Photoneutron reactions in the range of giant dipole resonance

The well-known significant systematic disagreements between data on partial photoneutron reaction cross sections obtained in experiments using quasimonoenergetic annihilation photons and bremsstrahlung were investigated using objective physical criteria of data reliability. It was shown that many data are not reliable because of significant systematic uncertainties of the photoneutron multiplicity sorting methods used. The experimental–theoretical method for evaluation of reliable partial reaction cross sections was proposed and many new data were obtained.     

Neutrino-nucleus reactions in terrestrial experiments and astrophysics

We focus on the role and importance of neutrino-nucleus interactions to neutrino detection by terrestrial detector-nuclei and to various processes as well as scattering effects occurring inside the matter of stars (supernova, etc.) that generate the astrophysical neutrino energy spectra. We specifically concentrate on the parameterizations of the supernova neutrino energy distributions and examine the use of the low-energy β-beam spectra, originating from the boosted radioactive nuclei ⁶He and ¹⁸Ne, for such purposes.     

Fast neutron capture reactions in nuclear astrophysics

The cross sections of the neutron capture reaction on light nuclei, protons,¹²C and¹⁶O, were measured at astrophysically relevant energies between 10 and 300 keV. They are not only important for estimating yields of elements in the primordial nucleosynthesis, stellar nucleosynthesis of s-, r-, and p-processes, but also to study the role of meson exchange currents, the nuclear structure and the reaction mechanism. In the measurement, we used a prompt γ-ray detection method, combined with a pulsed neutron beam, and a recently developed Monte-Carlo code, TIME-MULTI, to correct for neutron multiple-scattering effects in a sample.     

Measurements of stellar and explosive nuclear astrophysics reactions

This paper described the nuclear astrophysical studies using the unstable ion beam facility GIRAFFE in CIAE, by indirect measurements. We measured the angular distributions for some single proton or neutron transfer reactions, such as ⁷Be(d,n)⁸B, ¹¹C(d,n)¹²N, ⁸Li(d,p)⁹Li and ¹³N(d,n)¹⁴O in inverse kinematics, and derived the astrophysical S-factors or reaction rates of ⁷Be(p,γ)⁸B, ¹¹C(p,γ)¹²N, ⁸Li(n,γ)⁹Li, ¹³N(p,γ)¹⁴O by asymptotic normalization coefficient, spectroscopic factor, and R-matrix approach at astrophysically relevant energies. Some most recent progress of nuclear astrophyiscal work in CIAE are also summarized.     

Gamma-ray astrophysics

Because of the very nature of the production processes. γ-ray astrophysics provides an excellent new opportunity to gain insight into the nature of the Universe. Gamma-ray astronomy permits a very direct study of the largest transfers of energy occurring in astrophysical processes, including rapid expansion processes explosions, high-energy particle acceleration, gravitational accretion onto superdense objects, the fundamental process of the building of the elements through nucleosynthesis, and even possibly particle-antiparticle annihilation.This review article give a summary of the current status and physical interpretation of γ-ray astronomy. The subject matter is divided into five topics solar observations, solar system bodies, stellar objects, the Galaxy, and other galaxies and cosmology. Since the whole of γ-ray astrophysics is too large a subject to be treated in depth in an article of this size, two topics have been selected from the several possible ones to be described more fully. These are remote γ-ray and X-ray sensing of planetary surfaces and diffuse galactic γ-radiation.     

Modulation instabilities in astrophysics

In this paper we consider various manifestations of modulational instabilities (MI) in astrophysical systems. Apart from the last section where we consider MI in a gravitating system, our main concern is with plasma MI and especially their importance for phenomena on the Sun, in the neighbourhood of the Earth, and near pulsars.     

Nuclear astrophysics

The International Year of Astronomy 2009 (IYA2009) was declared by the 62nd General Assembly of the United Nations and was also endorsed by UNESCO. Investigations in the realms of particle and nuclear physicsmake a large contribution in the development of our ideas of the properties of the Universe. The present article discusses some problems of the evolution of the Universe, nucleosyntheses, and cosmochronology from the point of view of nuclear and particle physics. Processes occurring in the Universe are compared with the mechanisms of the production and decay of nuclei, as well as with the mechanisms of their interaction at high energies. Examples that demonstrate the potential of nuclearphysics methods for studying cosmic objects and the properties of the Universe are given. The results that come from investigations into nuclear reactions induced by beams of radioactive nuclei and which make it possible to take a fresh look at the nucleosynthesis scenario in the range at light nuclei are presented.     

Exotic nuclei in astrophysics

Recently the academic community has marked several anniversaries connected with discoveries that played a significant role in the development of astrophysical investigations. The year 2009 was proclaimed by the United Nations the International Year of Astronomy. This was associated with the 400th anniversary of Galileo Galilei??s discovery of the optical telescope, which marked the beginning of regular research in the field of astronomy. An important contribution to not only the development of physics of the microcosm, but also to the understanding of processes occurring in the Universe, was the discovery of the atomic nucleus made by E. Rutherford 100 years ago. Since then the investigations in the fields of physics of particles and atomic nuclei have helped to understand many processes in the microcosm. Exactly 80 years ago, K. Yanski used a radio-telescope in order to receive the radiation from cosmic objects for the first time, and at the present time this research area of physics is the most efficient method for studying the properties of the Universe. Finally, the April 12, 1961 (50 years ago) launching of the first sputnik into space with a human being onboard, the Russian cosmonaut Yuri Gagarin, marked the beginning of exploration of the Universe with the direct participation of man. All these achievements considerably extended our ideas about the Universe. This work is an attempt to present some problems on the evolution of the Universe: the nucleosynthesis and cosmochronology from the standpoint of physics of particles and nuclei, in particular with the use of the latest results, obtained by means of radioactive nuclear beams. The comparison is made between the processes taking place in the Universe and the mechanisms of formation and decay of nuclei, as well as of their interaction at different energies. Examples are given to show the capabilities of nuclear-physics methods for studying cosmic objects and properties of the Universe. The results of investigations in nuclear reactions, induced by radioactive nuclear beams, make it possible to analyze the nucleosynthesis scenario in the region of light elements in a new manner.     

Magnetohydrodynamic kinks in astrophysics

Three-dimensional magnetic kinks in nonresistive plasmas may be created and annihilated in pairs and conserve their homotopy properties during their lifetime. Such kinks could prove relevant to astrophysical, geophysical, or laboratory plasma problems. We describe magnetic kinks with one axis of rotational invariance analytically and graphically. As an example, we examine their relevance to the puzzle of the origin of galaxies.Supported by the est Foundation and the National Science Foundation.     

实验室天体物理研究进展

近年来,随着高功率激光实验装置的广泛应用,成像技术和模拟分析技术水平的进一步提高,实验室天体物理研究取得了一些新的重要进展,如激光等离子体实验中对流等离子体磁场结构,冲击波中磁场的湍流放大效应,实验室模拟原恒星喷流中磁场的准直效应和太阳风与偶极磁场之间相互作用等方面的研究。这些研究加深了人们对原恒星以及Herbig—Haro天体喷流、超新星遗迹冲击波、地球磁层中磁场活动等天体物理现象的理解。文章对上述几个方向进行了介绍,并对未来研究方向做一些展望。     

Selected topics in nuclear astrophysics

In this lectures after a brief introduction to stellar reaction rates and its implementation in nuclear networks I discuss the nuclear aspects of the collapse of the inner core of massive stars once it has run out of its nuclear energy source and of the star's explosion as a type II supernova and the explosive nucleosynthesis occurring during this explosion which leads to the production of heavy elements by the rapid neutron capture process and potentially also by the recently discovered νp process.     

Highlights in black hole astrophysics

I review the theoretical and observational data supporting the existence of black holes at various mass scales and then give a brief account of the recent progress in the understanding of the stellar tidal disruption process, which is expected to play a prominent role in fuelling large black holes in galactic nuclei.     

Nuclear clustering aspects in astrophysics

Atomic nuclear clusters play a crucial role in nucleosynthesis in the universe, especially in the main sequence of heavy element synthesis. Cluster aspects in nucleosynthesis are briefly discussed based on a Cluster-Nucleosynthesis Diagram proposed here. Two recent topics on critical α-induced thermonuclear reactions are reviewed; the first one is the¹²C(α, γ)¹⁶O reaction for the He burning stage and the other one is the⁶ Li(α, n) ¹¹B reaction for the big bang nucleosynthesis. A new field of nuclear astrophysics using radioactive nuclear beams is also discussed.     

Mini-bangs in cosmology and astrophysics

The ideas originally proposed to discuss continuous creation of matter are reconsidered in the context of the big bang cosmological models. It is shown that singularity-free big bang models are possible under the modified field equations of general relativity. However, the case is made out that matter creation takes place in several mini-bangs at different epochs rather than in one big bang. The implications of this idea for high energy astrophysics and for gravitational radiation are discussed.     

Some nonlinear problems in astrophysics

Astrophysical magnetic fields, in the hydromagnetic approximation, pose a rich class of nonlinear problems. Of primary interest is the behavior and properties of the magnetic field interacting with the plasma in the presence of gravity. Substantial progress has been made recently with these problems arising in the study of interstellar clouds, stellar structures and magnetospheres, and structures on the Sun, such as prominences, sunspots and coronal magnetic fields. This paper reviews recent theoretical work, concentrating on steady state problems and emphasizing the use of analytic methods.     

TMSR白光中子源关键核数据实验进展

钍铀燃料循环核数据的精度和可靠性直接关系着钍基熔盐堆的安全性和经济性。目前大多数核数据都是基于铀钚燃料循环进行开发,若直接用在钍基熔盐堆上将会出现核设计不确定度较高的问题。为了提高钍基熔盐堆物理设计所需核数据的适用性,中国科学院上海应用物理研究所自行设计并建造了紧凑型的15 MeV电子加速器驱动的白光中子源(Photoneutron Source,PNS),用于开展钍铀燃料循环核数据的实验测量。该装置已通过技术验收,并进行了一系列关键核素的核数据测量,检验了现用核数据的可靠性,为相关核素的核数据评价与改进提供了基础实验数据。