measurements and the changes of the mean
square charge radii from the IS measurements. A large mean square charge radius change between 187Ir and 186Ir and between
186 \textIr\user1m ^{186} {\text{Ir}}^\user1{m}
and
186 \textIr\user1g ^{186} {\text{Ir}}^\user1{g}
has been observed.
Hyperfine Interactions 07/2000; 127(1):79-82. · 0.21 Impact Factor
-
J. Sauvage,
L. Cabaret,
J. Crawford,
H. T. Duong,
J. Genevey,
M. Girod,
A. Gizon,
D. Hojman,
G. Huber,
F. Ibrahim, [......],
J. Obert, J. Oms,
J. Pinard,
J. C. Putaux,
B. Roussiere,
V. Sebastian,
A. Wojtasiewicz,
S. Zemlyanoi,
D. Forkel-Wirth,
J. Lettry
[show abstract]
[hide abstract]
ABSTRACT: Atomic spectroscopy measurements were carried out using the COMPLIS
setup installed at the ISOLDE-BOOSTER facility. Hyperfine structure
(HFS) spectra and isotope shift (IS) values were obtained for the
neutron-deficient 178-185Pt and for
184Aug,m, providing deformation parameters β
, magnetic moments μ and spectroscopic quadrupole moments (for I ≥
1) Qs . In Pt isotopes, a deformation drop for A=178 and an
inverted odd-even staggering for the charge radius around the neutron
mid-shell N=104, have been observed very clearly. Furthermore,
deformation changes δ β between isomeric and ground states
for 183,185Pt and 184Au have been put forward.
Thus, the influence of the proton-neutron coupling on the δ β
value in 184Au relatively to that in its isotone
183Pt has been determined. Besides, the h9/2
proton state that is decoupled from the core in 183,185Au,
becomes the 3/2 [532] state strongly coupled in 184Au. The
spin and parity values Iπ =3+ have been
assigned to the 182Ir ground state from internal conversion
electron measurements to prepare atomic spectroscopy studies in the Ir
isotopic series.
Acta Physica Polonica Series B 04/1999; 30:1393. · 0.90 Impact Factor
-
[show abstract]
[hide abstract]
ABSTRACT: The decay of181Ir has been studied on-line with mass-separated sources from the ISOCELE facility. The level scheme of181 Os has been established. The isomeric state has been located at 48.9 keV above the ground state. Thus the isomeric and ground states are identified as the 7/2–(T1/2 =2.7 m) and 1/2–(T1/2=105 m) levels respectively.
Zeitschrift für Physik A Hadrons and Nuclei 05/1995; 351(2):127-128.
-
B. Roussière,
E. Le Blanc,
G. Savard,
H. T. Duong,
J. Pinard,
S. Liberman,
J. K. P. Lee,
J. E. Crawford,
G. Thekkadath,
P. Kilcher,
J. Obert, J. Oms,
J. C. Putaux,
J. Sauvage,
ISOCELE Collaboration
[show abstract]
[hide abstract]
ABSTRACT: Isotope shift (IS) and hyperfine structure (HFS) measurements have been performed for185, 187, 189, 191, 195Pt using the PILIS (Post ISOCELE Laser Isobar Separator) apparatus installed at the ISOCELE facility. Magnetic and quadrupole
moments have been deduced from the HFS results. The charge radius changes determined for these odd nuclei from the IS results,
added to the σ values of the even-A nuclei are compared to the results of lattice Hartree-Fock+BCS calculations for asymmetric solutions:185Pt is confirmed to be prolate shaped whereas187, 189, 191Pt are likely triaxial in their ground states.
Hyperfine Interactions 01/1988; 43(1):473-476. · 0.21 Impact Factor
-
R. Sifi,
F. Le Blanc,
N. Barré,
L. Cabaret,
J. Crawford,
M. Ducourtieux,
S. Essabaa,
J. Genevey,
G. Huber,
M. Kowalska,
C. Lau,
J. K. P. Lee,
G. Le Scornet, J. Oms,
J. Pinard,
B. Roussière,
J. Sauvage,
M. Seliverstov,
H. Stroke,
ISOLDE
[show abstract]
[hide abstract]
ABSTRACT: Laser spectroscopy based on resonant ionization of laser-desorbed atoms has been used to study the neutron-rich tellurium
isotopes with the COMPLIS facility at ISOLDE-CERN. Isotope shifts and hyperfine structures of several neutron-rich Te isotopes:
120–136Te and 123 m–133 mTe have been measured. From the hyperfine structure we have extracted magnetic and quadrupole moments. Changes in the mean
square charge radii have been deduced and their comparison with the known data for the other elements near Z=50 is presented. The experimental δ<r
2> values are compared with those obtained from relativistic mean field calculations.
Key wordslaser spectroscopy-isotope shift-hyperfine structure-nuclear moments
01/1970: pages 173-179;
-
L A Cabaret,
J Crawford,
V. N. Fedoseyev,
W Geithner,
J. Genevey,
M. Girod,
G. Hubert,
S Kappertz,
J Lassen,
F. Le Blanc, [......], J. Oms,
S. Peru,
J Pinard,
H L Ravn,
B. Roussiere,
J. Sauvage,
D. Verney,
S. Essabaa,
R. Horn,
A. Ouchrift
-
B. Roussiere,
L. Cabaret,
J E Crawford,
S. Essabaa,
V. Fedoseyev,
W Geithner,
J. Genevey,
M. Girod,
G Huber,
R. Horn, [......],
V. Mishin,
R Neugart,
J. Obert, J. Oms,
A. Ouchrif,
S. Peru,
J Pinard,
H L Ravn,
J. Sauvage,
D. Verney
-
D. Hojman,
J. Sauvage,
B. Roussière,
M.A. Cardona,
G Marguier,
A. Wojtasiewicz,
J. Genevey,
A Gizon,
F. Ibrahim,
A Knipper,
F. Le Blanc,
J. Obert, J. Oms
[show abstract]
[hide abstract]
ABSTRACT: Low-spin states of $^{182}Ir$ were populated through the $\beta^+/EC$ decay of $^{182}Pt$. Two strong $E2$ transitions were observed for the first time: a 25.7keV transition in $^{182}Ir$ and a 34.0keV transition in Re of probable mass A = 178. Spin and parity, $I^\pi = 3^+$, are firmly assigned to the $^{182}Ir$ ground state (g.s.). For the excited states, the parity is established and the spin determined or restricted. These assignments support most of the interpretations of the level structure previously suggested. The systematics for the known $5^+ \to 3^+$ transitions in $\pi h_{9/2} \bigotimes ν 1/2^-[521]$ bands is presented. Using a semi-microscopic two-quasiparticle axial-rotor coupling model, particle configurations have been attributed or suggested for most of the coupled states lying at low energy in $^{182}Ir$.
-
H.T. Duong,
J. Pinard,
S. Liberman,
G. Savard,
J.K.P. Lee,
J.E. Crawford,
G. Thekkadath,
F. Le Blanc,
P. Kilcher,
J. Obert, J. Oms,
J.C. Putaux,
B. Roussière,
J. Sauvage
[show abstract]
[hide abstract]
ABSTRACT: Isotope shift (IS) and hyperfine structure (HFS) measurements have been performed for 185,187,189,191,195Pt using the PILIS (Post ISOCELE Laser Isobar Separation) apparatus installed at the ISOCELE facility. Magnetic and quadrupole moments have been deduced from the HFS results. The change radius changes determined for these odd nuclei from the IS results, added to the δ values of the even-A nuclei, are compared to the results of lattice Hartee-Fock+BCS calculations for asymmetric solutions. 185Pt is confirmed to be prolate shaped whereas 187,189,191Pt are likely triaxial in their ground states.
Physics Letters B.
-
B. Roussière,
P. Kilcher,
A. Wojtasiewicz,
J. Genevey,
A. Gizon,
F. Ibrahim,
A. Knipper,
F. Le Blanc,
G. Marguier,
J. Obert, J. Oms,
J.C. Putaux,
M. Ramdhane,
J. Sauvage
[show abstract]
[hide abstract]
ABSTRACT: The M3 transitions linking the and states in 78183Pt105 and 76181Os105 have been searched by high-resolution conversion-electron measurements. The reduced M3 transition probabilities have been estimated and compared to the values obtained in neighbouring isotones (74179W105 and 79184Au105). All the known M3 transitions are presented and their properties discussed, especially as a function of deformation. The present work supports the and particle configuration assignments proposed for the 184Au isomeric and ground states, respectively.
Nuclear Physics A.
