基于HIRFL-CSR测量丰中子重核质量的建议

丰中子重核区有大量原子核质量未知,迫切需要实验测量。我们建议,利用兰州重离子加速器研究装置HIRFL-CSR上的等时性质谱术,高精度测量204Pt等丰中子重核的质量。CSR质量测量实验中,在目标核产额尽可能高的前提下,需要每次注入都有多个离子同时储存到实验环CSRe中,才能针对逐次注入修正磁场晃动的影响,得到高精度测量结果。但在丰中子核区,当目标核产生截面非常低时,每次注入能储存到环中的离子数目太少。为了解决这个问题,我们提出了一种"混合厚度靶"的方法,在不明显改变目标核产额的情况下,显著增加同时储存在CSRe中的离子数,满足实验要求。模拟计算表明,在CSRe测量丰中子重核质量是可行的,并推荐了实验的设置。     

放射性核束(RIB)的物理前沿

介绍了世界上主要的放射性核束装置,并对当前放射性核束物理研究的前沿方向作了评述．同时,也展望了放射性核束装置的发展趋势．Several Radioactive Ion Beam (RIB) lines are briefly introduced in this paper, and the main frontier fields of RIB physics are reviewed.In the last section,the developing trends of RIB setup are prospected.      

碎裂反应和放射性核束的产生

本文总结了中能重离子碰撞产生同位素分布的计算方法和模型 ,包括参数化公式 ,擦碎模型和统计擦碎模型。介绍了模型的物理基础和计算方法 ,并讨论了对擦碎模型和统计擦碎模型的修正。同时用统计擦碎模型探讨了碎裂反应产生的同位素分布的同位旋效应。然后介绍了放射性核束的产生方法 ,并对放射性束流物理的发展前景作了简要介绍。     

放射性核束物理与核天体物理

基于兰州重离子加速器国家实验室 (HIRFL )的中能放射性核束线 (RIBLL)及北京串列加速器国家实验室 (HI- 1 3 )的低能放射性核束线 (GIRAFFE) ,开展放射性核束物理和核天体物理研究 ,拟解决的关键科学问题是 :远离β稳定线核的结构与反应 ;超重新核素及近滴线核素的合成和性质研究 ,极端同位旋非对称核物质特性和关键的天体核反应研究 .研究内容分成 7个课题 :(1 )晕核研究 ;(2 )新核素合成及超重新核素研究 ;(3 )丰中子核结构和反应 ;(4)丰质子核结构和反应 ;(5 )高自旋的同位旋相关性 ;(6 )关键天体核反应 ;(7)系统的理论研究 .上述研究也将是2005年建成的国家大科学工程——兰州冷却贮存环的主要科学目标的研究基础 .简述了近期的主要工作进展. Based on the intermediate energy radioactive Ion Beam Line in Lanzhou (RIBLL) of Heavy Ion Research Facility in Lanzhou(HIRFL) and Low Energy Radioactive Ion Beam Line (GIRAFFE) of Beijing National Tandem Accelerator Lab (HI-13) the radioactive ion beam physics and nuclear astrophysics will be researched in detail. The key scientific problems which will be researched as high priority are: the nuclear structure and reaction for nucleus far from β-stability line; the syntheses...     

BRISOL铝同位素放射性核束的产生

北京放射性核束装置在线同位素分离器(BRISOL)采用100 MeV回旋加速器提供的最大200μA的质子束打靶在线产生放射性核束。在BRISOL上已经使用氧化钙靶、氧化镁靶产生了Na⁺、K⁺等放射性核束。为了产生铝同位素放射性核束,研发了碳化硅靶材,开展了碳化硅靶产生铝放射性核束的实验研究。在BRISOL装置上首次产生了铝同位素放射性核束,其中^26gAl⁺的束流强度为8.7×10⁷ pps,²³Al⁺的束流强度为2.2×10² pps,同时将BRISOL靶能承受的质子束流强提升至15。     

核结构的新机遇

讨论核结构的新机遇及其发展特点.着重从大型实验设备和技术的革命性进步的角度,阐明核结构的新机遇和发展的坚实基础和保证.     

丰中子核63,65,67Mn的在束γ谱学研究

利用放射性束68Fe轰击液氢靶引起的敲出反应,研究了极端丰中子核63,65,67Mn的激发态,指认了它们的自旋宇称,建立了这三个原子核的能级纲图。纲图包含11/2–、9/2–和 7/2– 三个激发态以及$5/2_{\rm{g.s.}}^{-}$基态,它们由三条$\Delta I \!=\! 1$的$\gamma$跃迁连接。这种能级结构与$K \!=\! 5/2$时强耦合转动带的特征一致。使用改进的LNPS有效相互作用(LNPSm)的大规模壳模型计算能很好地重现观测到的能级。计算表明,65,67Mn的低位激发态都主要包含处于$4p{\text -}4h$的中子组态和$1p{\text -}1h$的质子组态。基于实验结果发现,在吸积中子星壳中,与质量数$A \!=\! 63$相关的Urca中微子冷却效果比预期的要强很多,而$A \!=\! 65, 67$的冷却效果比预期的更弱。     

碎裂反应和放射性核束的产生

本总结了中能重离子碰撞产生同位素分布的计算方法和模型,包括参数化公式,擦碎模型和统计擦碎模型。介绍了模型的物理基础和计算方法,并讨论了对擦碎模型和统计擦碎模型的修正。同时用统计擦碎模型探讨了碎裂瓜在产生的同位素分布的同位旋效应。然后介绍了放射性核束的产生方法,并对放射性束流物理的发展前景作了简要介绍。     

丰中子核105Mo单中子带结构的识别

通过对重核²⁵²Cf自发裂变产生的瞬发γ谱的测量, 对丰中子核¹⁰⁵Mo的能级结构进行了研究. 除确认与扩展了基带转动带外, 新识别了3个转动带, 它们分别被指定为建立在Nilsson能级3/2⁺[411], 1/2⁺[411]和5/2⁺[413]轨道上的单中子激发带, 并对这些集体带的特性进行了讨论.     

放射性核束为核物理和核天体物理提供的新机遇

简要介绍了有关放射性核束的研究状况,特别是它为核物理和核天体物理提供的研究机遇,,以及相对论连续谱Ｈａｒｔｒｅｅ－Ｂｏｇｏｌｉｕｂｏｖ的新进展。     

Nuclear Astrophysics with Radioactive Beams

Radioactive beams, either at low or high energy, can be very useful for understanding violent events which are encountered in nuclear astrophysics.     

放射性核引起的反应

评述了放射性核自身的特征和它引起的反应机制研究．论述了晕核、中子皮核、电磁断裂和软偶极共振以及放射性核所引起的弹性散射、转移反应和亚位垒融合等. The characteristic of the nuclei far from stability and the mechanism of the reactions induced by these nuclei are reviewed. The disscusion includes the structure beyond the dripline and examples of elastic and inelastic scattering,inverse kinematic and nuclear break up, and of subbarrier fusion using radioactive beams.     

Nuclear Moment Studies with Polarized Radioactive Nuclear Beams

Magnetic dipole and electric quadrupole moments of nuclei in the light-mass neutron-rich region have been studied by taking advantage of spin-polarized radioactive nuclear beams that have been obtained from the projectile fragmentation reaction. Analyses of the results reveal a few interesting phenomena characteristic of nuclear structures in this region. In particular, we report in some detail the latest result on the magnetic moment of the ¹⁷C ground state. The distinctly small value of the g-factor obtained, |g(¹⁷C)|=0.5054±0.0025, clearly excludes a I ^π=1/2⁺ candidate for the spin-parity assignment of this marginally bound nucleus, providing a reasonable account of the non-halo nature reported in recent breakup reaction experiments. Finally, future plans at the upcoming radioactive beam facility presently under construction at RIKEN are briefly mentioned. This revised version was published online in September 2006 with corrections to the Cover Date.     

Research with Trapped keV Ion Beams

Hyperfine Interactions - The motion of an ion bunch trapped between two electrostatic mirrors in an ion trap resonator has been studied. Under certain conditions the ion motion becomes correlated...     

重离子束治癌

本文回顾了辐射治癌的历史发展和国内外动态,讨论了重离子束与常规辐射相比在肿瘤治疗上的优势,提出了为治疗应用的重离子束的主要参数以及在兰州重离子研究装置（ＨＩＲＦＬ）拟建的冷却储存环（ＣＳＲ）上建立治疗实验室的初步考虑． Historical background and trends at home and abroad for radiation therapy arelooked back in the paper. The advantages of heavy ion beam in comparision with conventional radiation in tumour treatment are discussed. The main parameters of heavy ion beams fortherapy application and a tentative idea constructing treatment rooms at Cooling StorageRing(CSR) of Heavy Ion Research Facility in Lanzhou (HIRFL) are proposed.     

Intermediate Energy Coulomb Excitation of Neutron-Rich Nuclei

We reinvestigate the collective effects of the retardation as well as the bending on the Coulomb excitation cross sections and also on the B（E2） strengths of some neutron-rich isotopes using the intermediate energy Coulomb excitation theory. It is found that the B（E2） strengths extracted from the experimental Coulomb excitation cross section data get suppressed approximately by 6%. Furthermore, the obtained B（E2） strengths in the energy range 30-100 MeV/A are found to be in better agreement with the corresponding values known from other sources, than those obtained by using the recoil-corrected relativistic Coulomb excitation theory.     

Stability of Crystalline Ion Beams

Hyperfine Interactions - In this paper, the conditions for which three-dimensional crystalline ion beams were attained in the rf quadrupole storage ring PALLAS at a velocity of around 2800 m/s are...