共查询到20条相似文献,搜索用时 31 毫秒
1.
E. Andersson P. Herges H. V. Klapdor I. N. Wischnewski 《Zeitschrift für Physik A Hadrons and Nuclei》1981,299(2):105-111
High spin states in108Sn have been investigated using the92Mo(19F,p2nγ)108Sn reaction. In-beam measurements ofγ-γ-coincidences,γ-ray excitation functions andγ-ray angular distributions were performed with Ge(Li)-detectors, one of which had a Nal Compton suppression shield. A level scheme for108Sn has been constructed up to anI π=(14?) state. 相似文献
2.
P. Betz E. Bitterwolf A. Burkard F. Glatz F. Heidinger Th. Kern R. Lehmann S. Norbert H. Röpke C. Schneider J. Siefert 《Zeitschrift für Physik A Hadrons and Nuclei》1982,309(2):163-176
Particleγ-ray coincidences have been measured in the28Si (d,pγ) reaction at 6.5 and 7 MeV bombarding energy, in the26Mg (α,nγ) reaction at 12, 14 and 15 MeV, and in the27A1 (τ,pγ) reaction at 9 MeV. Theγ-decay has been observed for all bound states of29Si and for 56 unbound states up to 12,960 KeV excitation energy. Particleγ-ray angular correlations were measured in the28Si (d,pγ) reaction at 6.5 MeV and in the26Mg (α,nγ) reaction at 12 MeV. Spin (-parity) assignments or restrictions were obtained for nearly all bound states and some high-spin states above the binding energy. The assignment of mirror levels in29Si and29P has been extended to 8.2 MeV excitation energy. The excitation energies of 41 positive-parity states are reproduced by shell model calculations. The possible existence of aK π=5/2+ band with prolate deformation is discussed. 相似文献
3.
I. Thorslund C. Fahlander A. Bäcklin B. Kotliński D. Cline A. T. Renalds E. G. Vogt 《Zeitschrift für Physik A Hadrons and Nuclei》1992,342(1):35-42
The lifetimes of five states in the ground band, from spin 6+ up to spin 14+, and of all even states in the gamma band up to spin 12+, have been measured in166Er using the recoil distance method. The reduced electric quadrupole transition probabilities have been determined from the measured lifetimes using previously measured branching ratios, and the mixing between the ground band and theγ-band has been studied. The transitional electric quadrupole moments for the ground band and theγ-band have been deduced and are discussed. 相似文献
4.
C. Morand B. Berthet M. Agard J. F. Bruandet A. Giorni F. Glasser J. P. Longequeue Tsan Ung Chan 《Zeitschrift für Physik A Hadrons and Nuclei》1976,278(2):189-199
The68Ga nucleus has been studied via the reactions65Cu(α, nγ)68Ga atE α=12–21 MeV and66Zn(α, p nγ)68Ga atE α=25–40 MeV. The level scheme has been established by means of relative yield functions, electronic timing measurements, prompt and delayedγ-γ coincidences, angular distributions and directional orientation coÏncidences. Spins up to 11+ were assigned to levels up to 4 MeV excitation and the higher ones were interpreted by coupling a67Ga core with a (v 1 g9/2) neutron. 相似文献
5.
J. Danière R. Béraud M. Meyer R. Rougny J. Genevey-Rivier J. Tréherne 《Zeitschrift für Physik A Hadrons and Nuclei》1977,280(4):363-369
Levels of106Cd, populated by104Pd(α, 2nγ)106Cd have been studied measuring direct and delayedγ-ray spectra,γ-γ coincidences andγ-ray angular distributions. A decay level scheme is proposed including states up to 4659.8 keV. IntenseE2 transition cascades have been observed. The half-life of an isomeric level located at 4659.8 keV has been measured:T 1/2= 62±6ns. Nuclear Reactions 104Pd(α, 2nγ),E α=31MeV; measuredE γ,I γ,γ-γ coinc, σ(θ)T 1/2.106Cd deduced levels,J, π, Enriched targets. Ge(Li) detectors. 相似文献
6.
I121 was produced by bombarding a target of enriched Te122 with deuterons of 25 MeV. Theγ rays associated with the decay of I121 have been investigated using a Ge(Li) detector and a Ge(Li)-NaI coincidence set up. 58γ transitions ranging from 212.5 to 1841.8 keV have been identified. A decay scheme for the I121→Te121 decay which accounts for 50 of the observedγ transitions is proposed. 相似文献
7.
F. A. Beck J. Dudek B. Haas J. C. Merdinger A. Nourreddine Y. Schutz J. P. Vivien Ph Hubert D. Dassié G. Bastin L. Nguyen J. P. Thibaud W. Nazarewicz 《Zeitschrift für Physik A Hadrons and Nuclei》1984,319(2):119-132
High spin states in the nucleus154Er have been reinvestigated using the123Sb(35Cl, 4n) reaction and a variety of spectroscopic techniques including excitation functions,γ-γ coincidences,γ angular distribution and linear polarization measurements. From the measured energies, relative intensities and transition multipolarities a new level scheme has been deduced up to an excitation energy of ~12 MeV and spin 36. An interpretation of the experimental results is given in terms of the deformed Woods-Saxon orbitals. Gigantic backbending (superdeformation) effect is studied theoretically within the cranking model. 相似文献
8.
Silas R. Beane Zohreh Davoudi Martin J. Savage 《The European Physical Journal A - Hadrons and Nuclei》2014,50(9):1-9
The level scheme above the proton threshold in 26Si is crucial for evaluating the 25Al(p, γ)26Si stellar reaction, which is important for understanding the astrophysical origin of the long-lived cosmic radioactivity 26Al(T 1/2 = 7.17 × 105 y) in the Galaxy. The excited states in 26Si have been studied using an in-beam γ-ray spectroscopy technique with the 24Mg(3He, nγ)26Si reaction. γ-rays with energies up to 4.6 MeV emitted from excited states in 26Si have been measured using large volume HPGe detectors. The spin-parity of one of the most important states reported recently at 5890.0keV has been assigned as 0+ by γ-γ angular correlation measurements in this work. 相似文献
9.
S. André D. Barnéoud C. Foin J. Genevey J. A. Pinston B. Haas J. P. Vivien A. J. Kreiner 《Zeitschrift für Physik A Hadrons and Nuclei》1989,334(3):247-253
High-spin states in205Bi, populated in the205Tl(α, 4n) reaction with bombarding energies around 50 MeV have been studied usingγ-ray spectroscopic techniques. Spins and parities have been assigned on the basis of angular distribution andγ-ray linear polarization measurements. States with spins up to 39/2+ and excitation energies around 6 MeV have been identified. Calculations using the empirical shell model have been performed in order to assign configurations. 相似文献
10.
J. M. Thirion G. Chouraqui Th. Muller M. Port 《Zeitschrift für Physik A Hadrons and Nuclei》1984,317(3):329-333
The61Zn decay scheme and level properties have been investigated up to the 2,269.6 keV level by the58Ni(α, n γ)61Zn reaction using enriched targets. Excitation functions,γ ray spectra andn-γ coincidence spectra have been measured as well as angular distributions and angular correlations in Litherland II geometry. Gamma ray energies, excited state spins andγ ray branching ratios have been determined. 相似文献
11.
M.H. Ernst 《Physics Reports》1981,78(1):1-171
The present paper is devoted to the subject of photonuclear reactions of the type (γ, p), (γ, n), (γ, np), (γ, nn), (γ, pp) as well as nucle on capture reactions as (p, γ) at intermediate photon energies. The theoretical part of this paper reviews and extends earlier calculations of the authors up t gamma energies of Eγ ≈ 400 MeV. The paper is not intended to give a review on different theoretical approaches which have been underta ken in the past. Instead, emphasis is put on the dynamical aspects of the photonuclear reactions in order to see which elementary processes govern the reactions at different photon energies. In view of the success of the present treatment up to Eγ ≈ 120 MeV photon energy, we tempt the predictive power of the model up to photon energies of Eγ ≈ 400 MeV for the reactions in 4He and 16O. 相似文献
12.
P. Aguer G. Bastin J. P. Thibaud D. Barneoud J. Boutet C. Foin 《Zeitschrift für Physik A Hadrons and Nuclei》1978,285(1):59-66
High-spin states in154Er have been populated by bombarding147Sm and148Sm with12C particles. Excitation functions, lifetimes, angular distributions andγ-γ coincidences were measured. AT 1/2=35ns isomeric state atE x~3 MeV has been found and is interpreted as a two-quasi-particle state with aligned angular momenta. A cascade of intense individual lines from states with spin up to at least 26 (excitation energy up to 8.543 MeV) was found to feed the isomeric state. The level sequence above this yrast trap exhibits an irregular pattern which cannot be easily interpreted in terms of collective modes. 相似文献
13.
F. Seiffert R. Schwengner G. Winter L. Funke W. Lieberz R. Reinhardt K. P. Schmittgen D. Weil R. Wrzal K. O. Zell P. von Brentano 《Zeitschrift für Physik A Hadrons and Nuclei》1991,340(2):141-153
Excited states of73Se have been investigated up to spin, 21/2 using techniques of in-beamγ-ray spectroscopy in connection with the70Ge(α, n) reaction. Mean lifetimes of 12 levels have been determined applying Doppler-shift andγ-RF-methods. Five different bands have been identified that reflect a variety of different excitation modes. The decoupled 9/2+ band is likely to correspond to an oblate deformation while the 5/2+ band is interpreted as a strongly coupled prolate band built on the Nilsson configuration [422] 5/2+. The 3/2? band is a strongly coupled band built on the [301] 3/2} configuration.Nuclear reactions:70Ge(α,n),E=14, 16, 18, 19, 20MeV; measuredE γ,I γ,σ(E γ,θ),γγ-coin, linear polarization, DSA,γ(t).75Se deduced levels,I, π, τ, δ(E2/M1), B(σλ). Enriched targets, Ge detectors. 相似文献
14.
K. Sümmerer N. Kaffrell H. Otto P. Peuser N. Trautmann 《Zeitschrift für Physik A Hadrons and Nuclei》1978,287(3-4):287-297
Theβ ? — andγ-activities of 18.4 min104Tc have been studied with singles and coincidence measurements. Sources were prepared by chemical separation of technetium from the fission products of thermal-neutron-induced fission of235U. A revised level scheme of104Ru up to an excitation energy of 4.26 MeV is proposed. Fromβ-γ coincidence measurements, aQ β-value of 5.62±0.07 MeV has been obtained. 相似文献
15.
Excited states of the137Ce,139Ce,139Nd and141Nd nuclei have been studied using the138Ba(α, 5nγ)137Ce,138Ba(3He, 4nγ)137Ce,138Ba(α, 3nγ)139Ce,140Ce(α, 5nγ)139Nd,140Ce(3He,4nγ)139Nd,140Ce(α, 3nγ)141Nd and142Ce(α, 5nγ)141Nd reactions. Singlesγ-ray spectra,γ —γ coincidence spectra, angular distributions and time distributions ofγ-rays with respect to beam pulses have been measured. Gamma transitions between excited states with spin values up to 21/2, 23/2 or 25/2 have been observed. Isomeric states with T1/2=70 ns have been observed in139Ce at 2631.5 keV (19/2) and in141Nd probably at 2952.0 keV (19/2). The level structure observed in the nuclei studied can be explained if the neutron-holes are coupled to the doubly even core excitations. The coupling of theh 11/2 neutron-hole with the 2+, 4+ and 3? collective excitations are calculated in terms of the weak and intermediate coupling models. The intermediate coupling results seem to be in better agreement with the experimental data. The energies of theree-particle states, being the result of the coupling of theh 11/2 neutron-hole with the two-proton excitations in the core, are well reproduced in the calculations when empirical values of the two-body interaction matrix elements were used. 相似文献
16.
States in34S up to 6 MeV excitation energy, populated by the reaction31P(α, pγ), have been investigated by Doppler shift and line shape analysis andpγ andγγ angular correlation measurements. The strengths of electromagnetic transitions between even parity levels are compared with theoretical predictions of the weak coupling unified model and the many-particle shell model. The experimental evidence for a weak coupling of the single particle motion to vibrational modes is discussed. 相似文献
17.
K. Kayser W. Collin P. Filss S. Guldbakke G. Nolte H. Reich J. O. Trier W. Witschel 《Zeitschrift für Physik A Hadrons and Nuclei》1970,239(5):447-460
In order to obtain data on the photon absorption process between the giant resonance and the meson threshold the cross sections of the reactions12C(γ,n)11C,12C(γ, 2n)10C,39K(γ,n)38Kg, and40Ca(γ,np)38Kg have been determined by the analysis of yield curves at the 140 MeV electron synchrotron of the PTB. Though the (γ,n) cross sections grow small with increasing photon energy they are different from zero up to energies of 60 MeV and above. The cross section of the reaction12C(γ, 2n) is extremely small; its highest value amounts to 0.15% of the highest value of the12C(γ,n) reaction. The measured40Ca(γ,np) cross section is of the order predicted by the naive quasi-deuteron model. The integrated cross sections of the above reactions up to 140MeV are 85±7,0.90±0.10, 139±16, and 76±7MeVmb respectively. 相似文献
18.
Dr. J. Weiss Dr. H. Langhoff Dr. M. Schumacher 《Zeitschrift für Physik A Hadrons and Nuclei》1970,230(4):371-382
Previous investigations of nuclear resonance fluorescence from79Br have been improved by using a Ge-detector. In addition, energies and intensities of theγ transitions initiated by the decay of79Kr have been remeasured. Coincidences between theγ transitions were investigated using two 40 ccm Ge-detectors. 14γ transitions unknown up to the present have been identified. A level scheme having 12 excited states is proposed. Unique assignments of spin and parity to the 7 lowest states became possible by the present and former experimental data. 相似文献
19.
R. Geiger P. von Brentano H. G. Friederichs B. Heits W. Schuh K. O. Zell H. Weigmann A. Berinde 《Zeitschrift für Physik A Hadrons and Nuclei》1974,271(2):129-137
The decay scheme of112Cd has been studied by γ-ray spectroscopy with the110Pd(α, 2nγ) reaction. Spin and parity assignments were made on the basis of coincidence measurements, angular distributions and excitation functions. Twelve new energy levels were established. A vibrational-like positive-parity band up to spin 8+ and a negativeparity side band 5?, (7?), (9?) were found. For the negative-parity states a (vj, vh11/2) configuration is suggested. Nuclear Reactions:110Pd(α,2nγ),E α =15–22.5 MeV; measuredE γ ,E γ , (E,E γ ),E γ (θ),γ-γ- coincidence;112Cd deduced levels,J; enriched target. 相似文献
20.
M. Khaliquzzaman W.K. Dawson H.W. Fielding P.W. Green R.L. Helmer W.J. McDonald G.C. Neilson D.M. Sheppard 《Nuclear Physics A》1984,424(2):191-199
The reaction 55Mn(p, nγ)55Fe has been studied at Ep = 4.0 and 6.0 MeV using a pulsed beam. From the experiments at 6.0 MeV, the energy levels of 55Fe up to an excitation of 3810 keV, their decay scheme and the γ-ray branching ratios have been determined. Levels have been identified for the first time in the (p, nγ) reaction. The results have been compared with those available from the literature. From the 4.0 MeV experiment, the mean lifetime of the 1408 keV level has been determined to be 142.7 ± 6.6 ps by direct timing techniques. 相似文献