Estimation of the resident＇s additional dose in bone-coal mining areas of the five provinces

This paper introduces the resident＇s additional dose in bone-coal mining areas. The increase of the annual additional effective doses accepted by the residents living in the carbide-brick houses, the staffs working in the carbide-brick houses and the miners working in the bone-coal mining areas of Hubei, Hunan, Jiangxi, Zhejiang and Anhui Provinces is caused by the rising of environmental radioactive level. The investigation of natural background radiation in the bone-coal mining areas indicated that both mining and utilizing bone-coal cause the rise of environmental radioactive level. The ranges of the annual additional effective dose accepted by the residents, staffs and miners is 1.9-6.8 mSv, 0.5-2.0 mSv and 8.2-71 mSv, and with an average of 3.8 mSv, 1 mSv and 40 mSv, respectively. The annual additional effective doses accepted by part residents and staffs exceed the dose limit of 1 mSv for public exposure, and part miners exceed the dose limit of 20 mSv for occupational exposure. And the contribution of dose caused by inhaled radon to the total additional effective dose is over 76%.     

Estimation of the Lyman-α signal of the EFILE diagnostic under static or radiofrequency electric field in vacuum

The electric field induced Lyman-α emission diagnostic aims to provide a non intrusive and precise measurement of the electric field in plasma, using a beam of hydrogen atoms prepared in the metastable 2 s state. The metastable particles are obtained by means of a proton beam extracted from a hydrogen plasma source, and neutralised by interaction with vaporised caesium.When a 2 s atom enters a region where an electric field is present, it undergoes a transition to the2 p state(Stark mixing). It then quickly decays to the ground level, emitting Lyman-α radiation,which is collected by a photomultiplier. The 2 s→2 p transition rate is proportional to the square of the magnitude of the electric field, and depends on the field oscillation frequency(with peaks around 1 GHz). By measuring the intensity of the Lyman-α radiation emitted by the beam it is possible to determine the magnitude of the field in a defined region. In this work, an analysis of the behaviour of the diagnostic under static or radiofrequency electric field is presented. Electric field simulations obtained with a finite element solver of Maxwell equations, combined with theoretical calculations of the Stark mixing transition rate, are used to develop a model for the interpretation of photomultiplier data. This method shows good agreement with experimental results for the static field case, and allows to measure the field magnitude for the oscillating case.     

Estimation of Number of Underground Miners in Chinese Coal Mines

According to the report of UNSCEAR 2000, there are 1.594 million coal miners in Chinese giant-medium coal mines in 1991, and the total annual output of theirs accounts for 60% of that of countrywide. However,     

Two-Dimensional Numerical Simulation of the DC Glow Discharge in the Normal Mode and with Einstein’s Relation of Electron Diffusivity

This paper presents an investigation of a DC glow discharge at low pressure in the normal mode and with Einstein’s relation of electron diffusivity.Two-dimensional distributions in Cartesian geometry are presented in the stationary state,including electric potential,electron and ion densities,longitudinal and transverse electrics fields as well as electron temperature.Our results are compared with those obtained in existing literature.The model used in this work is based on the first three moments of Boltzmann’s equation.They serve as the continuity equation,the momentum transfer and the energy equations.The set of equations for charged particles presented in monatomic argon gas are coupled in a self-consistent way with Poisson’s equation.A parametric study varying the cathode voltage,gas pressure,and secondary electron emission coefficient predicts many of the well-known features of DC discharges.     

Calibration method of HLS’s sensor used in SSRF

The site of Shanghai Synchrotron Radiation Facility （SSRF） is of complicated geological conditions, and a system to monitor the uneven subsidence of foundation and key parts （different kinds of magnets） of the accelerators is a necessity. Considering actual conditions of the accelerator structure and the assembling place, a new type of sensor of hydrostatic levelling system （HLS） has been designed. In order to obtain the required measurement accuracy, every HLS＇s sensor was strictly calibrated. In this paper, we introduce the special calibration method to establish the HLS. The method has been used in the calibration for vessel sensor for SSRF.     

Evaluation of the irradiation dose rate for marine biota in the region of the destroyed fukushima reactor (japan) in march–may 2011

The irradiation dose rate in March–May 2011 is evaluated for marine biota in the coastal zone near the destroyed Fukushima reactor and in the open sea. It is shown that for representative marine organisms (fish and mollusks) the irradiation dose rate did not exceed the safe level 0.4 mGy/h (10 mGy/day). In the open sea, 30 km from the nuclear power plant, the irradiation of marine biota is much lower than in the coastal zone near the nuclear power plant. A comparative evaluation is made of the irradiation dose rate for water organisms in the exclusion zones of the Eastern-Urals track of radioactivity and the Chernobyl and Fukushima nuclear power plants.     

Effectiveness analysis of the reactor operator’s adviser computer code

Testing of the computer code Reactor Operator’s Adviser on the No. 3 unit of the Leningradskaya nuclear power plant showed that the recommendations given in the code increase substantially (by a factor of 1.2) the minimum margin to the P2 level for the adjusted signal from the in-reactor detectors along the radius and decrease the maximum temperature of the graphite masonry by 12°C and the maximum nonuniformity factor of the energy release distribution by 3%. Operation for 3.5 h using the Reactor Operator’s Adviser code recommendations maintained the operational parameters characterizing the energy release distribution along the core radius and height within acceptable limits.     

Improved method for measuring the γ-ray absorbed dose rate in models of iron shielding of a thermonuclear reactor

An improved method of measuring the absorbed γ-ray dose rate usingCaSO ₄ andSrSO ₄ type thermoluminescent detectors in models of iron shielding of a thermonuclear reactor is described. The reactionT(d, n)⁴ He served as a neutron source. The method obtained makes it possible to determine the absorbed γ-ray dose rate in shielding without using computed information and relying only on experimental data on the rates of nuclear reactions in threshold detectors. 7 figures, 1 table, 9 references. Moscow Engineering-Physics Institute. Translated from Atomnaya énergiya, Vol. 86, No. 3, pp. 219–225, March, 1999.     

Experimental and computational determination of the dose characteristics of a standard source of γ-radiation

The absorbed dose in a calorimeter is compared with Monte Carlo calculations for a standard source of exposure dose of γ-radiation from ⁶⁰Co. It is shown that if the initial γ-radiation spectrum is known to a high degree of accuracy, then a mathematical model of the interaction of particles and γ-rays with matter can be used to calculate the absorbed dose in a detector and the exposure dose in air to within several percent. This makes it possible to develop an experimental-computational method of transferring the dimensional units for the exposure dose and dose rate from a static standard to working means of measurement and pulsed bremsstrahlung sources.     

Stopping power in a cylindrical system by the modified Bessel function’s method

On the basis of the general theory of stopping power for a system, where their electronic distributions are able to be treated as cylindrically symmetric, we derive the log-type formulae which are applied in the non-relativistic high-energy region. As well as the case of a free electron in a homogeneous system, we obtain analytically instructive solutions of stopping power in an inhomogeneous system of many-electrons, in which an effective impact parameter averaged over scattering angles is introduced. Numerical calculations are performed for fast protons into a Au〈1 0 0〉 string.     

Calculation of mean dose deposited in extended volumearound an ion path

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

Design of Main Control Console Software in EAST Neutral Beam Injector’s Control System for the First Beam Line

Neutral beam injector is one of the main plasma heating and plasma current driving methods for experimental advanced superconducting tokomaks (EAST). In order to realize visual operation of EAST neutral beam injector’s control system (NBICS), main control console (MCC) is developed to work as the human–machine interface between the NBICS and physical operator. It can meet the requirements of visual control of NBICS by providing a user graphic interface. With the specific algorithms, the setup of power supply sequence is relatively independent and simple. Displaying the real-time feedback of the subsystems provides a reference for operators to monitor the status of the system. The MCC software runs on a Windows system and uses C++ language code while using client/server (C/S) mode, multithreading and cyclic redundancy check technology. The experimental results have proved that MCC provides a stability and reliability operation of NBICS and works as an effective man–machine interface at the same time.     

Inhibitory effect of low dose irradiation on tumor metastases in tumor bearing in mice

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Monitoring System of EAST’s Nuclear Radiation

Neutron and Gamma detectors have been used to monitor the nuclear radiation in the environment (Jianping in Nucl Electron Detect Technol 19(1), 1999; Chai et al. in Nucl Electron Detect Technol 25(1), 2005), during the experimental advanced superconducting tokamak (EAST) discharging. This paper is focus on the EAST’s nuclear radiation monitoring. Based on the full and real-time need for monitoring of radiation, the placement of radiation’s detectors around the EAST and the environment is studied. To get the radiation’s value, this paper gives the design of the monitoring system and presents the system’s acquisition module which transforms radiation to voltage signal. For the long distance and uneven distribution of each detector, transforming and processing module is designed, and the comparator’s principle and RS-485 transmission protocol are reviewed, the circuits of the comparator and RS-485 used in this system are designed. Then a conversion module is presented to have communication with personal computer, and framework of the whole monitoring system is introduced.     

Evaluation of the calibration factors of neutron dose rate meters in a ~(241)Am–Be neutron field

Calibrations were performed for three types of neutron ambient dose equivalent rate meters, i.e., Aloka TPS-451C (Hitachi), KSAR1 U.06(Baltic Scientific Instruments), and Model 12-4(Ludlum), using a standard field of a ~(241) Am–Be source. The measured total neutron ambient dose equivalent rates, H*(10)'_( tot), were analyzed to obtain the direct neutron ambient dose equivalent rates,H*(10)'_(dir), using the ISO 8529-2-recommended generalized-fit method, semiempirical fit method, and reducedfitting method(RFM) fit methods. The calibration factor(CF), defined as the ratio between the conventional true value of the neutron ambient dose equivalent rates in a free field, H*(10)'_(FF), and H*(10)'_(dir), was evaluated as one of the important characteristics of the neutron meters in the present work. The fitting results show that the H*(10)'_(dir) values of the meters are in good agreement within the theoretical data within 4%. The averaged CFs of the three neutron meters were evaluated as 0:99±0:01, 1:00±0:03; and0:99±0:08, respectively. The largest standard uncertainty of these values was determined to be approximately18.47%(k=1). The standard uncertainty of the CFs obtained using the RFM method was less than 4.23%(k=1), which is the smallest uncertainty among the three methods.     

Adjustment of the Parameters in the Calculations of the γ-Production Data

Introduction The γ-production data are very important for the nuclear engineering, especially for the calculations of the radiation shielding. Because the experimental values of the γ-production data can not satisfy the needs of the nuclear engineering both in the quantity of the nuclei and in the energy region covered by them, as the supplement, the theoretical calculations of the γ-production data are indispensable. The γ-production data in the nuclear reactions induced by neutrons include the γ-production cross sections, the γ-energy spectra, the γ-multiplicities and the reaction cross sections of the (n,γ) and the (n,xγ) reactions, where the (n,xγ) reactions mean