CR-39核径迹探测器的标定试验

采用５０ＭｅＶ／ｕ＾１２Ｃ离子对ＣＲ－３９核径迹探测器进行了标定,初步获得拟合公式ＶＴ＝Ｃ·ＬＥＴＣＲ－３９＾α斜率Ｃ为０．００８３（μｍ／ｋｅＶ）＾１．４８５５μｍ／ｈ）,指数α为１．４８６５。     

47MeV／u的C^6^＋在CaVSn：YIG中辐照效应的研究

用兰州重离子研究装置（ＨＩＲＦＬ）首次进行了４７ＭｅＶ／ｕ的Ｃ＾６＾＋离子辐照ＣａＶＳｎ：ＹＩＧ的实验。通过穆斯堡尔效应和正电子寿命测量对４７ＭｅＶ／ｕ的Ｃ＾６＾＋离子在ＣａＶＳｎ：ＹＩＧ中的辐照效应进行了初步研究。发现辐照导致内磁场方向趋于各向同性分布，由穆斯堡尔谱未观察到非晶化现象。缺陷的数量随Ｃ＾６＾＋离子在样品中电子能量损失的增加而增加。     

核测量标准数据现状

比照新实验数据对１９９１ ＮＥＡＮＤＣ／ＩＮＤＣ核标准库的数据进行评价。结果显示，除＾１０Ｂ（ｎ，ａ）截面和１５ＭｅＶ以上能区的＾２３５Ｕ（ｎ，ｆ）截面数据有待调整外，从现有实验数据状况看，１９９１ＮＥＡＮＤＣ／ＩＮＤＣ核标准库的数据是合理可靠的，建议推广应用。     

中能重离子与^natW相互作用中Hf的同位素分布

用放射化学方法测量了４０ＭｅＶ／ｕ＾４０Ａｒ，１０＼６５ＭｅＶ／ｕ＾８４Ｋｒ，８０ＭｅＶ／ｕ＾１６Ｏ，１３５ＭｅＶ／ｕ＾１２Ｃ＋＾ｎａｔＷ反应中Ｈｆ的生成截面，得到了Ｈｆ的同位素分布。研究表明，利用ＨＩＲＦＬ能量的重离子和丰中子重靶作用，能以一定的截面生成Ａ＞１７０区丰中子新核素，Ｎ／Ｚ值高的炮弹有利于丰中子核素的生成，过高的炮弹能量对丰中子新核素的生成没有贡献。     

^95Zr,^140Ba和^147Nd产额的精确测定

用ＨＰＧｅ直接γ射线能谱法绝对测定热中子和８ＭｅＶ中子诱发＾２３５Ｕ裂变的＾９５Ｚｒ、＾１４０Ｂａ和＾１４７Ｎｄ的产额。绝对裂变率用双裂变室测定,并首次根据测定＾１９８Ａｕ的γ放射性活度来检验裂变室的效率。同时给出产额的“快热比”,以编评热能值为标准得到８ＭｅＶ点的产额值。结果证明,在８ＭｅＶ能点处,产额值偏离随中子能量变化呈ｅ指数关系。     

50MeV/u12C6+离子辐照B16细胞氧效应研究

实验以体外培养的小鼠Ｂ１６黑色素瘤细胞为材料,在５０ＭｅＶ／ｕ ＾１２Ｃ＾６＋离子的展宽Ｂｒａｇｇ峰区辐照细胞,得到的结果是这种离子的ＯＥＲ值为１．２５。说明这种能量的离子具有低的氧效应。     

16O6+辐照诱导的人肝癌细胞DNA双链断裂及其修复

用倒转脉冲场凝胶电泳（ＰＩＧＥ）研究了３．１７ＭｅＶ／ｕ＾１６Ｏ＾６＋诱导的肝癌细胞ＤＮＡ双链断裂（ＤＳＢ）及其修复效应。结果表明：ＤＳＢ的诱导与辐照剂 量呈正相关,其产额为０．４３ＤＳＢｓ／１００Ｍｂｐ：Ｇｙ,与＾６０Ｃｏγ射线相比相对生物学效应为１．６９。ＤＳＢ片段重接一半所需要的时间（ｔ１／２）剂量有关,剂量越大,ｔ１／２越长。重接的方式主要表现为小片从而连接为较大的片段。     

70MeV质子束轰击^72Ge靶放射性核产生率的计算

在理论计算有有关截面能要当好地符合实验数据的前提下，用核反应模型ＳＰＥＣ程序计算了７０ＭｅＶ质子束轰击＾７２Ｇｅ及其化合物Ｚｒ５Ｇｅ３厚靶所产生的几种主要放射性核的产生率，其中＾７２Ａｓ和＾７１Ａｓ的产生率比国外的估算值高２－３倍。     

30MeV／u^40Ar＋159Tb反应中用于中等质量碎片测量的BGO阵列探测器

报道３０ＭｅＶ／ｕ＾４０Ａｒ＋１５０Ｔｂ反应中用于中等质量碎片（Ｚ≥３）测量的△Ｅ（Ｓｉ）＋Ｅ（ＢＧＯ）望远镜阵列的测试结果，实验表明该探测器阵列中等质量碎片有较好的粒子鉴别能力。     

20MeV／u^40Ar离子与^238U相互作用中的靶余核

采用核化学技术测定了２０ＭｅＶ／ｕ＾４０Ａｒ离子与＾２３８Ｕ靶相互作用靶余核的生成截面，由此得到了该反应了电荷分布和质量分布。     

An outlook of heavy ion driven plasma research at IMP-Lanzhou

Since the successful completion of the cooling storage ring (CSR) project in China at the end of 2007, high qualitative heavy ion beams with energy ranging from keV to GeV/u have been available at the Heavy Ion Research Facility at Lanzhou (HIRFL). More than 10⁹ 1 GeV/u C⁶⁺ particles or 10⁸ 235 MeV/u Xe particles can be stored in the CSR main-ring and extracted within hundred nano-seconds during the test running, the beam parameters will be improved in the coming years so that high energy density (HED) conditions could be achieved and investigated there. Recent scientific results from the experiments relevant to plasma research on HIRFL are summarized. Dense plasma research with intense heavy ion beams of CSR is proposed here.     

Attenuation of ambient dose equivalent from neutrons by thick concrete, cast iron and composite shields for high energy proton, He, Ca and U ions on Cu targets for shielding design

Data on neutron dose attenuation by thick concrete, cast iron, and cast iron plus concrete composite shields for heavy ions and protons having high energies (200-1000 MeV/u) are necessary for shielding designs of high-powered heavy ion accelerator facilities. Neutron production source terms, shield material attenuation lengths, and neutron dose rate reduction effectiveness of the bulk shielding in the angular range from 0° to 125° were determined by the Particle and Heavy Ion Transport Code (PHITS) for beams of 300 and 550 MeV/u ⁴⁸Ca ions, 200 and 400 MeV/u ²³⁸U ions, 800 MeV/u ³He and 1 GeV protons. Calculated results of interaction lengths of concrete and cast iron were also compared with similar work performed by Agosteo et al., and to experimental and other calculated data on interaction lengths. The agreement can be regarded as acceptable.     

Interferometry analyses of pion and kaon for the granular sources for Au+Au collisions at (~SNN)~(1/2)=200 GeV

We examine the interferometry results of identical pion and kaon for the granular sources of quark-gluon plasma droplets for the Au + Au collisions at S_(NN)~(1/2) = 200 GeV.The effects of particle absorptions of pion and kaon on the results are investigated.We find that the absorptions lead to the decrease of the interferometry radii.After considering the absorptions,the interferometry radii of pion and kaon of the granular sources are in better agreement with the experimental data of the Au + Au collisions.     

A Monte Carlo Simulation of an Actual Segmented Calorimeter: A Study of Calorimeter Performance at High Energies

The computer code system CALOR has been used to simulate data taken with a large segmented liquid argon/iron calorimeter at Fermilab. The resulting energy and angular distributions along with the longitudinal and transverse shower shapes are compared to experimental data in the range 1-38 GeV. Results are presented extending the Monte Carlo simulations to 125 GeV. The energy resolution of an incident hadron can be determined with a resolution ?E/E = (7.6 + 29.2/?E)% and its direction with a resolution of ?(?) = 22.7 + 390/E) mrad (where E is in GeV).     

Influence of α-clustering nuclear structure on the rotating collision system

In recent years, the collective motion properties of global rotation of the symmetric colliding system in relativistic energies have been investigated. In addition, the initial geometrical shape effects on the collective flows have been explored using a hydrodynamical model, a transport model, etc. In this work, we study the asymmetric ~(12)C+~(197)Au collision at 200 GeV/c and the effect of the exotic nuclear structure on the global rotation using a multi-phase transport model. The global angular momentum and averaged angular speed were calculated and discussed for the collision system at different evolution stages.     

Development of MRPC technology for STAR-TOF

A prototype of multi-gap resistive plate chamber （MRPC） modules with 6 gas gaps of 220 μtm used for the time-of-flight （TOF） detectors has been developed by STAR TOF group. A tray （TOFr） composed of 28 MRPC modules was constructed and operated in STAR for the d＋Au collisions and Au＋Au collisions during 2003 RHIC and 2004 RHIC run. Results show its time resolution is 85 ps with the average efficiency of 95% and clear identification of K/π up to 1.6 GeV and proton/K up to 3.0 GeV.     

Charm hadron azimuthal angular correlations in Au+Au collisions at ■=200 GeV from parton scatterings

The dynamic evolution of the charm hadron in hot quark matter was studied in the framework of a multiphase transport (AMPT) model.We first reproduced the open charm hadron D_(0pT) spectrum in Au+Au collisions at sNN~(1/2)=200 GeV by triggering the cc production in AMPT,and then the elliptic flow of charm hadrons was described with different parton cascade cross sections.Charm hadron azimuthal angular correlations were proposed,and they are affected by the different parton crosssection parameter applied in the model,which can facilitate our understanding of the loss of collision energy of charm quarks in hot quark medium and can stimulate further experimental studies.     

Exotic nuclei arena in JHP

The exotic nuclei arena planned in the Japanese Hadron Project aims to accelerate various unstable nuclei produced in 1 GeV proton-induced reactions up to 6.5 MeV/u by means of heavy-ion linacs. The present status of research and development for the E-arena is briefly reported. The construction of the prototype facility to accelerate unstable beams up to 0.8 MeV/u is planned for 1992–1994, in which the existing cyclotron at INS is used as the primary accelerator.