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31.
A search for the12C decay of114Ba produced in the58Ni(58Ni,2n) reaction was performed by using polycarbonate track detectors. Assuming the total half-life of114Ba to be 0.1 s, the lower limit T c ≥103 s for the partial12C-decay half-life was established.  相似文献   
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33.
The setting of the experiments is described and the results obtained on the synthesis of the heaviest nuclides in reactions induced by 48Ca projectiles are presented. The decay properties of the new nuclei confirm the theoretical predictions about the new nuclear shells and the “islands of stability” of superheavy elements. Briefly, also the results of the first experiments aimed to study the atomic and chemical properties of element 112 are reported.  相似文献   
34.
A resonance state situated at 1.8±0.1 and, most likely, another state positioned at 2.7±0.1 MeV above the t+n+n decay threshold were observed in the missing mass energy spectrum of the 5H nucleus produced in the reaction 3H(t,p)5H. The peak located close to $E_{^5 H} = 1.8$ MeV also was seen in the 5H spectrum obtained from the energy distributions of 3H nuclei emitted in the reaction 2H(6He,5H)3He. The width (Γobs ≤ 0.5 MeV) obtained for the two 5H resonance states is surprisingly small. A state of 4H with E res = 3.3 MeV and γ2 = 2.3 MeV was obtained in the reaction 2H(t,p)4H from the proton spectrum.  相似文献   
35.
A new experiment devoted to the fission of 252Cf is described. It continued a series of our experiments based on correlation measurements of γ rays emitted by fission fragment pairs. The measurements of γ-γ and γ-γ-γ coincidences were done at Gammasphere with closed 252Cf sources. The open source was used for the first time in the last experiment. Fission fragment detectors were arranged in the center hole of Gammasphere. Correlations between fission fragment masses, total kinetic energy, and γ rays were observed. The first, preliminary results of data analysis are discussed. The text was submitted by the authors in English.  相似文献   
36.
We calculate the moments of heavy quark-parton distribution in heavy flavored (c, b) mesons with variousJ P by means of QCD sum rule approach. The results demonstrate that this method allows to distinguish between the structure functions of hadrons with the same quark content and different spin-parity. In particular the leading effect of heavy quark is less in the case ofP-wave mesons (0+, 1+). This prediction may be tested in the fragmentation of heavy quark into mesons with variousJ P.  相似文献   
37.
The mass-separator MASHA built to identify Super Heavy Elements by their mass-to-charge ratios is described. The results of the off- and on-line measurements of its separation efficiency are presented. In the former case four calibrated leaks of noble gases were used. In the latter the efficiency was measured via 284 MeV $^{40}$ Ar beam and with using the hot catcher. The ECR ion source was used in both cases. The $\alpha $ -radioactive isotopes of mercury produced in the complete fusion reaction $^{40}$ Ar+ $^{144}$ Sm $\rightarrow ^{184-xn}$ Hg+xn were detected at the mass-separator focal plane. The half-lives and the separation efficiency for the short-lived mercury isotopes were measured. Potentialities of the MEDIPIX detector system have been demonstrated for future use at the mass-separator MASHA.  相似文献   
38.
Nuclear dissipation in capture reactions is investigated using backtracing, a new analysis protocol. Combining analysis procedure with dynamical models, the difficult and long-standing problem of competition and mixing between quasifission and fusion-fission is solved for the first time. The nature of the relevant dissipation is determined as one-body dissipation. At low excitation energy where shell effects are strongly effective, the shape of the mass distribution could be a powerful check of the nature and the magnitude of the dissipation.  相似文献   
39.
Within the past twelve years, the recoil separator VASSILISSA has been used for the investigations of evaporation residues produced in heavy-ion-induced complete fusion reactions. In the course of the experimental work, fourteen new isotopes have been identified by the parent-daughter correlations in the region of elements with 92≤Z≤94. The study of the decay properties and formation cross sections of the isotopes of elements 110, 112, and 114 was performed using high-intensity 48Ca beams and 232Th, 238U, and 242Pu targets. At the beam energies corresponding to the calculated cross-section maxima of the 3n evaporation channels, the isotopes 277110, 283112, and 287114 were produced and identified. For further experiments aimed at the synthesis of the superheavy element isotopes (Z≥110) with the use of intensive 48Ca extracted beams, improvements in the ion optical system of the separator and the focal plane detector system have been made.  相似文献   
40.
The spectrum of 10He was studied by means of the 3H(8He, p)10He reaction at a laboratory energy of 25 MeV/A and small center-of-mass angles. Missing mass spectrum of 10He was derived from the obtained p-8He coincidence. A resolution of 0.7 MeV was achieved in this spectrum for the measured 10He energy. Most likely, a well isolated group of 10 events detected between 2 and 5 MeV and showing a maximum at about 3 MeV in the spectrum of the present work exhibits the 10He g.s. resonance.  相似文献   
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