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The γ-rays and protons from an Ed = 20 keV deuteron beam incident on a D-Ti target were measured. A branching ratio of the 2H(d,γ)^4He reaction versus the ^2H(d,p)^3H reaction of Гγ/Гp = (1.061 0.34) x 10.7 has been obtained, and the astrophysical S factor of the ^2H(d,γ)He reaction at the center of mass energy Ecm ≈ 7 keV of (6.0±2.4) ×10^6 keV.b was deduced. 相似文献
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The spatial distributions of the electron density and the mean electron energy of argon radio frequency (rf) glow discharge plasma in a plasma-enhanced chemical vapour deposition (PECVD) system have been investigated using an established movable Langmuir probe. The results indicate that in the axial direction the electron density tends to peak at midway between the two electrodes while the axial variation trend of mean electron energy is different from that of the electron density, the mean electron energy is high near the electrodes. And the mean electron energy near the cathode is much higher than that near the anode. This article focuses on the radial distribution of electron density and mean electron energy. A proposed theoretical model distribution agrees well with the experimental one: the electron density and the mean electron energy both increase from the centre of the glow to the edge of electrodes. This is useful for better understanding the discharge mechanism and searching for a better deposition condition to improve thin film quality. 相似文献
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The effect of tensor interaction due to gluon and Goldstone boson exchange on the dibaryon mass and decay width has been studied in the framework of the quark delocalization and colour screening model. The effective S-D wave transition interactions induced by gluon and Goldstone boson exchanges decrease quickly with the increasing channel strangeness, and there is no six-quark state in the light flavour world, which can become a bound one by the help of these tensor interactions, except for the deuteron. The K and η meson exchange effect has been shown to be negligible after a short-range truncation in this model approach. The partial D-wave decay widths, from the NΩ state to the AΞ final states of spins 0 and 1, are 20.7 keV and 63.1 keV respectively. This is a very narrow dibaryon resonance, that might be detected in the relativistic heavy ion reaction by the existing RHIC detectors through the reconstruction of the AΞ vertex mass and by the future COMPAS detector at CERNand the FAIR project in Germany. 相似文献
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Measurement of D(d,p) T Reaction Cross Sections in Sm Metal in Low Energy Region (10≤Ed≤20keV) 下载免费PDF全文
WANG Tie-Shan YANG Zhen H. Yunemura A. Nakagawa LV Hui-Yi CHEN Jian-Yong LIU Sheng-Jin J. Kasagi 《中国物理快报》2007,24(11):3103-3106
To study the screening effect of nuclear reactions in metallic environments, the thick target yields, the cross sections and the experimental S(E) factors of the D(d,p)T reaction have been measured on deuterons implanted in Sm metal at 133.2K for beam energies ranging from 10 to 20keV. The thick target yields of protons emitted in the D(d,p) T reaction are measured and compared with those data extrapolated from cross sections and stopping power data at higher energies. The screening potential in Sm metal at 133.2K is deduced tobe 520±56eV. As compared with the value achieved in the gas target, thecalculated screening potential values are much larger. This screening potential cannot be simply interpreted only by the electron screening. Energy dependences of the cross section σ(E) and the experimental S(E) factor for D(d,p)T reaction in Sm metal at 133.2K are obtained, respectively. 相似文献
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The angular distribution of the ^2H(^8Li, ^9Be)n (ground state) reaction, important to primordial nucleosynthesis in the inhomogeneous model, has been measured at E = 8.1 MeV using a secondary ^8Li beam. Cross section of this reaction was determined to be 9.0 4±3.4 mb. According to the cross section, the astrophysical S-factor was calculated to be 272 4±103 keV b. It is shown that ^2H(8^Li, ^9Be)n (ground state) reaction is important for creating 9Be, but less important for destroying aLl in primordial nucleosynthesis. 相似文献
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Geant4 tools were used to model the single event upset (SEU) of static random access memory cells induced by heavy ion irradiation. Simulated results obtained in two different regions of incident ion energies have been compared in order to observe the SEU occurrence by energetic ions and their effects on the radial ionization profile of deposited energy density. The disagreement of SEU cross sections of device response and radial distribution of deposited energy density have been observed in both low energy and high energy regions with equal linear energy transfer (LET) which correspond to the both sides of the Bragg peak. In the low energy region, SEUs induced by heavy ions are more dependent upon the incident ion species and radial distribution of deposited energy density, as compared with the high energy region. In addition, the velocity effect of the incident ion in silicon in the high energy region provides valuable feedback for gaining insight into the occurrence of SEU. 相似文献
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Heavy ions and pulsed lasers are important means to simulate the ionization damage effects on semiconductor materials. The analytic solution of high-energy heavy ion energy loss in silicon has been obtained using the Bethe-Bloch formula and the Kobetich-Katz theory, and some ionization damage parameters of Fe ions in silicon, such as the track structure and ionized charge density distribution, have been calculated and analyzed according to the theoretical calculation results. Using the Gaussian function and Beer's law, the parameters of the track structure and charge density distribution induced by a pulsed laser in silicon have also been calculated and compared with those of Fe ions in silicon, which provides a theoretical basis for ionization damage effect modeling. 相似文献
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王佳叶沿林 江栋兴张高龙庞丹阳 李智焕郑涛李湘庆 王全进胡青元 吴翠娥A.Ozawa Y.Yamaguchi R.Kanungo D.Fang I.Tanihata 《中国物理快报》2005,22(6):1370-1373
The breakup reaction cross sections were measured for the reaction of^6He at 25 MeV/nucleon from ^9Be target with intensity of 10^5 pps. By fitting the energy spectra of breakup α particles with Gaussian functions, the angular distribution of differential cross sections in the laboratory system has been extracted and compared with the Serber model calculations. The good agreement between the calculation and the experimental data favours a dominant configuration of the ^4He core plus valence neutrons for the structure of^6He. 相似文献
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Experimental Evidence of the Rapidly Increasing Neutron Yields in Proton—Induced Reaction on Heavy Target Across 0.6—1 GeV 下载免费PDF全文
The independent yield distribution of the Hg isotopes,measured for the reaction of 600MeV ^18O projectile with a ^nat.Pb target,is converted to 18O 208Phb system and is compared with an Hg-isotope distribution from the spallation reaction of 1A GeV^208Pb on proton.The comparison shows the differences between the two distributions on the production cross sections,isotope-distribution widths as well as their shapes.A great increase of the neutron-deficient Hg isotope yield with increase of bombarding energies of protons from 600MeV to 1GeV is derived.This fact results in an experimental evidence for rapid increasing neutron yields with rising proton bombarding energy from 0.6GeV to 1 GeV. 相似文献
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We adopt the Nambu–Jona-Lasinio(NJL) model to study the crust-core transition properties in neutron stars(NSs). For a given momentum cutoff and symmetry energy of saturation density in the NJL model, decreasing the slope of the symmetry energy gives rise to an increase in the crust-core transition density and transition pressure.Given the slope of the symmetry energy at saturation density, the transition density and corresponding transition pressure increase with increasing symmetry energy. The increasing trend between the fraction of the crustal moment of inertia and the slope of symmetry energy at saturation density indicates that a relatively large momentum cutoff of the NJL model is preferred. For a momentum cutoff of 500 Me V, the fraction of the crustal moment of inertia clearly increases with the slope of symmetry energy at saturation density. Thus, at the required fraction(7%) of the crustal moment of inertia, the NJL model with momentum cutoff of 500 Me V and a large slope of the symmetry energy of saturation density can give the upper limit of the mass of the Vela pulsar to be above 1.40 M_⊙. 相似文献
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The investigation was made of the dependence of the intensity of Tl, Ga, Mo, Mg, Mn, Sn, Bi, Ni, Zn, Pt and Au spectral lines and the plasma parameters (temperature T, electron concentration ne, degree of 6 ionnization α) from concentration of lithium additive. 相似文献
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Let G be one of the local gauge groups C(X, U(n)),C
(X, U(n)), C(X, SU(n)) or C
(X, SU(n)) where X is a compact Riemannian manifold. We observe that G has a nontrivial group topology, coarser than its natural topology, w.r.t. which it is amenable, viz. the relative weak topology of C(X, M(n)). This topology seems more useful than other known amenable topologies for G. We construct a simple fermionic model containing an action of G, continuous w.r.t. this amenable topology. 相似文献
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Denis de Carvalho Braga 《Physics letters. A》2010,374(42):4316-4320
In this note we present an analytical study of the stability of the equilibria of the Rikitake system. We prove that the two non-hyperbolic equilibria of the Rikitake system are unstable for all positive values of the parameters. 相似文献
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