共查询到20条相似文献,搜索用时 46 毫秒
1.
N. Hashimoto T.R. Saitoh G. Sletten R.A. Bark M. Bergström K. Furuno T. Komatsubara T. Shizuma S. Törmänen P.G. Varmette 《The European Physical Journal A - Hadrons and Nuclei》1998,2(4):327-330
Abstact: High-spin states in 183Re have been studied using the 176Yb(11B,4n) reaction at 52 and 57 MeV. Two high-K bands have been observed directly by a time-correlated γ-γ coincidence measurement. One of the bands is built on an isomeric
K
π=(25/2)+ state at E
x= 1908 keV with a half-life of 0.82(2) ms. The other band, assigned as K
π=(29/2)− at E
x= 2739 keV, decays to the (25/2)+ band. These bands are interpreted as three-quasiparticle structures, π(5/2)+[402] &⊗ν(9/2)+[624] ⊗ν(11/2)+[615] for the (25/2)+ band and π(9/2)−[514] ⊗ν(9/2)+[624] ⊗ν(11/2)+[615] for the (29/2)− band. The K
π= (29/2)− band becomes strongly Coriolis mixed with increasing spin and is gradually changing into a low-K s-band structure.
Received: 20 April 1998 相似文献
2.
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 European Physical Journal A - Hadrons and Nuclei》2001,10(2):139-143
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.
Received: 19 December 2000 / Accepted: 28 February 2001 相似文献
3.
J. Khuyagbaatar S. Hofmann F. P. Heßberger D. Ackermann S. Antalic H. G. Burkhard S. Heinz B. Kindler A. F. Lisetskiy B. Lommel R. Mann K. Nishio H. J. Schött B. Sulignano 《The European Physical Journal A - Hadrons and Nuclei》2007,34(4):355-361
Isomeric states in 214Th and 213Th were identified by means of γ -rays measured in delayed coincidence with the implanted evaporation residues. These were
produced in irradiations of 164Dy with 54Cr projectiles and separated in-flight by the velocity filter SHIP. An isomeric state of I
π = 8+ with a half-life of (1.24±0.12) μs was identified in 214Th . The configuration π[1h
9/2 ⊗ 2f
7/2] was assigned to this state. An isomeric state with a half-life of (1.4±0.4) μs was observed in 213Th . Tentatively it was assigned to an I
π = 13/2+ state. 相似文献
4.
Yu.N. Novikov H. Schatz P. Dendooven R. Béraud Ch. Miehé A.V. Popov D.M. Seliverstov G.K. Vorobjev P. Baumann M.J.G. Borge G. Canchel Ph. Desagne A. Emsallem W. Huang J. Huikari A. Jokinen A. Knipper V. Kolhinen A. Nieminen M. Oinonen H. Penttilä K. Peräjärvi I. Piqueras S. Rinta-Antila J. Szerypo Y. Wang J. Äystö 《The European Physical Journal A - Hadrons and Nuclei》2001,11(3):257-261
A careful investigation of the isomeric transition of the long-lived state at 228.5 keV excitation energy in 80Y has been done. The HIGISOL facility at the Jyv?skyl? isochronous cyclotron has been used. We used the electron magnetic
transporter to prepare an appropriate source and to measure the electron spectra in clean background conditions. The measured
internal conversion coefficient αK = 0.50±0.07 allows unambiguous 1- identification for the 228.5 keV first excited isomeric state in 80Y. With a “bare" half-life of 6.8±0.5 s found in this work, this state is strongly populated in the rp-process during X-ray
bursts and has therefore to be taken into account in X-ray burst model calculations. However, because of the similarity of
the β-decay half-lives of isomeric and ground states, we find a maximum reduction in the effective β-decay lifetime of 80Y of only 17±2%. Our results pave the way for a future investigation of the impact of the isomeric state on the “effective"
80Y proton capture rate.
Received: 14 March 2001 / Accepted: 10 July 2001 相似文献
5.
J. Ekman D. Rudolph C. Fahlander R.J. Charity W. Reviol D.G. Sarantites V. Tomov R.M. Clark M. Cromaz P. Fallon A.O. Macchiavelli M. Carpenter D. Seweryniak 《The European Physical Journal A - Hadrons and Nuclei》2000,9(1):13-17
Eighteen previously unknown γ-ray transitions were identified in the T
z = - 1/2 nucleus 51Fe following the fusion-evaporation reaction 32S(28Si,2α1n)51Fe. The level scheme reaches the fully aligned I
π = 27/2- terminating state of the five holes in the f
7/2 shell. The 17/2- state was found to be isomeric, and the lifetime was measured to be 2.87 ns. The mirror symmetry of 51Fe and 51Mn is discussed, and the level scheme of 51Fe is compared to shell-model calculations.
Received: 20 July 2000 / Accepted: 1 August 2000 相似文献
6.
C. Foin A. Gizon J. Genevey J. Gizon P. Paris F. Farget D. Santos D. Barnéoud A. Płochocki 《The European Physical Journal A - Hadrons and Nuclei》2002,14(1):7-11
A high-spin level structure of the nucleus 154Tm has been established for the first time up to 6.14 MeV. The 118Sn + 40Ca reaction at 205 MeV associated with the recoil shadow method was used to identify the I
π = (19)+ isomeric state at 2.74 MeV. In-beam γ-ray and conversion electron spectroscopy have been applied on the 144Sm(14N, 4n)154Tm reaction at 95 MeV to build the level scheme. The level structure of 154Tm is compared to other structures observed in N = 85 neighbouring nuclei.
Received: 4 January 2002 / Accepted: 15 March 2002 相似文献
7.
Vinod Kumar Pragya Das R.P. Singh S. Muralithar R.K. Bhowmik 《The European Physical Journal A - Hadrons and Nuclei》2003,17(2):153-157
The fusion evaporation reaction 122Sn(14N, 4n)132La was used to populate the high-spin states of 132La at the beam energy of 60 MeV. A new band consisting of mostly E2 transitions has been discovered. This band has the interesting links to the ground state 2- and the isomeric state 6-. A new transition of energy 351 keV connecting the low-spin states of the positive-parity band based on the πh
11/2 ⊗ νh
11/2 particle configuration, has been found. This has played a very important role in resolving the existing ambiguities and inconsistencies
in the spin assignment of the band head.
Received: 12 August 2002 / Accepted: 18 March 2003 / Published online: 7 May 2003 相似文献
8.
B. Sun Yu. A. Litvinov P. M. Walker K. Beckert P. Beller F. Bosch D. Boutin C. Brandau L. Chen C. Dimopoulou H. Geissel R. Knöbel C. Kozhuharov J. Kurcewicz S. A. Litvinov M. Mazzocco J. Meng C. Nociforo F. Nolden W. R. Plass C. Scheidenberger M. Steck H. Weick M. Winkler 《The European Physical Journal A - Hadrons and Nuclei》2007,31(3):393-394
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. 相似文献
9.
A. Gizon J. Genevey C.F. Liang P. Paris D. Barnéoud J. Inchaouh I. Penev A. Plochocki 《The European Physical Journal A - Hadrons and Nuclei》2001,12(3):309-316
An investigation of low-lying energy levels of 130Pr and 130Ce has been made via β-decay. The radioactive parent nuclei were produced via 94,96Mo + 40Ca reactions at 6.8 MeV/nucleon and transported by a He-jet system. Gamma-γ-t, γ-X-t, γ-e--t coincidence measurements were performed. Internal conversion coefficients have been measured with a magnetic spectrometer.
The new β-decay half-life of 130Nd has been determined to be 21(3) s. A partial level scheme of 130Pr at low-spin has been constructed. The β-decay of 130Pr to 130Ce suggests the existence of three β-instable isomeric states in 130Pr, while only one half-life T
1/2 = 40(4) s has been measured. Based on the present work and low-lying excited states in neighbouring odd-mass nuclei, the
spins and parities of isomeric states in 130Pr are proposed to be 2+, (4,5)+ and (7,8±). The ground state in 130Pr is still undetermined.
Received: 20 August 2001 / Accepted: 6 November 2001 相似文献
10.
R. Kumar D. Mehta N. Singh H. Kaur A. Görgen S. Chmel R.P. Singh S. Murlithar 《The European Physical Journal A - Hadrons and Nuclei》2001,12(1):5-8
The band structures built on the 5- isomeric state ( T
1/2 = 3.46 m) in the doubly odd 130Cs nucleus have been established up to I = 24? via the 124Sn(11B, 5n)130Cs reaction. The previously observed bands based on the πh
11/2⊗νh
11/2, πg
7/2⊗νh
11/2 and πd
5/2⊗νh
11/2 configurations and a positive-parity side band with multiple connections to the α = 0 signature partner of the yrast πh
11/2⊗νh
11/2 band have been extended to higher spins. A new band based on the πh
11/2⊗νg
7/2 configuration is observed. The yrast πh
11/2⊗νh
11/2 band exhibits anomalous signature splitting whose magnitude decreases up to spin 15 and then increases without restoring
the normal signature splitting.
Received: 20 February 2001 / Accepted: 9 May 2001 相似文献
11.
F. Becker W. Korten F. Hannachi P. Paris N. Buforn C. Chandler M. Houry H. Hübel A. Jansen Y. Le Coz C.F. Liang A. Lopez-Martens R. Lucas E. Mergel P. H. G. Schönwasser C. Theisen 《The European Physical Journal A - Hadrons and Nuclei》1999,4(2):103-105
The atomic nucleus 74Kr has been investigated using combined conversion-electron (CE) and γ-ray spectroscopy. In order to confirm the existence
of the expected low-lying isomeric 0+
2 state, the possibility of an electric-monopole (E0) decay to the ground state was examined. The observation of an E0 transition
at 508 keV allowed the determination of the mixing between coexisting prolate and oblate shapes.
Received: 16 November 1998 相似文献
12.
M. L. Li S. J. Zhu S. D. Xiao X. L. Che Y. N. U Y. J. Chen H. B. Ding L. H. Zhu G. S. Li S. X. Wen X. G. Wu 《The European Physical Journal A - Hadrons and Nuclei》2006,28(1):1-4
High-spin states of 137La have been investigated with the reaction 130Te(11B, 4n) at a beam energy of 50MeV. The level scheme of 137La has been expanded with spin up to 33/2ℏ. Several new bands have been found in this nucleus. A band crossing in the band
based on the 17/2- level has been observed at a rotational frequency of ℏω ∼ 0.48MeV. From systematic comparison, this band crossing probably
originates from the alignment of protons. One of the bands with strong M1 transitions is proposed as a collective oblate band ( γ ∼ -60°). 相似文献
13.
C. Wheldon P.M. Walker R. D'Alarcao P. Chowdhury C.J. Pearson E.H. Seabury I. Ahmad M.P. Carpenter D.M. Cullen G. Hackman R.V.F. Janssens T.L. Khoo D. Nisius P. Reiter 《The European Physical Journal A - Hadrons and Nuclei》1999,5(4):353-355
A t
1/2 > 1 ms, high-K isomeric state feeding a strongly coupled rotational band has been identified following the deep inelastic
reaction 238
92U +186
74W at 1600 MeV. Examination of γ-ray and X-ray data combined with a g-factor analysis derived from in-band branching ratios
suggests the assignment of the new states to the neutron-rich nucleus 185
73Ta.
Received: 11 May 1999 相似文献
14.
A. M. Bizzeti-Sona P. Blasi P. A. Mandò P. Passalacqua A. A. Stefanini 《Zeitschrift für Physik A Hadrons and Nuclei》1991,338(2):157-162
Conversion electrons, and X rays from102Rhm (6+,T
1/2=1057 d) have been studied. An electromagnetic branch (2.3±0.3) ·10–3 feeding the102Rh first excited state has been observed in the 6+ isomeric decay. The excitation energy of the 6+ isomer turns out to be 140.7 keV above the 2– ground state.We wish to thank P. Del Carmine, M. Ottanelli, and A. Pecchioli for their skillful collaboration during the measurements and the Technical Staffs of LNS and LNL for operation of the Tandem Accelerators. 相似文献
15.
R.P. Singh R.K. Bhowmik S.S. Ghugre S.B. Patel 《The European Physical Journal A - Hadrons and Nuclei》2000,7(1):35-40
High spins states in 99Rh were populated via the 66Zn(37Cl, 2p2n)99Rh reaction at an incident beam energy of 130 MeV. Seventeen new transitions have been observed in the present study and the
level scheme has now been extended up to a spin of J∼ 25ħ and an excitation energy of about E
x∼ 10 MeV. The observation of a positive parity E2 cascade based on the 9/2+ isomeric level is suggestive of collective behaviour in this nucleus up to high spins. Spherical shell model (within restricted
model space) and Cranked shell model calculations were performed to obtain an insight into the observed level structure. The
new collective band observed up to a spin of J∼ 25ħ is suggested to be based on (πg
9/2
3) ⊗ (νg
7/2
2) quasi-particle excitations.
Received: 12 July 1999 / Revised version: 14 September 1999 相似文献
16.
T. Bäck B. Cederwall K. Lagergren R. Wyss A. Johnson P. Greenlees D. Jenkins P. Jones D.T. Joss R. Julin S. Juutinen A. Keenan H. Kettunen P. Kuusiniemi M. Leino A.-P. Leppänen M. Muikku P. Nieminen J. Pakarinen P. Rahkila J. Uusitalo 《The European Physical Journal A - Hadrons and Nuclei》2003,17(1):1-5
The decay out of the πh
11/2νh
11/2 band to the known low-energy levels in 132La was studied using the reaction 100Mo + 36S at 160 MeV beam energy. The low-energy level scheme has been further developed and unambiguous spin and parity values have
been assigned to the levels connecting the band to the 6- isomeric state. According to the new level scheme the spins in the πh
11/2νh
11/2 band are shifted up by one unit compared to the earlier tentative experimental values. The obtained new spins prove the existence
of signature inversion in 132La and give further support to the spin assignments made for the πh
11/2νh
11/2 bands in the neighbouring odd-odd La isotopes from level energy systematics.
Received: 7 May 2002 / Accepted: 31 October 2002 / Published online: 17 January 2003
RID="a"
ID="a"e-mail: timar@atomki.hu
RID="b"
ID="b"Present address: Dipartimento di Matematica e Fisica, Università di Camerino, via Madonna delle Carceri, I-62032 Camerino, Italy.
Communicated by J. ?yst? 相似文献
17.
D. Rudolph R. Hoischen M. Hellström S. Pietri Zs. Podolyák P. H. Regan A. B. Garnsworthy S. J. Steer F. Becker P. Bednarczyk L. Cáceres P. Doornenbal J. Gerl M. Górska J. Grebosz I. Kojouharov N. Kurz W. Prokopowicz H. Schaffner H. J. Wollersheim L. -L. Andersson L. Atanasova D. L. Balabanski M. A. Bentley A. Blazhev C. Brandau J. R. Brown C. Fahlander E. K. Johansson A. Jungclaus 《The European Physical Journal A - Hadrons and Nuclei》2008,36(2):131-138
The fragmentation of a 550MeV/u primary beam of 58Ni on a 9Be target has been used to measure time- and energy-correlated γ decays following the implantation of event-by-event discriminated
secondary fragments into a 9Be stopper plate. A new isomeric γ decay with T
1/2 = 14(
) ns and E
γ = 646.2(2) keV is observed and attributed to the decay of the yrast 3/2- state in 53
27Co26 . This short-lived isomeric state has been populated by means of nuclear reactions during the stopping process of the secondary
fragments. The experimental findings are discussed in the framework of large-scale spherical shell model calculations in conjunction
with isospin symmetry-breaking residual interactions for the A = 53 , T
z = ±1/2 mirror nuclei 53Co and 53Fe . 相似文献
18.
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 European Physical Journal A - Hadrons and Nuclei》2007,33(2):193-212
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 . 相似文献
19.
P.J.R. Mason D.M. Cullen C. Scholey A. Dewald O. Möller H. Iwasaki T. Pissulla W. Rother J.A. Dare P.T. Greenlees U. Jakobsson P.M. Jones R. Julin S. Juutinen S. Ketelhut M. Leino N.M. Lumley B. Niclasen M. Nyman P. Peura A. Puurunen P. Rahkila P. Ruotsalainen J. Sorri J. Sarén J. Uusitalo F.R. Xu 《Physics letters. [Part B]》2010
The lifetime of an excited state above a weakly populated isomer in the proton-unbound odd–odd nucleus 144Ho has been measured using the recoil distance Doppler shift method. This measurement represents the first differential-plunger lifetime measurement to utilize recoil-isomer tagging. The first excited Iπ=(10+) state above the two-quasiparticle πh11/2⊗νh11/2(8+) isomer was determined to have a lifetime of τ=6(1) ps. Potential energy surface calculations, based on the configuration-constrained blocking method, predict the isomeric state to have γ -soft triaxial-nuclear shape with |γ|≈24°. The lifetime of the (10+) state can be understood from these calculations if there is a degree of rotational alignment in this band, with the K value being lower than the bandhead spin. However, the validity of the K quantum number with large predicted triaxiality and gamma softness requires further theoretical study. 相似文献
20.
G.D. Jones P.A. Butler T.H. Hoare P.M. Jones 《The European Physical Journal A - Hadrons and Nuclei》1998,2(2):129-141
The low spin states of 223Ra have been populated via α-decay from 227Th which was itself produced following β− decay of an 227Ac source. α–γ and α−e
K,L,M angular correlation measurements have been analysed using the correct ground state spins of 227Th(=1/2+) and 223Ra(=3/2+) for the first time.
The analysis has allowed unique Jπ values to be assigned to almost all levels below 400 keV excitation in 223Ra.
Values of (g
K−g
R)/Q
0 have been deduced for several members of the K= 3/2± bands (for the first time in an odd N nucleus in this mass region) allowing estimates of g
K and g
R to be extracted. The values of g
K and g
R are not significantly different for the positive and negative parity band members and tend to support other strong evidence
that stable octupole deformation exists in 223Ra at low excitation energies.
Received: 17 November 1997 / Revised version: 8 January 1998 相似文献