Search results for "nuclear fusion"
showing 10 items of 437 documents
High spin shell model excitations in149Gd
1981
The high spin level structure of the three-neutron nucleus149Gd has been investigated by in-beamγ-ray and electron spectroscopy with (α, xn) reactions. The observed levels are characterized as members of the shell model multipletsνf 7 2/3 ,νh 9/2 f 7 2/2 ,νf 7 2/3 ×3−,νh 9/2 f 7 2/2 ×3−, and tentativelyνf 7 2/3 ×(3−)2. The energies of theν f 7 2/3 states agree only moderately with those calculated using empirical two-nucleon interactions taken from148Gd, which indicates the importance of long range contributions already atN=85.
Zur Sekund�relektronenemission durch Argonionen und Argonatome im Energiebereich von 1 bis 20 keV
1966
Be-, CuBe-, Cu- and Al-targets are bombarded by single A+ and A0 in the energy range from 1 to 20 keV. The secondary electrons accelerated by 20 keV are counted by a proportional counter backed by a multichannel analyser. The probability distributionPn of emission ofn=0,1, 2, 3, ... secondary electrons can be found from the pulse height distribution. WhenPn is known the yield for A+ and A0 can be calculated. The counting of neutrals in the energy range investigated is discussed.
The 235 ns 9+ isomer in 63 148 Eu85
1981
From (p, xn) in-beamγ-ray and electron measurements aT1/2=235(14) ns isomer at 720 keV was identified in63148Eu85 and the levels populated in its decay have been characterized. The results determineIπ=9+ for the isomeric state, and we assign it as the (πh11/2j0−2ν f72/3)9+ shell model state, analogous to the configuration of the 235 μs isomer in63146Eu83.
Medium-spin levels in the N=83 nucleus147Gd
1983
Levels of theN=83 nucleus147Gd have been investigated by methods of in-beamγ-ray and conversion electron spectroscopy using the147Sm(3He, 3n) and144Sm(α, n) reactions. Sixteen new low- and medium-spin levels have been observed in147Gd. We have located six members of thevf7/2×3− particle-octupole septuplet and several neutron single-particle states in147Gd. The levels of147Gd are discussed on the basis of the spherical shell model.
The decay of 31 sec98Zr, 2.9 sec98Nb and 51 min98Nb
1976
TheΒ- andγ-radiations of98Zr and98m, g Nb have been investigated employing scintillation and semiconductor spectrometers and coincidence techniques. Sources of98Nb were produced by the98Mo(n, p)98Nb reaction, sources of98Zr by fission of235U with thermal neutrons applying chemical separations. For98Zr, a half-life of 30.7±0.4 sec and aQ β-value of 2.3±0.2 MeV were obtained, for the98Nb isomers, half-lives of 2.86±0.06 sec and 51.3±0.4 min, andQ β-values of 4.8±0.2 MeV and 4.5±0.2 MeV, respectively. Noγ-rays were observed in the decay of98Zr. The decay of 2.9 sec98Nb was found to involve 11γ-ray transitions. In the decay of 51 min98Nb, 54γ-transitions were detected. Spin and parity of 1+ and…
The decay of 8.7 min237Pa
1974
The beta and gamma radiations of237Pa have been investigated employing semiconductor and scintillation spectrometers and coincidence techniques. Sources of237Pa were obtained after bombardments of238U with bremsstrahlung and 14-MeV neutrons and subsequent chemical separation. From the total of 18γ-rays following the decay of 8.7±0.2 min237Pa 17 transitions, representing 99.9% of theγ-ray intensity, could be placed in a level scheme of237U. AQ β- value of 2.25±0.1 MeV has been determined.
Der Zerfall des93Sr
1972
The nucleide93Sr was isolated by chemical separation methods after thermal neutron induced fission of235U, and its decay properties were investigated employing scintillation and semiconductor spectrometers and coincidence techniques. A half-life of 7.43±0.03 min and aQβ-value of 4.3±0.2 MeV were found. Out of 74 gamma-rays, 55 transitions, representing 97% of the observed gamma-ray intensity, could be placed in a decay scheme comprising 22 excited states of93Y.
Der Zerfall des 2,4-sec100Nb
1972
The nuclide100Nb was produced by irradiation of enriched100Mo targets with 14 MeV-neutrons, and its decay properties were investigated employing scintillation and semiconductor spectrometers and coincidence techniques. A half-life of 2.4±0.3 sec and aQ β-value of 5.8±0.2 MeV were found. From 27 gamma-rays, 20 transitions, representing 95% of the observed gamma-ray intensity, could be placed in a decay scheme comprising 10 excited states of100Mo.
Decay of the 4.2-min152Pm into levels of152Sm
1975
After bombardments of enriched152Sm with 14-MeV neutrons, three isomers of125Pm reaction, have been observed with half-lives of 4.2±0.2 min, 7.5±0.2 min and 15.0±1.0 min. Sources of pure 4.2-min152Pm were obtained by separating the promethium from its parent 11-min152Nd produced by thermal-neutron induced fission of235U. The beta and gamma radiations of the 4.2-min152Pm have been investigated using semiconductor and scintillation spectrometers. Most of theγ-ray transitions could be placed in a level scheme for 152Sm. Especially interesting is a level at 1083 keV for which the assignmentI π=0+ is proposed. In a 4πβγ experiment, the ground state feeding of152Sm in theβ −-decay of the 4.2-min1…
A sum-rule approach to nuclear ground state correlations
1985
By combining the sum-rule approximation to nuclear giant resonances with a generator-coordinate description of the collective ground-state we obtain a simple estimate of the collective ground-state correlations. We investigate the approach for a variety of nuclei and forces. The correlation effects are small but not negligible in view of the precision achieved in modern Skyrme-Hartree-Fock calculations.