共查询到20条相似文献,搜索用时 31 毫秒
1.
W. Günther K. Huber U. Kneissl H. Krieger H. Ries H. Ströher W. Wilke 《Nuclear Physics A》1981,359(2):397-407
The half-lives and yield ratios for the two 241Pu fission isomers have been measured in the 242Pu(γ, n) reaction. The observed half-life for the long-lived isomer is in agreement with previous data, and the existence of a short-lived 34 ± 7 ns isomer in 241Pu could be confirmed. The measured yield ratios are Yiso/Ypr = (9.2 ± 0.8) × 10?5 and Yiso/Ypr = (3.7 ± 0.7) × 10?5, respectively. From a statistical model analysis of the isomeric fission yield ratio, Ylongiso/Yshortiso = 2.5 ± 0.6, a spin assignment for the two isomers is attempted. Possible spin combinations are compared with single-particle shell-model calculations and with available spectroscopic data for the other even-odd Pu isotopes. 相似文献
2.
A.O. Weissenberg O.K. Egorov Z.V. Minervina E.A. Pozharova V.A. Smirnitsky M.I. Dayon S.A. Krylov 《Nuclear Physics B》1976,115(1):55-60
The momenta of ~30 000 charged particles from K+ decays were measured using a magnetic spectrometer with streamer chambers. The ratio R = Γ(Kπ2+)/Γ(Kμ2+) = 0.3355 ± 0.0057 was obtained. Our values for the branching ratios are: (63.18±0.43)% for Kμ2+, (21.18±0.33)% for Kπ2+, (3.33±0.51)% for Kμ3+, (4.99±0.54)% for Ke3+. 相似文献
3.
Yu. M. Gledenov J. Kvitek S. Marinova Yu. P. Popov J. Rigol V. I. Salatski 《Zeitschrift für Physik A Hadrons and Nuclei》1982,306(1):57-61
TheK-internal conversion coefficient of the 205 keV (7/2+→5/2+) transition in107Cd was determined. From the measured value α K =0.0552±0.0009 and the known value of theE2/M1 mixing ratio δ2 a value of 6.3±1.5 was deduced for the penetration parameterλ. Information derived on effective gyromagnetic ratios in the frame of an extreme single particle model is briefly discussed. 相似文献
4.
Measurements of line strengths in the (101) and (111)-(010) bands of 14N16O2 have been made at a resolution of 0.02 cm?1 in the region 2863 to 2934 cm?1. The strength data in the (101) band were analyzed to determine a vibrational band strength and coefficients of the F factor. Each subband for K?1 ≤ 9 was analyzed separately and all the F-factor coefficients in terms of the rotational quantum number, N, were found to be too small to be of significance. However, F was found to be dependent on K?1 and the experimentally determined subband strengths were least-squares fitted to the expression Sv0·F, where Sv0 = 68.3 cm?2 atm?1 at 296 K and F = 1 + (2.899 × 10?3)K?1 + (4.08 × 10?3)K?12 ? (2.34 × 10?4)K?13. The integrated strengths for the (101) and (111)-(010) bands were found to be 70.9 ± 2.3 and 2.7 ± 0.3 cm?2 atm?1 at 296 K, respectively. Also included in this study are measurements of line center positions in the two bands and spin-splittings in the (101) band. Recent frequency measurements of lines with K?1 ≤ 8 in the (101) band have been made at a resolution of 0.0033 cm?1 by V. Dana and J. P. Maillard (J. Mol. Spectrosc.71, 1–4) (1978)) for the region above 2889 cm?1 and our values are in excellent agreement with theirs. Separations of the split lines measured in this work (K?1 ≤ 10) agree well with calculated values using expressions which include the ηaaaaK?14 term with η′aaaa = ?1.70 ± 0.15 × 10?4 cm?1 as derived for the (101) state. Three forbidden (ΔN ≠ ΔJ, ΔK?1 = 0) transitions in the (101) band were observed with their identifications based on the agreement between measured and calculated line positions and strengths. 相似文献
5.
S. F. Biagi M. Bourquin R. M. Brown H. J. Burckhart Ch. Doré P. Extermann M. Gailloud C. N. P. Gee W. M. Gibson R. J. Gray P. Jacot-Guillarmod P. W. Jeffreys T. Modis R. C. Owen J. Perrier K. J. Ragan Ph. Rosselet B. J. Saunders P. Schirato H. W. Siebert V. J. Smith K. P. Streit J. J. Thresher R. Weill A. T. Wood C. Yanagisawa 《Zeitschrift fur Physik C Particles and Fields》1986,31(1):33-38
In a experiment at the CERN SPS charged hyperon beam using incident Ξ?, we have obtained evidence for the production of two Ω* resonances decaying into Ξ?π+ K ?, with the following parameters:M 1=2251±12,Γ 1=48±20 MeV/c2, 78 ±23 events, andM 2=2284±12,Γ 2=26±23 MeV/c2 45±10 events. The first state is also observed as a 4.2σ effect in a subsample which contains an additionalK + orK 0 in the final state. Production cross sections and branching ratios to Ξ* K ? and Ξ? K * are presented. 相似文献
6.
I. N. Vishnevsky S. S. Drapey V. A. Zheltonozhsky A. N. Savrasov V. P. Khomenkov 《Bulletin of the Russian Academy of Sciences: Physics》2014,78(7):576-580
Single γ spectra and K X coincidence spectra from 120Sb decay are measured. The total internal conversion coefficients (ICCs) and those on the K-shell are determined for slowed E1 and E2 transitions in 120Sn. Penetration effects are observed for which the penetration parameters are found to be λ1 (89.9 keV, E1) = 3.6 ± 1.6 and λ1 (197.3 keV, E2) = 6 ± 2. 相似文献
7.
M. V. S. Chandrasekhar Rao G. Sree Krishna Murty K. Radha Krishna S. Bhuloka Reddy G. Satyanarayana C. V. Raghavaiah D. L. Sastry S. N. Chintalapudi 《Zeitschrift für Physik A Hadrons and Nuclei》1990,335(1):25-29
TheK-electron capture probabilities for the 1/2? → 3/2? and 1/2? → 1/2+ transitions in the decay of105Ag were measured for the first time using the sum coincidence method. The experimental PK values were estimated to be 0.824 ± 0.042 and 0.851 ±0.046 for the allowed and first-forbidden beta transitions, respectively in agreement with the theory. The PL experimental values to these two levels were also computed using the experimental PL/PK values reported by earlier authors. These results are also found to be consistent with the theoretical PL values. 相似文献
8.
J. Plch P. Dryák J. Zderadička E. Schönfeld A. Szörényi 《Czechoslovak Journal of Physics》1979,29(10):1071-1083
Combining measurement with the use of a Si(Li) detector and a windowless 4π NaI(T1) detector a new value ofω K(Ag) equal to 0.84±0.02 has been determined. From the measured ratio of the KX-ray and conversion electron emission rates the relative K-capture probabilityP K=0.77±0.015 was calculated. Through analysis of data reported in literature and taking into account the new value ofP K andω K and the results of the international comparison of absolute activity measurements of109Cd, the following decay data were chosen for the calculation of yields:ω K=0.836±0.007;α T=26.4±0.3; αK=11.4±0.3; PK=0.78±0.015. The number of gamma photons per disintegration (gamma-yield) was then determined equal to 0.0365±0.0004; the KX-yield equal to 0.997±0.008; the conversion electrons yield equal to 0.9635±0.0005 and the KX/γ ratio equal to 27.3±0.6. 相似文献
9.
Georg Albrecht Johann Wolfgang Hammer 《Zeitschrift für Physik A Hadrons and Nuclei》1975,273(4):405-410
TheK-fluorescence yieldΩ K of Titanium has been measured using the coincidence method and investigating the electron capture decay of48V. The detectors used have been a Si(Li)- and a Ge(Li)-detector for the X- andγ-rays. The experimental results areP K Ω K =0.2005 ±0.0030 andΩ K (Ti)=0.224±0.003 usingP K =0.896. For the branching ratios of the decay of48V we obtainedEC (3.239) 7.9±0.6%EC (3.224) 2.9±0.4%EC (2.295) 35.6±2.0% Β+ (2.295) 52±1.0% all others 1.6%. Additionally someγ-ray-energies of the decay of48V and the half-life,T 1 2=(16.23 ±0.03)d, have been measured. 相似文献
10.
Hermann Weigmann 《Zeitschrift für Physik A Hadrons and Nuclei》1962,167(5):549-557
TheK-conversion coefficients α K of the nuclear isomers Se77m , Se79m , Ge75m and Ge77m have been measured by detecting theK-röntgen- andγ-radiation from neutron-irradiated Se- and GeO2-samples with the aid of scintillation counters to be α K =0.79±0.06, 7.4±0.6, 1.44±0.13, and 1.2±0.6, respectively. In all cases, the values obtained, are in agreement with those taken from the tables ofRose under the assumption of anE3-transition, thus confirming this assignment which was proposed earlier by other authors. In addition, the cross sectionsσ for inducing the activities by slowed down neutrons have been measured to beσ=22±2, 0.40±0.04, 0.20±0.02, and 0.12±0.03 barns, respectively, and are compared with earlier data of several authors. 相似文献
11.
K. E. G. Löbner 《Zeitschrift für Physik A Hadrons and Nuclei》1968,216(4):372-397
The half-lives of the following intrinsic states in deformed odd-mass nuclei has been measured by delayed coincidences with a time-to-amplitude converter:
- 5/2 5/2+[642] at 86.5 keV in155Gd:T 1/2=6.7±0.3 ns, which results in the determination of theE1,ΔK=1 transition probability to the ground state 3/2 3/2?[521] and first rotational state 5/2 3/2?[521], yielding hindrance factors ofF N ≈5.5 and ≈1.8 (F W =3.1×104 and 2.3×104) respectively.
- (3) 5/2 5/2?[512] at 191.4 keV in169Yb:T 1/2=3.35±0.15 ns and at 122.39 keV in171Yb:T 1/2=265±20 ns which results in the determination of the transition probabilities of theE1,ΔK=1 transitions to the ground states 7/2 7/2+[633], of theK-forbiddenM1 transitions to the 5/2 and 3/2 1/2?[521] and of theE2 transitions to the 5/2, 3/2 and 1/2 1/2?[521] states in both nuclei.
12.
M.A. White N.W. Granville N.J. Davies L.A.K. Staveley 《Journal of Physics and Chemistry of Solids》1981,42(11):953-965
The heat capacity of the layer compounds tetrachlorobis (n-propylammonium) manganese II and tetrachlorobis (n-propylammonium) cadmium II, (CH3CH2CH2NH3)2MnCl4 and (CH3CH2CH2NH3)2CdCl4 respectively, has been measured over the temperature range 10 K ?T ? 300 K.Two known structural phase transitions were observed for the Mn compound in this temperature region: at T = 112.8 ± 0.1 K (ΔHt= 586 ± 2 J mol?1; ΔSt = 5.47 ± 0.02 J K?1mol?1) and at T =164.3 ± (ΔHt = 496 ± 7 J mol?1; ΔSt =3.29 ± 0.05 J K?1mol?1). The lower transition is known to be from a monoclinic structure to a tetragonal structure, while the upper is from the tetragonal phase to an orthorhombic one. From comparison with the results for the corresponding methyl Mn compound it is deduced that the lower transition primarily involves changes in H-bonding while the upper transition involves motion in the propyl chain.A new structural phase transition was observed in the Cd compound at T= 105.5 ± 0.1 K (ΔHt= 1472.3 ± 0.1 J mol?1; ΔSt = 13.956 ± 0.001 J K?1mol?1), in addition to two transitions that have been observed previously by other techniques. The higher of these transitions(T = 178.7 ± 0.3 K; ΔHt = 982 ± 4 J mol?1 ΔSt = 6.16 ± 0.02 J K? mol?1) is known to be between two orthorhombic structures, while the structural changes at the lower transition (T= 156.8 ± 0.2 K; ΔHt = 598 ± 5 J mol?1, ΔSt = 3.85 ± 0.03 J K?1 mol?1) and at the new transition are not known. It is proposed that these two transitions correspond respectively to the tetragonal to orthorhombic and monoclinic to tetragonal transitions in the propyl Mn compounds.In addition to the structural phase transitions (CH3CH2CH2NH3)2MnCl4 magnetically orders at t? 130 K. The magnetic contribution to the heat capacity is deduced from the heat capacity of the corresponding diamagnetic Cd compound and is of the form expected for a quasi 2-dimensional Heisenberg antiferromagnet. 相似文献
13.
Johann Wolfgang Hammer 《Zeitschrift für Physik A Hadrons and Nuclei》1968,216(4):355-371
The electron capture decay of Mn 54 and Zn 65 was investigated using Na I(Tl)-detectors. Spectroscopic-coincidence techniques were employed to examine theK-electron capture rates of Mn 54 and Zn 65, the branching ratio and positron rate of Zn 65. The experimental results are:P k ω k (Mn)=0.2492±0.0017,P k ω k (Zn)=0.3927±0.0026,EC * /EC 0(Zn)=53.2±1.0/46.8±1.0,γ/β +=35.1±1.7,K 0/β +=27.7±1.5. Thus electron capture to the excited state of Cu 65 occurs to the extent of 52.4±1.0% while electron capture and positron decay to the ground state were found to be associated with 46.1±1.0% and 1.49±0.05% of the disintegrations. These data partly disagree significantly from measurements of other authors. Using the fluorescence yieldsω k (Cr)=0.279 andω k (Cu)=0.4425, deduced from other measurements, values ofL+M/K of electron capture to the excited state could be derived:L+M/K(Mn 54)=0.120±0.015 andL+M/K(Zn 65)=0.127±0.015. These ratios agree with the calculations ofBahcall. The half-lives of Mn 54 and Zn 65 have been determined to beT 1/2(Mn 54)=312±5d,T 1/2(Zn 65)=243±4d The energy of the Zn 65-γ-rays was measured with a Ge(Li)-counter:E γ=1115.5±0.5 keV. 相似文献
14.
M.F. Thomas J. Bland G.S. Case J.A. Hutchings O. Nikolov 《Hyperfine Interactions》2000,126(1-4):377-386
Magnetic anisotropy between in-plane and out of plane magnetic alignments is studied in a variety of multilayer systems using Mössbauer spectrosopy to observe the (Fe) magnetic orientation. The surface anisotropy in Fe/Au (1 1 1) multilayers is measured as K s = 0.9 × 10?3 Jm?2. In Fe/Ni multilayers the dependence of magnetic orientation on external field applied normal to the layers enables volume and interface anisotropies K v = (?5 ± 1) × 104 Jm?3 and K s = (?0.6 ± 0.4)× 10?3 Jm?2 to be evaluated. In similar applied field experiments coherent rotation of the magnetic Fe and NiFe layers in Fe/Cu/NiFe/Cu multilayers was observed for intervening Cu layer thickness x = 5 Å but independent rotation for x = 50 Å. Out of plane magnetic components are observed for DyFe2, YFe2 thin films and DyFe2/YFe2 multilayers. In fields of up to 0.25 T applied inplane only the moments of the YFe2 film showed significant rotation. 相似文献
15.
M. Büscher R. Eßer A. Franzen L. v. Horn D. Kopyto H. Ohm H. Seyfarth K. Sistemich H. Müller B. Prietzschk B. Rimarzig C. Schneider C. Schneidereit A. Akindinov M. Chumakov V. Demechin V. Ergakov A. Gerasimov V. Goryachev Y. Kiselev V. Kostromin A. A. Sibirtsev V. Sopov V. Tchernyshev V. Kruglov A. Petrus V. Koptev S. Mikirtychyants 《Zeitschrift für Physik A Hadrons and Nuclei》1996,355(1):93-100
The production ofK + andπ + mesons and protons inpBe collisions atT p=2.9 GeV has been studied at the ITEP proton synchrotron. Ejectiles with a momentum ofp=545 MeV/c were observed under an emission angle ?=17°. The detectors which have been developed for the identification of kaons out of a six orders of magnitude more intense background of pions and protons are described. A cross-section ratio d2σ K +/dΩdp: d2 σ p /dΩdp: d2σ p /dΩdp of (1±0.34):(85±1):(31±1) has been measured. Normalization with existing pion data yields an invariant differential cross sectionE·d3σ K +/d3 p=(3.1±1.2) mbGeV?2c3sr?1 and a total cross section of σtot(pBe)=(3.7±1.5) mb. These cross sections are compared with existing data and theoretical predictions. TheA dependence ofK + production in the few-GeV range is analyzed. 相似文献
16.
The study of the gas-phase infrared spectrum of C2H6 in the region of the perpendicular CH-stretching band, ν7, near 3000 cm?1 is extended for the ΔK = + 1 subbands as far as K = 20. The spectral resolution of ~0.030 cm?1 is increased to ~0.015 cm?1 by deconvolution. The earlier investigation of this band for KΔK = +9 to ?5, is repeated with greater accuracy, providing more reliable ground-state constants (cm?1): B0 = 0.663089 ± 24, D0J = (0.108 ± 4) × 10?5, D0JK = (0.50 ± 7) × 10?5. The molecular constants (cm?1) for the ν7 fundamental are B7 = 0.66310 ± 3, A7 = 2.682, ν0 = 2985.39, ζ7 = 0.128. A discussion of resonance effects in this band, in particular x-y-Coriolis and Fermi resonance, is given. 相似文献
17.
A.D. Martin T. Shimada R. Baldi T. Böhringer P.A. Dorsaz V. Hungerbühler M.N. Kienzle-Focacci M. Martin A. Mermoud C. Nef P. Siegrist 《Nuclear Physics B》1978,134(3):392-412
High statistics data for the reactions K±p → KS0π±p at 10 GeV/c are analysed. The K1(1?), K1(2+), and K1(3?) resonance parameters and production cross sections are calculated. The Kπ production amplitudes are determined as a function of t and the produced Kπ mass. Isoscalar natural-parity-exchange (NPE) is dominant. The t dependence of the K± NPE amplitudes have a cross-over at t = ?0.3 (GeV/c)2 for both K1(890) and K1(1420) production, being more pronounced for the K1(1420). Natural-parity-exchange interference effects are isolated. The NPE amplitudes are decomposed into pomeron-, f-, and ω-exchange contributions. S-wave Kπ production is found to be consistent with the Kπ partial-wave analyses of charge-exchange reactions. 相似文献
18.
Ts. Venkova T. Morek G. V. Martí H. Schnare A. Krämer-Flecken W. Gast A. Georgiev G. Hebbinghaus R. M. Lieder G. Sletten K. M. Spohr K. H. Maier W. Urban 《Zeitschrift für Physik A Hadrons and Nuclei》1993,344(4):417-423
Two new isomers have been observed in180Os. A high-K isomer withI, K ≧20 and a half-life ofT 1/2=12+4 ns have been established. It deexcites via two transitions into the 18+ level of the yrare band indicating an unusually smallK-hindrance factor. Evidence for an isomer withI, K>16 and a half-life ofT 1/2=41±10 ns was found. A half-life of 17±3 ns was measured for the previously known 7? state at 1862 keV. The decay scheme of the previously known 7? isomer at 1928 keV has been extended and a revised version is presented. 相似文献
19.
A. Visvanathan E. G. Funk J. W. Mihelich 《Zeitschrift für Physik A Hadrons and Nuclei》1974,271(4):339-343
TheK-internal conversion coefficients have been measured by the XPG technique for a number of low energyγ-ray transitions whose energies do not exceed theK-binding energies by more than 4 keV. Using Si(Li) detectors in singles and coincidence arrangements, the following results were obtained: 63.1 keV El in169Tm(αK=1.02±0.15), 72.0 keV E1 in187Re (0.75±0.05), 57.8 keV M1 in162Ho (11.42±0.67), 56.6 keV M1 in164Ho (12.04±0.70), and 67.1 keV M1 in174Lu(10.25±0.58). The experimental results are compared with the theoretical calculations which include transition energies down to 1 keV above threshold. 相似文献
20.
W. -D. Schmidt-Ott J. S. Hansen R. W. Fink 《Zeitschrift für Physik A Hadrons and Nuclei》1972,250(3):191-197
Accurate intensity measurements of the majorK x-ray groups have been performed with high resolution Ge(Li) detectors in singles and coincidence arrangements and with a high-purity Ge detector of the intrinsic type. Previously reportedK x-ray intensities forZ=96 are in error due to the presence of a 121.5 keV γ-ray in the decay of249Cf. The present results are as follows: forZ=81,K α2/K α1=0.589±0.008, \(K_{\beta _1^\prime } /K_{\alpha ^1 } = 0.344 \pm 0.008, K_{\beta _2^\prime } /K_{\alpha _1 } = 0.102 \pm 0.004\) , andK β/K α=0.281±0.006; forZ=92 \(K_{\alpha _2 } /K_{\alpha _1 } = 0.611 \pm 0.008,K_{\beta _1^\prime } /K_{\alpha _1 } = 0.365 \pm 0.008, K_{\beta _2^\prime } /K_{\alpha _1 } = 0.125 \pm 0.004\) , andK β/K α=0.300±0.006; forZ=94, \(K_{\alpha _2 } /K_{\alpha _1 } = 0.610 \pm 0.008, K_{\beta _1^\prime } /K_{\alpha _1 } = 0.369 \pm 0.010, K_{\beta _2^\prime } /K_{\alpha _1 } = 0.127 \pm 0.004\) , andK β/K α=0.308±0.008; and forZ=96, \(K_{\alpha _2 } /K_{\alpha _1 } = 0.627 \pm 0.008, K_{\beta _1^\prime } /K_{\alpha _1 } = 0.372 \pm 0.009, K_{\beta _2^\prime } /K_{\alpha _1 } = 0.133 \pm 0.005\) , andK β/K α=0.310±0.008. The error limits are the 2σ statistical errors to which a systematic error in the detector efficiencies has been added linearly. The present results are compared with recent theoretical calculations. 相似文献