液态水中重离子径迹结构及能量沉积分布的研究

介绍了重离子径迹结构及能量沉积分布理论研究的进展情况，给出了重离子Ｍｏｎｔｅ Ｃａｒｌｏ计算模型以及电子径迹中的能量沉积几率分布和重离子径向剂量分布等计算结果。     

液态水中重离子径述结构及能量沉积分布的研究

介绍了重离子径述结构及能量沉积分布理论研究的进展情况，给出了重离子ＭｏｎｔｅＣａｒｌｏ计算模型以及电子径迹中的能量沉积几率分布和重离子径向剂量分布等计算结果。     

空间重离子的鉴别

采用地面加速的重离子模拟空间重离子标定了CR－39固体核径迹探测器，通过物理分析和计算方法获得了一个数学表达式，这样就可以通过CR－39固体核径迹探测器上径迹的测量进行离子鉴别和能量估计。     

低能重离子及其碰撞产生的级联原子在生物材料中的直接作用范围

用Ｍｏｎｔｅ Ｃａｒｌｏ法模拟计算了３０ｋｅＶ和２００ｋｅＶ的Ｎ＾＋与１１０ｋｅＶ的Ｆｅ＾＋在模拟细胞中的射程分布和径迹结构，并将１１０ｋｅＶＦｅ＾＋模拟计算的结果与ＲＳＢ测量的结果相比较，发现计算与测量的结果吻合较好，离子的作用范围小于１μｍ。计算和实验的结果都说明能量相当低的重离子不大可能直接作用引起麦胚深层生物效应。     

SFEL高亮度注入器的设计和粒子动力学特性

使用国际通用程序ＥＴＰ，ＰＡＲＭＥＬＡ和自编程序ＰＬＳ－ＩＭ－６０等对高亮度注入器作了详细的优化设计和粒子动力学数值模拟，注入器出口的电子束品质的主要参数为：能量３．５ＭｅＶ，能散２％（６２％电子）微脉冲束团相宽～４ｐｓ（６２％电子）在第一根加速管出口的电子品质的主要参数为：能量３３ＭｅＶ，能散０．３％（６２％电子）微脉冲峰值电流～８０Ａ，束团相宽３ｐｓ（６２％电子）束归一化发射度２０－３０πｍｍ     

用CR—39固体径迹探测器测定重带电粒子的Bragg峰位

采用ＣＲ－３９固体径迹探测器，根据辐射损伤密度沿粒子的径迹分布规律，测定了经３、４ｃｍ空气降能和φ１ｍｍ孔准直的α粒子（５．１５ＭｅＶ）的Ｂｒａｇｇ峰位。对于通过３ｃｍ空气后能量降至～１．２ＭｅＶ的α粒子，在ＣＲ－３９中的Ｂｒａｇｇ峰位大约在７μｍ深度处，理论计算值在６．１４μｍ，实验值与理论值符合得较好。     

用CR－39固体径迹探测器测定重带电粒子的Bragg峰位

采用ＣＲ－３９固体径迹探测器，根据辐射损伤密度沿粒子的径迹分布规律，测定了经３、４ｃｍ空气降能和φ１ｍｍ孔准直的α粒子（５．１５ＭｅＶ）的Ｂｒａｇｇ峰位。对于通过３ｃｍ空气后能量降至～１２ＭｅＶ的α粒子，在ＣＲ－３９中的Ｂｒａｇｇ峰位大约在７μｍ深度处，理论计算值在６．１４μｍ，实验值与理论值符合得较好。     

兰州重离子加速器冷却贮存环计划简介

１　兰州重离子加速器现状及发展设想兰州重离子加速器（ＨＩＲＦＬ）现有系统包括电子回旋共振（ＥＣＲ）离子源、注入器（ＳＦＣ）及主加速器（ＳＳＣ）。该系统可以提供能量为１０ｋｅＶ／ｕ～１００ＭｅＶ／ｕ，从Ｃ到Ｔａ的低中能重离子束。１９９４年５月３日，成功...     

低能重离子在原子核乳胶中的径迹结构

利用ＭＤ－１００显微密度计和细丝测微计，测量了在核４－电子灵敏乳胶中的电荷为２≤Ｚ≤６，相对速率β〈０．１的低能重离子径迹宽度。实验结果表明；径迹宽度与Ｚｅｆｆ．β成正比，其结论与径迹形成的每化柱模型结论一致。     

用于微剂量学研究的无壁正比计数器系统

本文介绍了为模拟荷能重离子在等效生物组织中径迹和能量沉积分布研究而设计，制造的无壁正比计数器和探测系统，并利用放射源＾２３９Ｐｕ的α粒子（能量为５．１５５ＭｅＶ）在５００Ｐａ气压及工作气体为ＣＨ４（１０％）＋Ａｒ（９０％）下，对本探测器系统的分辨率与所加高压关系进行了实验，并就利用此探测器系统研究微剂量学的研究方法进行了讨论。     

The calculation of radial dose from heavy ions: predictions of biological action cross sections

The track structure model of heavy ion cross sections was developed by Katz and co-workers in the 1960s. In this model the action cross section is evaluated by mapping the dose-response of a detector to gamma rays (modeled from biological target theory) onto the radial dose distribution from delta rays about the path of the ion. This is taken to yield the radial distribution of probability for a "hit" (an interaction leading to an observable end-point). Radial integration of the probability yields the cross section. When different response from ions of different Z having the same stopping power is observed this model may be indicated. Since the 1960s there have been several developments in the computation of the radial dose distribution, in the measurement of these distributions, and in new radiobiological data against which to test the model. The earliest model, by Butts and Katz made use of simplified delta ray distribution functions, of simplified electron range-energy relations, and neglected angular distributions. Nevertheless it made possible the calculation of cross sections for the inactivation of enzymes and viruses, and allowed extension to tracks in nuclear emulsions and other detectors and to biological cells. It set the pattern for models of observable effects in the matter through which the ion passed. Here we outline subsequent calculations of radial dose which make use of improved knowledge of the electron emission spectrum, the electron range-energy relation, the angular distribution, and some considerations of molecular excitation, of particular interest both close to the path of the ion and the outer limits of electron penetration. These are applied to the modeling of action cross sections for the inactivation of several strains of E-coli and B. subtilis spores where extensive measurements in the "thin-down" region have been made with heavy ion beams. Such calculations serve to test the radial dose calculations at the outer limit of electron penetration. We lack data from which to test these calculations in regions close to the path of the ion aside from our earliest work on latent tracks in plastics, though it appears that the criterion then suggested for the threshold of track formation, of a minimal dose at a minimal distance (of about 20 angstroms, in plastics), remains valid.     

MONTE CARLO CALCULATION OF ENERGY DEPOSITION BY DELTA RAYS AROUND ION TRACKS

The radial distribution of dose around the path of a heavy ion has been studied by a Monte Carlo transport analysis of the delta rays produced along the track of a heavy ion based on classical binary collision dynamics and a single scattering model for the electron transport process.Result comparisons among this work and semi-empirical expression based delta ray theory of track structure,as well as other Monte Carlo calculations are made for 1,3MeV protons and several heavy ions.The results of the Monte Carlo simulations for energetic heavy ions are in agreement with experimental data and with results of different methods.The characteristic of this Monte Carlo calculation is a simulation of the delta rays theory of track structure.     

Track structure and energy deposition distribution of heavy ions in liquid water

Progress in theoretical research into track structure and energy deposition distribution of heavy ions in introduced,and some research results are given,such as a Monte Carlo model of heavy ion track structure calculation,frequency distribution of energy deposition inside a electron track and radial dose distribution around a heavy ion path.Moreover,research direction in future is also analysed.     

Monte Carlo study of molecular weight distribution changes induced by degradation of ion beam irradiated polymers

In this work we study a polymeric material that degrades upon irradiation due to the energy inhomogeneously deposited by heavy ion beams. Ion beam irradiation of polymers generates rather different effects than those induced by “classical” low ionizing particles such as electrons or gamma rays. This is due to the high electronic stopping power and the inhomogeneous distribution of deposited energy. This energy is transferred to the material within a small volume along the ion path forming the so called “nuclear track” or “latent track”. The track size primarily depends on the ion velocity, and it is determined by the secondary electrons (delta rays) generated along the ion trajectory. By means of Monte Carlo simulations we first obtained equilibrated polymer configurations using a coarse-grained model, and then investigated the spatially inhomogeneous chain scission process due to the passage of the ions. The number average molecular weight, weight average molecular weight and the polydispersity were calculated as a function of track radius, scission probability within the ion track and irradiation fluence. Finally we compared our results with a numerical implementation of a model for random homogeneous degradation.     

氮离子束注入与贯穿小麦种子的生物效应初步研究

采用４７．９ＭｅＶ／ｕ和２０．４ＭｅＶ／ｕ１４Ｎ（７＋）离子束对小麦种子进行生物学效应研究。结果表明：１）重离子的贯穿和注入对小麦种子的生长势均有明显的抑制作用，剂量越大，抑制作用越强，而且注入作用高于贯穿；２）在种子的根尖细胞中出现的染色体畸变具有多种类型，畸变频率高于对照组１９８～５９２倍，而且注入比贯穿作用强；３）注入和贯穿处理两者同样有明显的诱变作用，可引起ＤＮＡ的损伤和修复     

Calculation of mean dose deposited in extended volumearound an ion path

1IntroductionThedistributionofmeandoseinanextendedvolumetakenapproximatelyasthesizeofasensitiveelementinabiologicalcellaroundachargedparticleisveryimportanttothequantitativeinterpretationofbiologicalheavy-ioneffects.Byassumingthattheresponseofsmallsubvolumes(volumeofasensitiveelement)aroundanionpathisasifthesesubvolumeswereuniformlyirradiatedwithgamma-rayatthesamedose,theeffectsproducedinchargedparticlesirradiationmayberelatedwiththoseobservedinganuna-rayirradiation.[1'2]Thus,theresponseofamed…     

利用重离子束开展半导体器件单粒子效应的探讨

讨论了利用重离子研究宇航半导体器件单粒子效应（ＳＥＥ）时应重视的几个问题，即空间辐射环境中的重离子，粒子辐射对半导体器件的影响和利用重离子束进行ＳＥＥ测试，以及重离子和质子在器件单粒子效应研究中的关系，最后介绍单粒子翻转重离子显微学。     

A COMPUTER SIMULATION OF HIGH-DOSE ION IMPLANTATION INTO AMORPHOUS MATERIALS

A computer program MACA was developed for simulating high-dose ion implantation into amorphous solids. The topology of amorphous solids was modelled by adjusting the free flight path distribution between collisions, so that the radial distribution function will characterize the short - range order and long - range disorder of amorphous targets. A simulation example is given.     

核电站事故时放射性释放量和照射剂量的关系

本文借助于核电站假想事故条件下的放射性释放量,按不同的核素组,分组计算了其经各种照射途径对周围居民造成的剂量;并考虑了气象资料的统计数据,使得因天气条件两低估剂量的可能不超过5%;从而得到了与事故过程(涉及释放的核素谱)和天气条件无关的释放量和照射剂量间的关系。文中还讨论了释放时间、风速、释放高度和停留时间等对上述关系的影响;以及各核素组、各种照射途径对照射剂量的相对贡献。