动态离子束混合技术制备氧化铬薄膜的X射线光电子能谱与俄歇电子能谱研究

本文介绍的动态离子束混合技术制备氧化铬薄膜系在不锈钢基体上进行1keV氩离子束溅射沉积铬(同时通入一定量的O),并用100 keV的氩离子束或氧离子束轰击该样品.对两种离子束轰击形成的氧化铬薄膜进行了X射线光电子能谱(X-ray photoelectron spectroscopy,XPS)和俄歇电子能谱(Auger electron spectroscopy,AES)的分析研究.发现Ar 离子束制备的氧化铬薄膜主要是Cr2O3化合物,而O 离子束制备的氧化铬薄膜含有其它价态的铬氧化物.Ar 离子束制备氧化铬薄膜的污染碳少于O 离子束制备.与O 离子束制备相比较,相同能量的Ar 离子束轰击更有利于提高沉积的Cr原子与周围O2的反应性;Ar 离子束制备的氧化铬薄膜过渡层的厚1/3左右,较厚的过渡层显示了制备的薄膜具有较好的附着力.     

箍缩反射离子二极管产生的强流脉冲离子束特性

通过对离子束流密度分布的测量和对被离子束轰击的铜箔不同半径处表面微观形貌的分析,研究了200kV箍缩反射离子二极管产生的离子束特性。结果表明：轴线上离子束流密度最大。     

10cm×30cm矩形射频离子束源的研制

本文介绍了射频(Radio frequency,RF)感应耦合等离子体(Inductive couple plasma,ICP)离子束源的设计研究.该射频离子束源可工作于Ar,在使用四栅引出系统时,可获得100-1000 eV的离子束.当射频功率为900 W,在Ar为工作气体时,束流可达到600 mA.在束流为120 mA时,距源26 cm处,在主轴方向27 cm的范围内不均匀性小于±6%.该离子束源可作为大面积离子束刻蚀、离子束抛光等的离子束源.     

低能离子束加减速实验研究

为满足核物理实验的要求，需要提供能量10～100keV的离子束。欲获得如此大范围能量可调变的离子束，从离子源直接引出是难以实现的，并且，能量太低时，不利于离子束的传输。因此，现实可行的方案是选择一个固定的引出能量，在靶前采用加减速结构，将离子束减速到10keV或加速到100keV，实现离子束能量的调整。     

用于双离子束注入器的杂质消除系统

研制了一套用于双离子束注入器的杂质消除系统，该系统由两台速度选择器、1台单透镜和1台双孔选束光阑组成，可实现不同荷质比的两种离子束在同时传输过程中消除杂质离子。该技术已用于1台H⁺₂和He⁺两种离子束同时传输的50 keV双离子束注入器，实现了1台加速器同时产生、传输两种离子束，并同轴注入靶内，离子束纯度好于99.9%。     

离子束—中性束技术及离子束应用技术的发展动向

离子束－中性束技术和离子束应用技术是离子束技术中的两个重要方面，其发展方向取决于科学研究和应用技术开发的需要，本文简述了它们的现状和发展动向。     

重离子束水吸收剂量的电离法实验研究

重离子束水吸收剂量是开展重离子束治疗最基本的物理量。在开展重离子束水吸收剂量的量值复现研究前，需用间接测量的方法开展相关工作以熟悉实验条件。本文用传统电离法开展了能量400 MeV/u、具有6 cm展宽Bragg峰的碳离子束的水吸收剂量测量研究，并评价了重离子束条件下的相关电离室的极化、离子复合修正因子。在电离室的极化和离子复合修正项方面，重离子束水吸收剂量测量的相关不确定度分量显著大于60Co γ辐射水吸收剂量的相关值。用不同电离室测量重离子束水吸收剂量的结果在不确定度允许的范围内符合。以电离室测量为基础，开展更深入的包括量热法绝对测量在内的辐射剂量学研究，对进一步优化重离子束水吸收剂量测量的不确定度至关重要。     

As离子束混合形成硅化钨的卢瑟福背散射分析

本工作用卢瑟福背散射研究了离子束混合方法形成硅化钨的条件。通过对热烧结和离子束混合法的比较,结合X射线衍射分析相结构的结果,指出离子束混合法可降低形成二硅化钨所需的退火温度。观察到氧杂质对形成条件的影响,简单讨论了离子束混合形成硅化物的机理。     

MeV原子团簇离子束的产生、鉴定及其与固体的作用

介绍了北京大学 2× 1.7MV串列静电加速器实验室开发能量为MeV/atom的原子团簇离子束的情况以及对这些团簇离子束的鉴定手段。应用这些团簇离子束 ,使团簇粒子离子能量损失中的邻近效应研究和团簇离子束在单晶硅中引起的辐照损伤研究等工作得到了开展     

离子束生物技术在生命科学中的应用

我国科学家80年代发现了离子注入的生物效应,并将这一原理应用于诱变育种.本文介绍了离子束生物技术及原理,低能离子束注入生物学效应的研究,离子束生物技术在新疆的应用和发展.     

加速器驱动洁净能系统中的燃耗行为分析

研究了加速器驱动洁净核能系统（ADS）次临界反应堆内核素的演化。分析结果表明：ADS具有嬗变长寿命核废物的能力。从快堆和热堆的比较可知,ADS的快堆具有输出功率大、长寿命超铀放射性废物的累积水平低、裂变产物对反应堆反应性和能量增益影响小等优点。这些优点在利用U－Pu燃料循环的次临界堆中十分明显。对于利用Th-U燃料循环的次临界堆,热堆和快堆都是可以工作的;而对于U－Pu燃料循环的系统,快堆则是较好的选择。     

Effect of hydrocarbons on the efficiency of catalytic reactor of detritiation system in an event of fire

Detritiation system of a nuclear fusion plant is mandatory to be designed and qualified taking carefully into consideration all the possible extraordinary situations in addition to that in a normal condition. We focused on the change in the efficiency of tritium oxidation of a catalytic reactor in an event of fire where the air accompanied with hydrocarbons, water vapor, and tritium is fed into a catalytic reactor at the same time. Our test results on the effect of these gases on the efficiency of tritium oxidation of the catalytic reactor indicated; (1) tritiated hydrocarbon produces significantly by reaction between tritium and hydrocarbons in a catalytic reactor; (2) there is little possibility of degradation in the detritiation performance because the tritiated hydrocarbons produced in the catalyst reactor are combusted; (3) there is no possibility of uncontrollable rise in the temperature of the catalytic reactor by heat of reactions; and (4) saturated water vapor could temporarily poison the catalyst and degrades the detritiation performance. Our investigation indicated a saturated water vapor condition without hydrocarbons would be the dominant scenario to determine the amount of catalyst for the design of catalytic reactor of the detritiation system.     

Reaction Rate of Hydrolysis of Iodine

Absorption rates of dilute iodine vapor contained in air by aqueous mixtures of sodium hydroxide and boric acid were measured using a laminar liquid jet column absorber at 298 K. Absorption rates in this system are controlled by a series of complex reactions taking place in the liquid phase. The reaction rate constant of iodine hydrolysis in the aqueous phase was determined from the absorption rates observed under the conditions that the base-catalytic hydrolysis reaction of iodine can be considered to be irreversible and that other reactions can be neglected. The absorption rates calculated theoretically with the rate constant value obtained above were in good accordance with the whole experimental data observed for a wide range of experimental conditions.     

高温堆非纯氦气中预氧化对3种高温合金的腐蚀行为影响研究

高温气冷堆（简称高温堆）中,由于一回路冷却剂氦气中含有微量（ppm级）不纯杂质,其在高温环境中会对高温堆合金材料造成腐蚀,影响设备的性能。Inconel 617、Hastelloy X、Incoloy 800H是3种高温堆中间换热器及蒸汽发生器设备候选材料。研究表明,镍铬合金在高温下表面生成的富铬氧化层是防止合金在高温下发生严重腐蚀的重要因素。本文对3种合金在高温含杂质氦气中的腐蚀行为进行研究,探究预氧化对3种合金腐蚀行为的影响。并通过称重、扫描电镜、X射线能谱、电子探针显微分析仪以及碳硫分析仪对腐蚀结果进行分析。结果表明,3种合金均出现了不同的氧化和渗碳现象,预氧化对Hastelloy X合金抗腐蚀能力的提升不明显,对Inconel 617合金的抗氧化和渗碳能力有一定提升,对Incoloy 800H合金的抗渗碳腐蚀能力有一定提升。     

空气中不同形态氚取样方法

空气中氚的存在形态主要是氚化水蒸气（HTO）、氚气（HT）和氚化甲烷（CH3T）。空气中的氚含量很低,测定通常采用累积取样和液闪谱仪测量相结合的方法。本文综述了空气中不同形态氚的取样方法的研究进展,对不同取样方法进行了比较分析,总结了不同取样方法存在的问题和不足,为空气中氚的取样方法研究提供参考。     

核电项目工程量概念解析

在市场化大趋势的推动下,核电项目的成本管理意识空前强化。在众多成本管理的影响因素中,工程量是决定性因素。本文从概念区分的角度划分了核电项目实施过程的活动层次,进行了相应分析,找出了各个层次活动量的不同测量方式,通过对这些方式的本质解析和整合,既澄清了施工项目工程量概念本身,也澄清了一些模糊认识,为工程量的管理和成本管理的改进奠定了必要的基础。     

Design of snowflake-diverted equilibria of CFETR

The Chinese Fusion Engineering Test Reactor (CFETR) represents the next generation of full superconducting fusion reactors in China.Recently,CFETR was redesigned with a larger size and will be operated in two phases.To reduce the heat flux on the target plate,a snowflake (SF) divertor configuration is proposed.In this paper we show that by adding two dedicated poloidal field (PF) coils,the SF configuration can be achieved in both phases.The equilibria were calculated by TEQ code for a range of self-inductances li3.The coil currents were calculated at some fiducial points in the flattop phase.The results indicate that the PF coil system has the ability to maintain a long flattop phase in 7.5 and 10 MA inductive scenarios for the single null divertor (SND) and SF divertor configurations.The properties of the SF configuration were also analyzed.The connection length and flux expansion of the SF divertor were both increased significantly over the SND.     

包覆颗粒燃料分布随机性的影响研究

高温气冷堆采用弥散在石墨基体中的包覆颗粒燃料。包覆颗粒在燃料球内的离散分布及燃料球在堆芯内的离散分布共同导致了燃料分布的双重不均匀性,其分布还具有随机性,由此可能对反应堆的某些参数造成影响。建立适当燃料颗粒随机分布的几何模型,并用MCNP对模型进行相关计算,并与规则分布模型相比较,分析了分布的随机性对有效增殖因数的影响。结果显示,燃料颗粒随机分布会使全堆有效增殖因数较规则模型的稍大,两种模型偏差的主要原因在于两种颗粒排列方式在空间和角度分布的不同。     

Challenge of transmutation of long-lived nuclides

Transmutation of radioactive nuclides into stable or short-lived ones has been under discussion as a measure to deal with the wastes of nuclear technology since its very beginning. There has been a lot of research activities world-wide with various approaches to transmuter design, matrix for waste incorporation and end waste form. This diversity comes from differently formulated transmutation priorities which, in their turn, originated in differently formulated strategy for development of nuclear fuel cycles. The present paper aims at surveying the goals of waste transmutation in view of trends identified in the past decade and address some new characteristics for estimating its radiological cost.     

Investigation of decay modes of superheavy nuclei

A detailed investigation of different decay modes,namely alpha decay,beta decay,cluster decay,including heavy particle emission(Zc＞28),and sponta-neous fission,was carried out,leading to the identification of new cluster and beta-plus emitters in superheavy nuclei with 104≤Z≤126.For the first time,we identified around 20 beta-plus emitters in superheavy nuclei.Heavy-particle radioactivity was observed in superheavy elements of atomic number in the range 116≤Z≤126.292-293 Og were identified as 86Kr emitters,and 298122 and 300122 were identified as 94Zr emitters,whereas heavy-particle radioactivity from 91Y was also observed in 299123.Fur-thermore,the nuclei 300124 and 306126 exhibit 96Mo radioactivity.The reported regions of beta-plus and heavy-particle radioactivity for superheavy nuclei are stronger than those for alpha decay.The identified decay modes for superheavy nuclei are presented in a chart.This study is intended to serve as a reference for identifying possible decay modes in the superheavy region.