28.7MeV/u的 14，16，18 O+7，9Be反应中的同位素分布研究

用同位旋相关的Boltzmann-Langevin方程研究了在入射能量为28.7MeV/u下,不同弹核^14O,^16O和^18O轰击不同靶核^7Be和^9Be的反应,计算了生成碎片的产生截面,发现用丰中子（缺中子）炮弹或丰中子（缺中子）靶进行反应,所得到的产物均有丰中子（缺中子）的碎片出现。同位素分布宽度和峰位与入射体系密切相关,产生碎片的电荷数越接近入射弹核的电荷数,则同位素分布的宽度越大,峰位偏离β稳定线值越远,其同位旋效应越明显。。     

Probing the nuclear symmetry energy with heavy-ion reactions induced by neutron-rich nuclei

Heavy-ion reactions induced by neutron-rich nuclei provide a unique means to investigate the equation of state of isospin-asymmetric nuclear matter, especially the density dependence of the nuclear symmetry energy. In particular, recent analyses of the isospin diffusion data in heavy-ion reactions have already put a stringent constraint on the nuclear symmetry energy around the nuclear matter saturation density. We review this exciting result and discuss its implications on nuclear effective interactions and the neutron skin thickness of heavy nuclei. In addition, we also review the theoretical progress on probing the high density behaviors of the nuclear symmetry energy in heavy-ion reactions induced by high energy radioactive beams.      

Using plastic track detectors to solve radiation safety problems at nuclear reactor facilities

Three options of the method to determine microconcentrations of fissile materials in water solutions are developed. They utilize plastic track detectors to measure concentrations. The options are as follows a “wet” method, “thin-layer inorganic sorbent-plastic track detectors”, and a method of selective extraction and coprecipitation. These methods are used to check up fuel cladding integrity at the research reactor IVV-2M and liquid radioactive waste contamination by uranium and plutonium at the Beloyarskaya Nuclear Power Plant (BNPP).     

放射性污染物粘膜铺设车控制系统设计

放射性污染物粘膜铺设车是核事故应急的一种主要装备。为解决放射性污染物粘膜铺设车多工位实时操控需要,设计了由主控屏、辅控屏和手持终端三种控制终端共同组成上位机的控制系统。该系统以主控屏作为交互中心,通过标准RS232接口与下位机通信;辅控屏和手持终端作为主控屏外设,分别通过CET-5E网线和蓝牙将数据实时传输至主控屏,实现不同工位下的可靠操控。下位机主控制器以ARM7作为主处理器,采用Modbus通信协议与上位机通信,便于系统后续拓展开发。实验表明,该多终端操控系统不受辐射环境干扰,通信稳定,操作便捷,实时性高,符合粘膜铺设车作业工况要求。这种通过主屏地址映射实现多终端控制的方式,有利于降低主控制器仲裁压力、减少数据冗余、提高系统时效,适合在各种特种车辆的控制系统中推广应用。     

Integrated target-ion source unit for on-line production of radioactive short-lived isotopes

A new version of integrated target-ion source unit (ionising target) has been developed for the on-line production of radioactive single-charged ions. The target is able to withstand temperatures up to 2500 ^°C and acts also as an ion source of the surface and laser ionisation. Off-line and on-line experiments with the ionising target, housing tantalum foils as a target material, have been carried out at the IRIS (Investigation of Radioactive Isotopes on Synchrocyclotron) facility. The off-line surface ionisation efficiency measured for stable atoms of Li, Rb and Cs was correspondingly 6% , 40% and 55% at the target temperature of 2000 ^°C and 3-10% for atoms of rare-earth elements Sm, Eu, Tm and Yb at a temperature of 2200 ^°C. The off-line measured values of the ionisation efficiency for stable Gd and Eu atoms by the laser beam ionisation inside the target were 1% and 7%, respectively. The radioactive beam intensities of neutron-deficient rare-earth nuclides from Eu to Lu produced by the integrated target-ion source unit have been measured at a temperature of 2500 ^°C. The results of the integrated target-ion source unit use for on-line laser resonance ionisation spectroscopy study of neutron-deficient Gd isotopes have been also presented.     

Natural radioactivity levels and associated health hazards from the terrestrial ecosystem in Rosetta branch of the River Nile,Egypt

Twenty soil and 25 sediment samples were collected from the banks and bottom of the River Nile in the surroundings of biggest cities located close to it. Natural radioactivity concentrations of ²²⁶Ra, ²³²Th and ⁴⁰K have been evaluated for all samples by means of γ spectrometric analysis. The radioactivity levels of soil and sediment samples fall within the internationally recommended values. Nevertheless, high natural background radiation zones are detected in the Kafr El-Zayat region due to the presence of a fertilizer factory, and in the Rosetta region due to the presence of black sand deposits. The absorbed dose rate, the γ index and excess life time cancer risk are calculated. High values for some of the radiation health parameters are detected in the Kafr El-Zayat and Rosetta regions representing a serious problem to public health because the soil and sediment are used as constructing material for buildings. Furthermore, the isotope analysis of uranium for representative collected sediment samples via α spectrometry showed average specific activities of 18.7?±?3.6, 0.087?±?0.0038 and 18.6?±?3.8 Bq kg^–1 for ²³⁴U, ²³⁵U and ²³⁸U, respectively. In general, these values confirm the balance in the isotopic abundance of U isotopes.     

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。     

Fission products from the damaged Fukushima reactor observed in Hungary

Fission products, especially ¹³¹I, ¹³⁴Cs and ¹³⁷Cs, from the damaged Fukushima Dai-ichi nuclear power plant (NPP) were detected in many places worldwide shortly after the accident caused by natural disaster. To observe the spatial and temporal variation of these isotopes in Hungary, aerosol samples were collected at five locations from late March to early May 2011: Institute of Nuclear Research, Hungarian Academy of Sciences (ATOMKI, Debrecen, East Hungary), Paks NPP (Paks, South-Central Hungary) as well as at the vicinity of Aggtelek (Northeast Hungary), Tapolca (West Hungary) and Bátaapáti (Southwest Hungary) settlements. In addition to the aerosol samples, dry/wet fallout samples were collected at ATOMKI, and airborne elemental iodine and organic iodide samples were collected at Paks NPP. The peak in the activity concentration of airborne ¹³¹I was observed around 30 March (1–3 mBq m^?3 both in aerosol samples and gaseous iodine traps) with a slow decline afterwards. Aerosol samples of several hundred cubic metres of air showed ¹³⁴Cs and ¹³⁷Cs in detectable amounts along with ¹³¹I. The decay-corrected inventory of ¹³¹I fallout at ATOMKI was 2.1±0.1 Bq m^?2 at maximum in the observation period. Dose-rate contribution calculations show that the radiological impact of this event at Hungarian locations was of no considerable concern.     

Treatment of Low and Medium Active Waste by Hexacyanocobaltate(III)

The commercially available CO₃[Co(CN)₆]₂·12H₂O was used in this study as inorganic ion exchanger. The uptake of caesium and cobalt from simulated borate reactor waste on the exchanger was conducted as a function of pH and concentration of caesium or cobalt in solutions. The same study was also carried out on the sorption of caesium from simulated medium active waste. In addition some experiments were carried out on the sorption of radionuclides present in a real medium active waste concentrate.