共查询到20条相似文献,搜索用时 31 毫秒
1.
K. S. Toth J. C. Batchelder D. M. Moltz J. D. Robertson 《Zeitschrift für Physik A Hadrons and Nuclei》1996,355(1):225-226
Theα decay of the new isotope180Pb was observed in40Ca bombardments of144Sm:E α = 7.23(4)MeV, and,T 1/2=(4 ?2 +4 )ms. With this decay energy and the known mass of176Hg, the mass excess of180Pb was calculated to be ?1.98(5)MeV. 相似文献
2.
P. Misaelides P. Tidemand-Petersson U. J. Schrewe I. S. Grant R. Kirchner O. Klepper I. C. Malcolm P. J. Nolan E. Roeckl W. -D. Schmidt-Ott J. L. Wood 《Zeitschrift für Physik A Hadrons and Nuclei》1981,301(3):199-208
Sources of187Pb were produced by the142Nd(48Ti, 3n)187Pb reaction followed by online mass separation of the products. Measurements ofγ-γ andα-γ coincidences and half-lives were performed. Twoα-emitting states in187Pb were found with half-lives of 15.2±0.3 s and 18.3±0.3 s, respectively. Theα-γ coincidences yielded excitation energy and possible spin values for a few levels in183Hg. Gamma-transitions in187Tl were identified and a level scheme for187Tl is proposed on the basis of the coincidence relationships and the level systematics of the heavier odd-thallium isotopes. 相似文献
3.
M. Ionescu-Bujor A. Iordăchescu E. A. Ivanov G. Pascovici D. Ploştinaru V. Sabaiduc 《Zeitschrift für Physik A Hadrons and Nuclei》1990,336(3):291-296
The two short-lived isomeric states in112In have been reinvestigated by means of the112Cd(d, 2n) and109Ag (α, n) reactions. Measurements of delayed X- andγ-ray, lifetime and TDPAD spectra have been performed. A 6.32(3) keVγ-ray has been identified in the isomeric decay and anM1 multipolarity has been assigned to it on the basis of the measured internal conversion coefficients:α L =196(39) andα tot=231(35). TheE1+M2(δ =+0.24(4)) andE2 multipolarities have been determined for the 263 and 188 keV transitions deexciting the 8?(T 1/2=2.82(2) μs) and 7+ (T 1/2=0.93(2) μs) isomeric states, respectively. A revised isomeric decay scheme is presented. 相似文献
4.
U. J. Schrewe E. Hagberg H. Schmeing J. C. Hardy V. T. Koslowsky K. S. Sharma 《Zeitschrift für Physik A Hadrons and Nuclei》1983,310(4):295-300
The new isotope164Ta (T 1/2=13.6(2)s) was produced in the127I(40Ca, 3n) reaction and transported to a measuring station by helium jet. Decay properties were observed withα, γ, andγ-γ spectroscopy. TheZ assignment of the new isotope was based ongg-X-ray coincidence measurements. The mass assignment was deduced from measured excitation functions. The twoγ rays assigned to the new activity most likely originate from the 4+→2+→0+ decay sequence in164Hf. A smallα branch, ≦0.016(5)%, with anα decay energy ofE α=4,625(15) keV was found and assigned to the decay of164Ta. The deduced upper limit of theα width for this branch,W α≦0.6(2), is in accordance with those known for neighbouring nuclei. 相似文献
5.
P. Mohr H. Abele V. Kölle G. Staudt H. Oberhummer H. Krauss 《Zeitschrift für Physik A Hadrons and Nuclei》1994,349(3-4):339-340
Theα-α differential cross sections are analyzed in the optical model using a double-folded potential. With the knowledge of this potential bound and resonance-state properties ofα-cluster states in8Be and12C as well as astrophysical S-factors of4He(α,γ)8Be and8Be(α,γ)12C are calculated. Γγ-widths and B(E2)-values are deduced. 相似文献
6.
J. Wauters P. Dendooven P. Decrock M. Huyse R. Kirchner O. Klepper G. Reusen E. Roeckl P. Van Duppen 《Zeitschrift für Physik A Hadrons and Nuclei》1992,342(3):277-282
Theα-branching ratios (b α ) of192,190,188Pb are measured using mass-separated sources. Different experimental set-ups are used — one detector as well as two detector set-ups — thereby detecting theα particles from the parent and/or viaα decay formed daughter nuclei, theβ-delayed gamma radiation from the parent and/or viaβ decay formed daughter nuclei and the Tl KX rays from electron capture decay. Values forb α of 6.2(6) 10?5 and 4.0(4) 10-3 were found for192,190Pb respectively. For188Pb, limits on theb α values were obtained: 0.03<b α <0.10. A careful analysis of the previously reportedb α values showed that the discrepancies in theb α values were not due to inadequate correction procedures, as was suggested, but to experimental uncertainties in the efficiency determination of the different detection set-ups and to an unreliableβ-decay scheme for188Pb. Theb α obtained in this work show that the leadα decay is not faster than the Hgα decay and that there is no need to assume a disappearance of theZ=82 shell closure halfway betweenN=82 andN=126. 相似文献
7.
T. Lönnroth P. Ahonen R. Julin S. Juutinen A. Lampinen A. Pakkanen S. Törmänen W. Trzaska A. Virtanen 《Zeitschrift für Physik A Hadrons and Nuclei》1990,337(1):11-14
The isomeric decay of theT 1/2=94 us isomeric state in201Hg was studied in beam via the reaction198Pt(α, n). Gamma-ray and conversion-electron spectra were recorded. From the conversion coefficients, the multipolarities of the two depopulating transitions were determined to beM 2 + 10%E 3 andE 2, respectively. These assignments give the depopulating transitions to be 13/2+ → 9/2? and 9/2? → 5/2?, and these thus substantiate the previous suggestion that the isomeric state hasJ π=13/2+. For the 13/2+ → 9/2? M 2 transition a detailed study ofE 3 andM 4 admixed amplitudes was done. The microscopic properties of the 13/2+ and 9/2? states are discussed, and a comparison to the corresponding ones in199,203,205Hg is made. 相似文献
8.
T. A. Khan W. D. Lauppe K. Sistemich H. Lawin G. Sadler H. A. Selic 《Zeitschrift für Physik A Hadrons and Nuclei》1977,283(1):105-120
Theβ-decay of100Y has been investigated at the gas filled recoil separator JOSEF by means ofγ-ray and conversion electron spectroscopy. Twoβ-decay modes, of half lives 0.94±0.03 s and 0.55±0.15 s, have been observed. Using Xγ-, Xce-, γγ- andγce-coincidences the level scheme of100Zr has been constructed. An excited 0 2 + state at 331.3 keV has been discovered in this nucleus. Theβ-decay from the 0.55 s decay mode in100Y shows a strong preference for the ground state compared to the 0 2 + state in100Zr. The structure of100Zr and the nature of the 0 2 + level is discussed in the light of the present results. 相似文献
9.
F. Brandolini D. Bazzacco A. M. I. Haque M. Ionescu-Bujor P. Pavan M. De Poli R. V. Ribas C. Rossi-Alvarez 《Zeitschrift für Physik A Hadrons and Nuclei》1995,353(2):141-144
Theg-factors of the 2 1 + and 4 1 + states in198,200,202Hg were simultaneously measured by means of the transient-field perturbed angular correlation method in Coulomb excitation using multi-isotopic targets and thin polarized Gd foils as ferromagnetic host. Theg(2 1 + ) andg(4 1 + ) were found identical within errors in198, 200Hg, while in200Hg lowerg-factor values have been determined. The experimentalg-factors were compared with the predictions of the pairing-plus-quadrupole, dynamical deformation and interacting boson models. 相似文献
10.
C. G. Lindén I. Bergström J. Blomqvist K. -G. Rensfelt H. Sergolle K. Westerberg 《Zeitschrift für Physik A Hadrons and Nuclei》1976,277(3):273-290
Using the204Hg(α, 3n) reaction withα-particles of about 40 MeV, we have proved by applying nowadays conventionalγ-ray spectroscopy in-beam technique, that there are two isomeric states in205Pb at the excitation energies 5,161.3 and 3,195.5 keV having the half-lives 71±3 and 217±5 ns, respectively. These isomeric states have spins and parities 33/2+ and 25/2? and are mainly due to thei 13 2/?3 andi 13 2/?2 p 1 2/?1 configurations, respectively. This conclusion is supported by the experimentalg-factors of these states being ?0.159±0.008 and ?0.0676±0.0011, respectively. It is furthermore shown that theE2 effective neutron charge is the same forE2 transitions from the 33/2+ state in205Pb and from the 12+ state in206Pb as required by the assumption that the208Pb core is responsible for the totalE2 strength of the neutron holes, and that these states are due to thei 13 2/?3 andi 13 2/?2 configurations. The calculatedB(E3) values ofE3 transitions from isomeric states in205Pb and206Pb agree reasonably well with the experimental values as expected from the assumption that theE3-strength should come from particle coupling to the octupole states of the208Pb core. The energies of the six most well established excited states in205Pb with angular momenta in the region 19/2–33/2 were calculated using empirical single-particle energies, empirical two-particle interactions and angular momentum algebra. The average deviation between experimental and calculated energies is ?3 keV and the root mean square deviation 6 keV as compared to the uncertainty ± 5 keV in the nuclear masses used in the calculation. For the orbits concerned the shell model is thus valid with an extremely high precision. The contribution of effective three-particle interaction in these orbits must consequently be less than about 5 keV. 相似文献
11.
R. Majumdar 《Zeitschrift für Physik A Hadrons and Nuclei》1985,320(2):307-309
The three proton-hole states ?2d5/2, 1g7/2 and 1g9/2 are found to be fragmented as a result of coupling of these states with the 3?, 5?, 2+, 4+ and 6+ collective states of208Pb. The excited states in208Pb (t,α) reaction can be quantitatively explained in terms of altered 2d5/2, 1g7/2 and 1g9/2 states with the hole-core coupling model. 相似文献
12.
R. Broda M. Behar P. Kleinheinz P. J. Daly J. Blomqvist 《Zeitschrift für Physik A Hadrons and Nuclei》1979,293(2):135-149
The level structures of theN=82 andN=83 nuclei147Tb and148Tb have been studied by means of (α, 8n) and (α,7n) reactions induced by 68 to 110 MeVα particle bombardments of151Eu targets. In-beam conversion electron measurements have established that isomers withT 1/2=4.8(6)ns in147Tb andT 1/2=22(1)ns in148Tb decay byM2+E3 transitions to the ground states. The measuredB(E3) values show that the isomeric states arise from the coupling of the valence nucleon(s) to the146Gd core octupole. Particlephonon coupling in these nuclei and in the one-neutron nucleus147Gd is discussed and compared with well known cases involving the208Pb core. The higher lying yrast states in the two Tb nuclei are described as shell-model particle-hole excitations using empirical single particle energies and nucleon-nucleon interactions. 相似文献
13.
G. Menzen K. Sistemich G. Lhersonneau H. Gietz 《Zeitschrift für Physik A Hadrons and Nuclei》1987,327(1):119-126
Theβ ? decay of the longer-lived isomer in100Nb has been studied at the fission-product separator JOSEF. Measurements ofγ-ray singles spectra, ofγ-γ coincidences and ofγ-γ angular correlations have been performed. A value oft 1/2=2.99(11)s has been determined for the isomer which probably hasI π=4+ or 5+. A scheme of the levels of100Mo which are populated in the decay of this isomer has been established. Information on the spins of several states of100Mo has been obtained. Thus,I=0 levels have been identified at 1,505, 2,038 and 2,087 keV. The mixing ratios have been determined for the 22 +→21 + and 23 +→21 + transitions. The results provide evidence for a vibrational structure of100Mo with separate bands based on the ground state and on the first excited 0+ level. 相似文献
14.
R. Hingmann H. -G. Clerc C. -C. Sahm D. Vermeulen K. -H. Schmidt J. G. Keller 《Zeitschrift für Physik A Hadrons and Nuclei》1982,309(1):27-31
Theα-decays of199Rn (E α = (6.989±0.010) MeV,T 1/2>300ms) and of199m Rn (E α = (7.060±0.015) MeVT 1/2=(61 ?2 +32 ) ms) were identified by anα-α-correlation method. They proceed via separated decay paths to195Po and195m Po, respectively. The spins of the involved states are discussed by aid of the shell model, and a tentative spin assignment is given. 相似文献
15.
R. Julin J. Kantele M. Luontama A. Passoja T. Poikolainen A. Bäcklin N. -G. Jonsson 《Zeitschrift für Physik A Hadrons and Nuclei》1980,296(4):315-318
Absolute rates ofE0 andE2 transitions depopulating 0 2 + and 0 3 + states in112Cd and114Cd have been determined using conversion-electron andγ-ray spectroscopy, and double Coulomb excitation. The collectivity of these states is established and discussed. 相似文献
16.
Y. Yamazaki R. K. Sheline D. G. Burke 《Zeitschrift für Physik A Hadrons and Nuclei》1978,285(2):191-201
The nuclear structures of193Ir and195Ir have been studied using the194Pt(t, α) and196Pt(t, α) reactions. Levels up to ~2MeV in excitation energy were studied with a resolution of ~13keV (FWHM) and spectroscopic strengths were extracted. The low-lying states in193Ir have been interpreted in terms of both the Nilsson and the rotation-vibration models including Coriolis, particle-vibration and rotation-vibrational couplings. The previously assigned 3/2+ [402], 11/2? [505], 1/2+[400] and 1/2+[411] bands were populated and candidates for the 5/2+ [402] and 7/2+ [404] bandheads were observed. TheK 0 +2 gamma vibration based on the ground state was populated because it is mixed with the 7/2+ [404] state. Surprisingly, there was no significant difference between the stripping and pick-up strengths for the low-lying states in193Ir, suggesting that the equilibrium nuclear shape of193Ir has large overlaps with the shapes of both192Os and194Pt. The nuclear level structure of195Ir appears to be similar to those of the lighter iridium isotopes. 相似文献
17.
P. Zeyen K. Euler V. Grafen C. Günther M. Marten-Tölle P. Schüler R. Tolle 《Zeitschrift für Physik A Hadrons and Nuclei》1986,325(4):451-456
Low lying levels in203Hg and205Hg were studied with the (d, p) deuteron break-up reaction atE d=14 and 18 MeV. Gamma-rays and conversion-electrons were measured in coincidence with protons. In addition delayed spectra were recorded with us and ms beam pulsing. Thei 13/2 neutron hole state was identified in205Hg and confirmed in203Hg. The known level structure of205Hg below 2 MeV is confirmed and extended. For203Hg we observe theγ-decay of several levels below 1.5 MeV, which were previously known from transfer reactions. 相似文献
18.
The level scheme of the very neutron rich nucleus 106 42 Mo64 has been studied for the first time through theβ decay of106Nb. Six new excited states were observed inγ singles andγ-γ coincidence experiments in addition to the 2+, 4+ and 6+ members of the ground state band. The excitation energies and the deexcitation pattern suggest the interpretation of the levels at 710, 885 and 956 keV as the 2 2 + , 3 1 + and 0 2 + states, respectively. The data support the assumption of a non-axial deformation of106Mo. A half-life of (1.02±0.05) s has been determined for theβ decay of106Nb. 相似文献
19.
G. Münzenberg P. Armbruster G. Berthes H. Folger F. P. Heßberger S. Hofmann J. Keller K. Poppensieker A. B. Quint W. Reisdorf K. -H. Schmidt H. -J. Schött K. Sümmerer I. Zychor M. E. Leino R. Hingmann U. Gollerthan E. Hanelt 《Zeitschrift für Physik A Hadrons and Nuclei》1987,328(1):49-59
The experiment having led to the discovery of first isotopes of element 108, as published previously in Short Notes to this Journal [1, 2] are described and discussed in a final paper. Two isotopes of element 108 were produced by complete fusion of207Pb and208Pb, respectively, with58Fe. Both isotopes areα-emitters. For the isotope with mass 265 threeα-decay sequences were observed. Theα-decay energy is (10.36±0.03) MeV, the half-life (1.8 ?0.7 +2.2 ) ms. For the isotope with mass 264, which is the heaviest doubly even isotope known at present, the decay sequence of one atom was found. The measured half-life is (76 ?36 +364 ) μs. Our experimental results point towards an enhanced stability of the heaviest elements against spontaneous fission, which was already observed for element 106. 相似文献
20.
J. R. Van Hise D. C. Camp R. A. Meyer 《Zeitschrift für Physik A Hadrons and Nuclei》1975,274(4):383-389
A precision study of the decay of134Cs g and134Cs m has been made, using ordinary Ge(Li) spectrometers and ā Compton-suppression spectrometer. The logft value of the second forbidden nonuniqueβ-decay to134Xe has been measured to be 13.0±0.2. TheM4γ-ray transition in134Csm(8?) decay has been measured to haveα K= 73±7 and a hindrance of 7.0 over the Moskowski estimate. This is discussed in terms of the level configurations and the analogous transition in133Xe. A new intensity limit of 2×10?6 has been set for the zero-phonon transition between the 4+ and 2+ members of the two-phonon triplet. This leads to an upper limit forB(E2)4→2′, greater than 905. This and the more preciseγ-ray intensity values are discussed in relation to presently available nuclear models. 相似文献