The proton resonant properties in 18Ne, which determine the reaction rate of the key stellar 14O(α,p)17F reaction, have been studied by using a technique of proton resonant elastic scattering of 17F+p. A 4.22 MeV/nuc...The proton resonant properties in 18Ne, which determine the reaction rate of the key stellar 14O(α,p)17F reaction, have been studied by using a technique of proton resonant elastic scattering of 17F+p. A 4.22 MeV/nucleon 17F radioactive ion (RI) beam was produced via a projectile-fragmentation reaction, and separated by a Radioactive Ion Beam Line in Lanzhou (RIBLL). By bombarding a thick (CH2)n target, the energy spectra of the recoiled protons were measured by two ΔE-E silicon telescopes at the center-of-mass scattering angles of θc.m.≈175°±5°, θc.m.≈152°±8°, respectively. Several proton resonances in 18Ne were ob served clearly. A further R-matrix analysis of the experimental data is under way to determine the resonant parameters. The present work reports the preliminary results briefly.展开更多
A corrective factor (E,ρ)≤1) dependent on ion energy and mass density of material for energy loss has been introduced into Bethe-Bloch formula, so that the energy deposition process of fast ion penetrating through t...A corrective factor (E,ρ)≤1) dependent on ion energy and mass density of material for energy loss has been introduced into Bethe-Bloch formula, so that the energy deposition process of fast ion penetrating through the allotropic solid films are well discussed with the two-component assumption. An analysis expression of electronic stopping power for different phase structures has been derived from the contribution of "valence" and "core" electrons. The two thirds of inelastic scattering arisen from valence electron was revealed by comparing the theoretical calculation and experimental results on both random and oriented lattice site. The corrective factor representative to the role of inner electrons increases with the projectile energy but decreases with mass density of solids.展开更多
For a series of incoherent condensate atomic clouds with vortices （an orbital angular momentum） released from an optical lattice, the density-density correlation function of this freely expanding ultracold gases is ...For a series of incoherent condensate atomic clouds with vortices （an orbital angular momentum） released from an optical lattice, the density-density correlation function of this freely expanding ultracold gases is theoretically investigated. It is shown that the nonzero angular momentum of the atoms has an important effect on the fringe pattern of density-density correlation. Particularly, for a short expansion time, even the rotation direction of the atoms could have an observable effect on the fringe pattern. Observation of this specific fringe pattern would constitute experimental evidence for the presence of a vortex in an atomic condensate.展开更多
Analyzing powers and differential cross sections have been measured for elastic scattering of 22MeV polarized protons from 40Ca, 16O and 12C, and differential cross sections for inelastic scattering of 22 MeV protons ...Analyzing powers and differential cross sections have been measured for elastic scattering of 22MeV polarized protons from 40Ca, 16O and 12C, and differential cross sections for inelastic scattering of 22 MeV protons from 3- (3.736 MeV) and 5-(4.491 MeV) states of 40Ca have also been measured. The experimental data for polarized proton elastic scattering have been analyzed with a phenomenological optical potential parameters, the experimental data and theoretical values are in good agreement. In the theoretical frame of microscopic single scattering model, transition densities extracted from electron inelastic scattering and M3Y and Halderson’s effective interactions have been utilized to analyze the experimental data of 22 MeV proton inelastic scattering from 40Ca. Overall, it seems that Halderson’s effective interaction can better describe the experimental data than M3Y although the degree of agreement between experimental and theoretical values needs to he improved.展开更多
Recently we have constructed two facilities for generating photon beams in the MeV and sub-MeV energy regions by means of the Compton backscattering with a laser and an electron beam at SPring-8 and at Kansai Photon S...Recently we have constructed two facilities for generating photon beams in the MeV and sub-MeV energy regions by means of the Compton backscattering with a laser and an electron beam at SPring-8 and at Kansai Photon Science Institute of Japan Atomic Energy Agency(KPSI-JAEA). The MeV-photon source at SPring-8 consists of a continuous-wave optically-pumped far infrared laser with a wavelength of 118.8 μm and an 8 GeV stored electron beam. Present MeV-photon flux is estimated to be 1.3×103 photons/s. On the other hand,the sub-MeV-photon source at KPSI-JAEA consists of a pulse Nd∶YAG laser with a wavelength of 1 064 nm and a 150 MeV electron beam accelerated by microtron. In the first trial of the photon production in this source,backscattered photon flux is estimated to be 20 photons/pulse. Both the Compton backscattered photon sources have possibilities to be used for new tools in various fields such as nuclear physics,materials science,and astronomy.展开更多
基金supported by the "100 Persons Project" (Grant No. BR091104)the Knowledge Innovation Program of the Chinese Academy of Sciences (Grant NO. KJCX2-YW-N32)+1 种基金the National Natural Science Foundation of China (Grant Nos. 10975163 and 11021504) the Major State Basic Research Development Program of China (Grant No. 2007CB815000)
文摘The proton resonant properties in 18Ne, which determine the reaction rate of the key stellar 14O(α,p)17F reaction, have been studied by using a technique of proton resonant elastic scattering of 17F+p. A 4.22 MeV/nucleon 17F radioactive ion (RI) beam was produced via a projectile-fragmentation reaction, and separated by a Radioactive Ion Beam Line in Lanzhou (RIBLL). By bombarding a thick (CH2)n target, the energy spectra of the recoiled protons were measured by two ΔE-E silicon telescopes at the center-of-mass scattering angles of θc.m.≈175°±5°, θc.m.≈152°±8°, respectively. Several proton resonances in 18Ne were ob served clearly. A further R-matrix analysis of the experimental data is under way to determine the resonant parameters. The present work reports the preliminary results briefly.
文摘A corrective factor (E,ρ)≤1) dependent on ion energy and mass density of material for energy loss has been introduced into Bethe-Bloch formula, so that the energy deposition process of fast ion penetrating through the allotropic solid films are well discussed with the two-component assumption. An analysis expression of electronic stopping power for different phase structures has been derived from the contribution of "valence" and "core" electrons. The two thirds of inelastic scattering arisen from valence electron was revealed by comparing the theoretical calculation and experimental results on both random and oriented lattice site. The corrective factor representative to the role of inner electrons increases with the projectile energy but decreases with mass density of solids.
基金Supported by the Natural Science Foundation of Zhejiang Province under Grant Y6090620.
文摘For a series of incoherent condensate atomic clouds with vortices （an orbital angular momentum） released from an optical lattice, the density-density correlation function of this freely expanding ultracold gases is theoretically investigated. It is shown that the nonzero angular momentum of the atoms has an important effect on the fringe pattern of density-density correlation. Particularly, for a short expansion time, even the rotation direction of the atoms could have an observable effect on the fringe pattern. Observation of this specific fringe pattern would constitute experimental evidence for the presence of a vortex in an atomic condensate.
基金the National Natural Science Foundation of China under Grant (19575032)
文摘Analyzing powers and differential cross sections have been measured for elastic scattering of 22MeV polarized protons from 40Ca, 16O and 12C, and differential cross sections for inelastic scattering of 22 MeV protons from 3- (3.736 MeV) and 5-(4.491 MeV) states of 40Ca have also been measured. The experimental data for polarized proton elastic scattering have been analyzed with a phenomenological optical potential parameters, the experimental data and theoretical values are in good agreement. In the theoretical frame of microscopic single scattering model, transition densities extracted from electron inelastic scattering and M3Y and Halderson’s effective interactions have been utilized to analyze the experimental data of 22 MeV proton inelastic scattering from 40Ca. Overall, it seems that Halderson’s effective interaction can better describe the experimental data than M3Y although the degree of agreement between experimental and theoretical values needs to he improved.
基金Japan Societyfor Promotion of Science under Grant-and Aid for Scientific Research(14205018)Ministry of Educa-tion,Science,Sports and Culture of Japan under Grant-and-Aid for Specially Promoted Research (15002013)
文摘Recently we have constructed two facilities for generating photon beams in the MeV and sub-MeV energy regions by means of the Compton backscattering with a laser and an electron beam at SPring-8 and at Kansai Photon Science Institute of Japan Atomic Energy Agency(KPSI-JAEA). The MeV-photon source at SPring-8 consists of a continuous-wave optically-pumped far infrared laser with a wavelength of 118.8 μm and an 8 GeV stored electron beam. Present MeV-photon flux is estimated to be 1.3×103 photons/s. On the other hand,the sub-MeV-photon source at KPSI-JAEA consists of a pulse Nd∶YAG laser with a wavelength of 1 064 nm and a 150 MeV electron beam accelerated by microtron. In the first trial of the photon production in this source,backscattered photon flux is estimated to be 20 photons/pulse. Both the Compton backscattered photon sources have possibilities to be used for new tools in various fields such as nuclear physics,materials science,and astronomy.
