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[Abridged] Investigations of neutron(n)-capture element nucleosynthesis and chemical evolution have largely been based on stellar spectroscopy. However, the recent detection of these elements in several planetary nebulae (PNe) indicates…

The scintillation efficiency (quenching factor) of fluorine and calcium nuclei recoiling in a CaF-2(Eu) crystal was measured in an energy region relevant to dark matter searches. The recoiling nuclei were obtained via the 19-F(n,n') and…

核实验 · 物理学 2009-11-07 R. Hazama , S. Ajimura , H. Hayakawa , K. Matsuoka , H. Miyawaki , K. Morikubo , N. Suzuki , T. Kishimoto

The excitation functions for (n,p) reactions from reaction threshold to 24 MeV on some important iron (Fe) group target elements for astrophysical (n, p) reactions such as Si, Ca, Sc, Ti, Cr, Fe, Co and Ni were calculated using TALYS-1.0…

核理论 · 物理学 2013-03-18 Tarik Siddik

The early stage of the chromium precipitation in copper was analyzed at the atomic scale by Atom Probe Tomography (APT). Quantitative data about the precipitate size, 3D shape, density, composition and volume fraction were obtained in a…

材料科学 · 物理学 2012-07-17 Abdelahad Chbihi , Xavier Sauvage , Didier Blavette

Excitation functions were measured for the $^{55}$Mn(n,2n)$^{54}$Mn, $^{55}$Mn(n,$\alpha$)$^{52}$V, $^{63}$Cu(n,$\alpha$)$^{60}$Co, $^{65}$Cu(n,2n)$^{64}$Cu, and $^{65}$Cu(n,p)$^{65}$Ni reactions from 13.47 to 14.83 MeV. The experimental…

We show that for the active-sterile flavor mixing parameters suggested by the reactor neutrino anomaly, substantial \\nu_e-\\nu_s and \bar \\nu_e-\bar \\nu_s conversion occurs in regions with electron fraction of \approx 1/3 near the core…

高能天体物理现象 · 物理学 2014-03-28 Meng-Ru Wu , Tobias Fischer , Lutz Huther , Gabriel Martínez-Pinedo , Yong-Zhong Qian

High resolution spectra obtained from the Subaru Telescope High Dispersion Spectrograph have been used to update the stellar atmospheric parameters and metallicity of the star HD 209621. We have derived a metallicity of [Fe/H] = -1.93 for…

太阳与恒星天体物理 · 物理学 2015-05-18 Aruna Goswami , Wako Aoki

Chemical abundances of 26 metal-poor dwarfs and giants are determined from high-resolution and high signal-to-noise ratio spectra obtained with Subaru/HDS. The sample is selected so that most of the objects have outer-halo kinematics.…

星系天体物理 · 物理学 2009-11-18 Lan Zhang , Miho Ishigaki , Wako Aoki , Gang Zhao , Masashi Chiba

Shell model calculations for Ni, Cu and Zn isotopes by modifying $fpg$ interaction due to Sorlin {\it et. al.,} [Phys. Rev. Lett. 88, 092501 (2002)] have been reported. In the present work 28 two body matrix elements of the earlier…

核理论 · 物理学 2012-04-24 P. C. Srivastava

The ground state neutron spectroscopic factors for 80 nuclei ranging in Z from 3 to 24 have been extracted by analyzing the past measurements of the angular distributions from (d,p) and (p,d) reactions. We demonstrate an approach that…

核实验 · 物理学 2008-11-26 M. B. Tsang , Jenny Lee , W. G. Lynch

All existing "positive" results on two neutrino double beta decay in different nuclei were analyzed. Using the procedure recommended by the Particle Data Group, weighted average values for half-lives of $^{48}$Ca, $^{76}$Ge, $^{82}$Se,…

核实验 · 物理学 2010-04-06 A. S. Barabash

A method is proposed to use of the mixture of Uran oxide and non-active matrix (e.g., NaCl) and also potassium and lanthanum for determining Ge-detector efficiencies. The preparations containing of known amouts of the U or K, or La were…

核实验 · 物理学 2012-04-02 E. G. Tertyshnik , I. E. Epifanova

For validation and development of codes and for modeling isotope production in high power accelerators and APT Materials studies, we have produced experimental, calculated, and evaluated activation libraries for interaction of nucleons with…

核理论 · 物理学 2007-05-23 S. G. Mashnik , A. J. Sierk , K. A. Van Riper , W. B. Wilson

Previous work on the abundances of C, O, Na, Mg, Si, Ca, Ti, Cr, Mn, Fe, Ni, Cu, and Zn in low-alpha (accreted) and high-alpha (in situ born) halo stars is extended to include the abundances of Sc, V, and Co, enabling us to study the…

星系天体物理 · 物理学 2023-12-14 P. E. Nissen , A. M. Amarsi , Á. Skúladóttir , W. J. Schuster

The quest for the origin of the chemical elements, which we find in our body, in our planet (Earth), in our star (Sun), or in our galaxy (Milky Way) could only be resolved with a thorough understanding of the nuclear physics properties of…

核实验 · 物理学 2018-03-26 René Reifarth , David Brown , Saed Dababneh , Yuri A. Litvinov , Shea M. Mosby

Neutrons from ($\alpha$,n) reactions through thorium and uranium decays are important sources of background for direct dark matter detection. The neutron yields and energy spectra from a range of materials that are used to build dark matter…

核实验 · 物理学 2009-08-05 D. -M. Mei , C. Zhang , A. Hime

Palladium (Pd) and silver (Ag) are the key elements for probing the weak component in the rapid neutron-capture process (r-process) of stellar nucleosynthesis. We performed a detailed analysis of the high-resolution and high signal-to-noise…

太阳与恒星天体物理 · 物理学 2015-06-24 Xiaoshu Wu , Liang Wang , Jianrong Shi , Gang Zhao , Frank Grupp

Based on high-resolution (R=60000) spectra taken with the NES spectrograph (the 6-m BTA telescope, the Special Astrophysical Observatory of the Russian Academy of Science), we have determined the abundances of 26 elements, from lithium to…

太阳与恒星天体物理 · 物理学 2015-09-28 Yu. V. Pakhomov

We determine abundances or upper limits for all of the 55 stable elements from copper to uranium for the A1 Vm star Sirius. The purpose of the study is to assemble the most complete picture of elemental abundances with the hope of revealing…

太阳与恒星天体物理 · 物理学 2016-08-17 Charles R. Cowley , Thomas R. Ayres , Fiorella Castelli , Austin F. Gulliver , Richard Monier , Glenn Wahlgren

We report the results of a coherent study of three chemically anomalous metal-poor ([Fe/H] ~ -2) stars. These objects exhibit unusually low abundances of Mg, Si, Ca (alpha-elements) and Sr, Y, and Ba (neutron-capture elements). Our analyses…