CONCLUSION OF INTERNATIONAL SYMPOSIUM ON NUCLEAR ENERGY AND THE ENVIRONMENT AT BEIJIN ON 14～18 OCT.1996

ＣＯＮＣＬＵＳＩＯＮＯＦＩＮＴＥＲＮＡＴＩＯＮＡＬＳＹＭＰＯＳＩＵＭＯＮＮＵＣＬＥＡＲＥＮＥＲＧＹＡＮＤＴＨＥＥＮＶＩＲＯＮＭＥＮＴＡＴＢＥＩＪＩＮＯＮ１４～１８ＯＣＴ．１９９６Ｂ．Ｇ．Ｂｅｎｎｅｔ（ＵＮＳＣＥＡＲ）Ｗｅｈａｖｅｃｏｍｅｔｏｔｈｅｅｎ...     

RADIOIMMUNOTOXICOLOGICAL EFFECT OF ENRICHED URANIUM ON CENTRAL AND PERIPHERAL IMMUNE CELLS AND THE PROTECTIVE ACTION OF IL－1 AND IL－2

ＲＡＤＩＯＩＭＭＵＮＯＴＯＸＩＣＯＬＯＧＩＣＡＬＥＦＦＥＣＴＯＦＥＮＲＩＣＨＥＤＵＲＡＮＩＵＭＯＮＣＥＮＴＲＡＬＡＮＤＰＥＲＩＰＨＥＲＡＬＩＭＭＵＮＥＣＥＬＬＳＡＮＤＴＨＥＰＲＯＴＥＣＴＩＶＥＡＣＴＩＯＮＯＦＩＬ－１ＡＮＤＩＬ－２￥ＺｈｕＳｈｏｕｐｅ...     

EXTRACTION OF AMERICIUM AND LIGHT RARE EARTHS BY 2－ETHYL HEXYL PHOSPHONIC ACID 2－ETHYL HEXYL ESTER

ＥＸＴＲＡＣＴＩＯＮ　ＯＦ　ＡＭＥＲＩＣＩＵＭ　ＡＮＤ　ＬＩＧＨＴ　ＲＡＲＥ　ＥＡＲＴＨＳ　ＢＹ　２－ＥＴＨＹＬ　ＨＥＸＹＬ　ＰＨＯＳＰＨＯＮＩＣ　ＡＣＩＤ　２－ＥＴＨＹＬ　ＨＥＸＹＬ　ＥＳＴＥＲＺｈｕＹｏｎｇｊｕｎ（朱永）ａｎｄＪｉａｏＲｏｎｇｚｈ...     

NASOPHARYNGEAL CARCINOMA RADIOSENSITIVITY PREDICTION BY CYTOKINESIS－BLOCK MICRONUCLEUS ASSAY

ＮＡＳＯＰＨＡＲＹＮＧＥＡＬ　ＣＡＲＣＩＮＯＭＡ　ＲＡＤＩＯＳＥＮＳＩＴＩＶＩＴＹ　ＰＲＥＤＩＣＴＩＯＮ　ＢＹ　ＣＹＴＯＫＩＮＥＳＩＳ－ＢＬＯＣＫ　ＭＩＣＲＯＮＵＣＬＥＵＳ　ＡＳＳＡＹＹａｎｇＸｉｎｇ（杨星）；ＳｈｉＪｉａｎｈｕｉ（史剑慧）ａｎｄＣｈ...     

STIMULATING EFFECT OF LOW DOSE ~(147)Pm ON DNA REPAIR IN SPERMIOGENIC STAGES

ＳＴＩＭＵＬＡＴＩＮＧＥＦＦＥＣＴＯＦＬＯＷＤＯＳＥ~（１４７）ＰｍＯＮＤＮＡＲＥＰＡＩＲＩＮＳＰＥＲＭＩＯＧＥＮＩＣＳＴＡＧＥＳＳＴＩＭＵＬＡＴＩＮＧＥＦＦＥＣＴＯＦＬＯＷＤＯＳＥ~（１４７）ＰｍＯＮＤＮＡＲＥＰＡＩＲＩＮＳＰＥＲＭＩＯＧＥＮＩＣＳＴ...     

DETERMINATION OF SUPERFICAL ABSORBED DOSE FROMEXTERNAL EXPOSURE OF WEAKLY PENETRATING RADEATIONS

ＤＥＴＥＲＭＩＮＡＴＩＯＮＯＦＳＵＰＥＲＦＩＣＡＬＡＢＳＯＲＢＥＤＤＯＳＥＦＲＯＭＥＸＴＥＲＮＡＬＥＸＰＯＳＵＲＥＯＦＷＥＡＫＬＹＰＥＮＥＴＲＡＴＩＮＧＲＡＤＥＡＴＩＯＮＳＣｈｅｎＬｉｓｈｕ（陈丽姝）（ＣｈｉｎａＩｎｓｔｉｔｕｔｅｏｆＡｔｏｍｉｃＥｎ...     

ACCURACY OF MEASUREMENT OF NATURAL GAMMA RAY SPECTRA BY HD－8004 NaI（T1）GAMMA SPECTROMETER

ＡＣＣＵＲＡＣＹ　ＯＦ　ＭＥＡＳＵＲＥＭＥＮＴ　ＯＦ　ＮＡＴＵＲＡＬ　ＧＡＭＭＡ　ＲＡＹ　ＳＰＥＣＴＲＡ　ＢＹ　ＨＤ－８００４　ＮａＩ（Ｔ１）ＧＡＭＭＡ　ＳＰＥＣＴＲＯＭＥＴＥＲＺｈｕＧｕｏｑｉｎ（朱国钦）ａｎｄＺｈｅｎｇＲｅｎｓｈｕ（郑仁淑）（Ｄｅ...     

ON ATMOSPHERIC RADIO-ACTIVITY AND PEIPING WEATHER

ＯＮＡＴＭＯＳＰＨＥＲＩＣＲＡＤＩＯ┐ＡＣＴＩＶＩＴＹＡＮＤＰＥＩＰＩＮＧＷＥＡＴＨＥＲＢｙＫ．Ｃ．Ｗａｎｇ（王淦昌）ＤｅｐａｒｔｍｅｎｔｏｆＰｈｙｓｉｃｓＳｉｎｃｅｔｈｅｄｉｓｃｏｖｅｒｙｏｆｒａｄｉｏａｃｔｉｖｅｅｍａｎａｔｉｏｎｓｉｎｔｈｅａｔ...     

STUDY ON OCCURENCE FORM OF PLATINUM IN XINJIE Cu－Pt DEPOSIT BY NAA AND SCANNING PROTON MICROPROBE

ＳＴＵＤＹＯＮＯＣＣＵＲＥＮＣＥＦＯＲＭＯＦＰＬＡＴＩＮＵＭＩＮＸＩＮＪＩＥＣｕ－ＰｔＤＥＰＯＳＩＴＢＹＮＡＡＡＮＤＳＣＡＮＮＩＮＧＰＲＯＴＯＮＭＩＣＲＯＰＲＯＢＥＬｉＸｉａｏｌｉｎ，ＺｈｕＪｉｅｑｉｎｇ，ＧｕＹｉｎｇｍｅｉ，ｗｕＸｉａｎＫａｎｇ（Ｓ...     

MONTE CARLO CALCULATION FOR CALIBRATION FUNCTIONS IN TOTAL REFLECTION X－RAY FLUORESCENCE SPECTROMETR

ＭＯＮＴＥ　ＣＡＲＬＯ　ＣＡＬＣＵＬＡＴＩＯＮ　ＦＯＲ　ＣＡＬＩＢＲＡＴＩＯＮ　ＦＵＮＣＴＩＯＮＳ　ＩＮ　ＴＯＴＡＬ　ＲＥＦＬＥＣＴＩＯＮ　Ｘ－ＲＡＹ　ＦＬＵＯＲＥＳＣＥＮＣＥ　ＳＰＥＣＴＲＯＭＥＴＲＹＦａｎＱｉｎｍｉｎ（范钦敏）；ＬｉｕＹａｗｅｎ（...     

Standardization of 2H(d,n)3He Neutron Source by Total Absorption Method Using Water Bath

The total absorption method using water bath is applied to the case of an almost monoenergetic anisotropic neutron stream from artificial accelerator, to be used for standardizing the strength of a ²H(d, n)³He source.

A detailed neutron balance equation is derived by taking into consideration certain correction terms to account for the finite water bath and associated equipment in the source. An experimental procedure for calibrating the thermal-flux-distribution and monitor neutron detectors is established to permit determination of the total loss of thermal neutrons in the bath and of the source strength at a given reference time. This calibration of the monitor detector makes it possible to measure the source strength as a function of time during accelerator operation simply by measuring only the counting rate registered by the detector.     

铀浓度在线分析系统的研制

采用标准加入-γ吸收法原理研制了铀浓度在线分析系统。利用不同厚度金属片对γ射线吸收程度的差异,通过在样品池与放射源之间添加金属片的方式实现固体内标的加入。研究工作中对测量模块的结构、内标材料的选择及在线流路进行了设计,编制了在线分析软件。采用有机相铀溶液对在线分析系统进行了测试,6次测定的平均值与真实值的相对偏差在3%以内,分析系统连续运行72 h的稳定性在1%以内。测试结果表明,铀浓度在线分析系统性能稳定,准确度高,适用于核燃料后处理工艺复杂基体中铀浓度的在线测量。     

Angular-Dependent Electron-Capture Probabilities

The angular dependence of the electron capture probability for monoenergetic protons scattered off Ne atoms in fast binary encounters has been studied experimentally. A qualitative discussion of the physics of the angular dependence is presented and a simple model is developed which fits the experimental angular dependences well.     

Numerical Solution of the Spencer-Lewis Equation for Kilovolt Electron Transport in Plane Slabs

We have developed a computer program BOLT for the numerical solution of the Spencer-Lewis equation for kilovolt electron transport in finite slabs. The method of solution used is a discrete ordinates method utilizing Gauss-quadrature angles equivalent to a 20th order Legendre polynomical expansion of the electron flux distribution function. The ultimate goal of the program is to compute x-ray photoelectron emission from thin targets and energy and charge deposition profiles near solid-vacuum boundaries and at interfaces between materials of differing atomic number. In this paper results are presented for a uniformly distributed monoenergetic electron source function, anisotropic in angle with form (1 + ? cos ?). The values for the charge and energy flow and deposition profiles agree within a few percent with analytic solutions characteristic of an infinite medium and with Monte Carlo transport calculations using simulated electron trajectories. The equilibrium value for the net flow or "Compton current" for 30 kilovolt electrons is found to be about 7 percent higher than the analytic value while all other quantities are believed to be accurate to within 2 percent. The principal source of error appears to be in the evaluation of the collision integral involving the exceedingly narrow deflections characteristic of kilovolt electron scattering. The discretization error due to finite grid sizes in the discrete ordinates scheme used was found to be very small.     

New Continuous Slowing-Down Theory for Fast Reactor Spectra

A new analytic representation for fast neutron spectra is described, based on the continuous slowing-down theory using generalized slowing-down parameters ξ(u), γ(u) in order to taking account of inelastic scattering.

The theory is basically formulated for neutrons moderated from monoenergetic source. For fast reactor spectra calculations, the fission source is generated by means of fictitious inelastic scattering. Examples of calculation show good agreement with multigroup calculations.     

成像板扫描仪的灵敏度曲线标定

开展了通用公司Typhoon FLA 7000型成像板扫描仪的灵敏度曲线标定实验。利用超短脉冲激光-固体靶相互作用产生的超热电子源同时辐照了成像板与已标定的LiF热释光探测器（TLD）,通过相对标定方法得到该扫描仪在光电倍增管不同倍增电压下的灵敏度曲线,并对测得的灵敏度曲线进行了数值拟合。拟合结果表明,灵敏度曲线随电压增大呈双指数规律减小,且与已有文献报道的利用标准放射源标定获得的结果一致。该方法为在无标准放射源情况下成像板扫描仪灵敏度曲线标定提供了一种有效途径。     

Solution of Diffusion Equation in r-z Geometry by Finite Fourier Transformation

It is shown that the monoenergetic diffusion equation in multi-region r-z geometry can be solved by the finite Fourier transformation method which has successfully been applied to x-ygeometry. In this method, a system of linear algebraic equations is derived for Fourier coefficients of fluxes and currents at the material boundaries between regions of constant cross sections, and all the boundary values are determined by solving this equation.

Numerical examples are presented for a problem featuring a fixed source and multiple regions, and the results are compared with those obtained from the current difference method. It is shown that the present method yields a better result with relatively few terms of expansion.     

The design of “multiple energies from one source” in D-T neutron tube

To obtain multiple monoenergetic neutron sources and realize the on-site calibration of radiation monitoring equipment for nuclear-involved places,the structural characteristics and neutron source features of D-T neutron tube were analyzed;Monte Carlo method was adopted to simulate the effect of interaction between typical materials and different energy neutrons;multilayered shielding materials were combined and optimized to acquire the optimal scheme to shield the neutron sources from the neutron tube.On the base,a tapered alignment filtration construction was designed and Monte Carlo method was employed to simulate the effect of alignment construction.The result showed that the tapered alignment filtration construction can create monoenergetic neutrons including14.1 MeV,0.18 MeV and thermal neutrons and demonstrated good monochrome performance which provides multiple monoenergetic sources for the on-site calibration.     

Experimental results from an ECR source using an octupole

The large superconducting ECR source, ECREVIS (Louvain-la-Neuve) has shown better charge state distribution (CSD) than smaller sources like MINIMAFIOS or the Berkeley source. Computer simulation indicates that the reason could be a lower average electron energy in the smaller sources. It has been suggested by Jongen that the size of the magnetic gradients in the source could be the energy limiting factor, and that the average electron energy could be increased by replacing the usual sextupole by an octupole. After an extensive series of tests, the sextupole of the Berkeley source was replaced by an octupole. After modification, the CSD have been substantially improved in the direction of higher charge states, with a substantial reduction of low charge state intensity. The intensity of higher charge states like argon 14+ or krypton 18+ increased by one order of magnitude. The new CSD are now very similar to those of the large ECREVIS source, indicating a probable gain in average electron energy.