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1.
压水动力反应堆燃料元件安全性的监测与分析   总被引:1,自引:0,他引:1  
为了对1座压水型动力反应堆作燃料元件破损的现场监测,计算了一些裂变产物的主要γ光子用76.2mm×76.2mmNal探测器测量时产生的光电峰相对计数率随反应堆启动不同时间的变化,并作了监测中的干扰因素分析。计算和分析结果表明:在元件安全性监测中,最适合选择的γ光子能量是220.9keV(89Kr)、402.7keV(87Kr)、196.3keV(88Kr)、529.8keV(133I)和81keV(133xe)。在监测中存在的主要干扰因素是高能γ射线产生的湮没辐射、wal探测器周围pb屏蔽上产生的75keVX射线及由19O和16N产生的γ射线。在1座反应堆2次事故排除的元件安全性监测中,分析方法成功地得到了应用。  相似文献   

2.
用^54Mn、^57Co、^65Zn、^85Sr、^109Cd、^137Cs等核素发射的KX射线和I(KX)/I(γ)比值法在5 ̄40keV范围内对Si(Li)探测器的效率进行了刻度(不确定度小于2%)。在此基础上,用Si(Li)X射线谱仪系统和HPGeγ射线谱仪系统对核素^75Se和^113Sn的主γ射线和KX射线进行了测量,获得了^75Se和^113Sn的KX射线发射几率,并与文献报道值进行了  相似文献   

3.
张光明  王国干 《核技术》1995,18(9):557-559
使用片状法生长HgI2单晶片制砀20mm2×0.4mm探测器在常温下对59.5keVγ射线和5.9keVX射线的能量分辨率分别为1.9keV和900eV。已用于Cu、Pb、Zn等矿样分析,取得了新结果。  相似文献   

4.
电致冷高分辨率Si(Li)X射线能谱分析仪采用电阻反馈前置放大器,灵敏面积为28mm^2Si(Li)探测器,对^55Fe5.9keVX射线,能量分辨率(FWHM)为700eV左右,对探测器在不同温度下随偏压的变化,致冷功率与温度关系,冷却温度与时间关系进行了研究。  相似文献   

5.
本文报道自行组建的一台Ge(Li)-NaI(Tl)反符合γ谱仪的结构和性能。主探测器是φ61.5mm×56.0mm的同轴Ge(Li)探测器(灵敏体积为150cm ̄3),由φ88.9mm×76.2mm的圆柱形NaI(Tl)晶体和外、内径×高为254mm、88.9mm×305mm的环形NaI(Tl)晶体构成井型反符合探测器,主要的物质屏蔽层是100mm铅+15mm钢+5mm铜。Ge(Li)探测器对 ̄(60)Co1333keV能量的分辨率为2.4keV,峰康比为44,相对探测效率为24%。在反符合屏蔽条件下,谱仪在康普顿坪(358—382keV)和康普顿端(460—484keV)的抑制因子分别为5.O和5.4;康普顿区积分(50—595keV)抑制因子3.6,峰康比( ̄(137)Cs点源)为494。在100—2000keV能区屏蔽室内、外的积分本底比为1:131。加反符合和不加反符合条件下的积分本底抑制因子为3.5,加反符合后的积分本底为17.2cpm。当测量时间1000min、置信度95%时, ̄(137)Cs的最低可探测活度(判断限)为5.8mBq.24小时内, ̄(241)Am、 ̄(137)Cs和 ̄(60)Co  相似文献   

6.
自制一套^37Co源激发与K系X射线荧光(K-XRF)分析系统,用^37Co的keVγ射线激发工艺溶液中U,Pu的K系X射线荧光,用HPGe探测器-多道微机分析系统进行测量,并以122keVγ射线康昔顿散射线为内标,建立强度比-浓度校正曲线,快速同地测定了PWR乏燃料后处理工艺溶液中U,Pu浓度,测定范围为0.5-200g/L,精密度为5.0%-1.5%。方法适于PWR乏燃料后处理工艺中,U,Pu  相似文献   

7.
14MeV中子在φ600mm贫化铀球中造钚率测量   总被引:1,自引:1,他引:0  
使用中子活化技术对238U(n,γ)239U反应产物239U衰变后的239Np子体的278keVγ射线的绝对测量,获得了14MeV中子在600mm贫化铀球中的造钚率。其实验测量值为2.46±0.09。278keVγ射线用高纯锗探测器测量,探测器的有效计数效率用243Am源刻度。600mm贫化铀球由7层贫化铀球壳组成,球心有一80mm源腔,总重约2.1t。  相似文献   

8.
沈浩元 《核技术》1995,18(9):564-565
测量了不同温度条件下面积为49mm×49mm、厚3.5mm的Si(Li)探测器的I-V特性。Si(Li)-E-1和E-2探测器对^238Pu5.499MeV α粒子的能量分辨率例如为54.4keV和57.09keV。  相似文献   

9.
外延硅dE/dX探测器的研制   总被引:1,自引:1,他引:0  
本文介绍了厚度为5.2-6.0、10-13、19μm,有效面积为28-154mm^2的外延硅dE/dX探测器的研制工艺,主要用途,测试结果(对9.87MeV α粒子的能损△E的分辨率为56-128keV)和在核物理实验中的应用。  相似文献   

10.
锗γ谱仪^110mAg符合相加修正因子测量   总被引:5,自引:5,他引:0  
吉长余 《辐射防护》1999,19(6):420-425
通过在HPGe探测器表面及距探头28cm处分别测量形状相同的^110mAg(657.8keV)和^137Cs(661.6keV)体源的全能峰妆计数率,可在避开源活度,发射几度和自吸收修正等条件下,测得在探测器表面测量^110mAg657.8keVγ射线的符合相加修正因子F0;本文介绍了此测量方法的原理和测量结果。  相似文献   

11.
Zn-doped TiO2 catalysts were prepared using a sol-gel method and characterized by XPS,UV-Vis, BET, XRD in this study. Under the irradiation of simulant sunlight, the photocatalytic activity for the degradation of p-nitrophenol was studied too. After irradiation for 2.5 h, the degradation percentage of p-nitrophenol could rise to more than 80 %. The results showed that the spectrum absorption band edge of Zn/TiO2 powder does not broaden obviously comparing with pure TiO2 powder. Zinc exists as Zn (11). When calcined at 973 K, there is a new phase as ZnTiO3 in Zn/TiO2 catalyst. The order of photocatalytic activity of Zn/TiO2 catalysts calcined at different temperatures for p-nitrophenol is 773 K 〉 673 K 〉 873 K 〉 573 K 〉 973 K and the photocatalytic activity of Zn/TiO2 catalyst calcined at 773 K is better than TiO2 catalysts heated at the same temperature, and outclasses that of commercial TiO2 catalyst. It also showed that the photocatalytic degradation of p-nitrophenol follows first-order kinetics under the irradiation of simulant sunlight.  相似文献   

12.
Radiotherapy for the treatment of prostate cancer has been extensively explored in the past. Along with the comprehensive understanding of the biology of prostate cancer and rapid advances in terms of technology, the out- come of treatment for the patients with prostate cancer has improved. The authors review radiotherapy as the primary treatment for the disease, with particular emphasis on the technological advances from both the radiobiological and radiophysics aspects. Nonconventional fractionated irradiation like hyper- or hypo-fractionation has been imple- mented in the clinic, the final results still need to be confirmed in the future. Technological advances like IMRT, IGRT, in the last two decades have significantly improved the delivery of external radiotherapy to the prostate. This has re- sulted in an overall increase in the total dose that can be safely delivered to the prostate, which has led to modest im- provements in the biochemical outcome. However, establishing the standard therapy for prostate cancer remains con- troversial. It is hoped that the next decades will bring continued advances in the development of biologicals that will further improve current clinical outcomes.  相似文献   

13.
This paper introduces the injection and extraction control system design for SSRF,which is a distributed control system aimed at stability and reliability of the pulse power supplies,PPS(Personnel Protection System)and MPS(Machine Protection System).The hardware environment is mainly based on PLC(Programmable Logic Con- troller),and ARM(Advanced RISC Machine)is also applied for studying stability of the power supplies.WinCC and EPICS(Experimental Physics and Industrial Control System)have been selected as the platforms of SCADA(Super- visory Control and Data Acquisition).For unifying the interfacing to the control computer,all front-end equipments are connected via Industrial Ethemet.  相似文献   

14.
为研究含空气蒸汽在水平管内强制对流冷凝换热特性,基于对传热传质过程的分析,建立了管内为环状流与波状流条件下的流动冷凝换热模型。从潜热、显热和液膜3个环节对整个换热过程进行建模,最终得到计算局部冷凝换热系数的理论关系式。模型预测结果与实验数据的对比表明,二者相对偏差在±20%以内,验证了该换热模型的准确性与适用性。通过进一步的研究发现:从换热管入口至出口,随着冷凝的进行,管内换热主要热阻由液膜热阻向气液界面的凝结热阻转变;主流气体对流换热过程基本可忽略。  相似文献   

15.
Experiments were carried out to investigate the possible use of neutron backscattering for the detection of polyethylene (PE) sample buried in the soil. In detection of landmine by neutrons, the neutron detector and its shield play an important role. In this paper, the effects of graphite, heavy water, polyethylene and boric acid moderators on the flux of back scattered neutrons were investigated. We have also experimentally verified the effect of BF3 detector shield and obtained good agreement with theory.  相似文献   

16.
Accelerator database stores various static parameters and real-time data of accelerator. SSRF (Shanghai Synchrotron Radiation Facility) adopts relational database to save the data. We developed a data retrieval system based on XML Web Services for accessing the archive data. It includes a bottom layer interface and an interface applicable for accelerator physics. Client samples exemplifying how to consume the interface are given. The users can browse, retrieve and plot data by the client samples. Also, we give a method to test its stability. The test result and performance are described.  相似文献   

17.
Distributions of natural gamma-emitting radionuclides were determined in 93 oil samples collected from some petroleum fields in the western desert of Egypt. The radioisotope activities in the area under investigation lay in the range of (21 ± 4) to (38 ± 13) Bq?L-1 for 226Ra, (9 ± 2) to (15 ± 5) Bq?L-1 for 232Th, and (154 ± 28) to (303 ± 54) Bq?L-1 for 40K. The mean values were 27, 12, and 201 Bq?L-1, respectively. Among oils, variations in radionuclide ac- tivities could be on account of differences in TDS, HCO3, and Ba, with high or low pH. In this environment, oil prop- erties differently affected the mobilization of natural radionuclides. The range of 226Ra variation had been compared with available data from other countries. The calculated absorbed dose rate ranged from 22.33 to 32.66 nGy?h-1 in lo- cation (B) and (E) respectively, which was less than the accepted value.  相似文献   

18.
In this work,TTHMP was synthesized and labelled with 117m Sn.The preparation conditions,stability and lipophilicity of 117m Sn(IV)-TTHMP were investigated.Biodistribution of the complex in rabbits and mice was studied.It was found that the quantity of TTHMP and pH value of the prepararion solution had vital effects on the labeling yield of 117m Sn(IV)-TTHMP.It was also found that 117m Sn(IV)-TTHMP was hydrophilic and stable at room temperature and 37℃ in open air 117m Sn(IV)-TTHMP showed unexpectedly high bone uptake and bone-to-blood ratio in the animals.This made it potentially useful as an reagent for skeletal scintigraphy and radiotherapy of bone tumors.  相似文献   

19.
Linear accelerators equipped with multileaf collimators (MLC) are becoming more common and are widely used in the intensity-modulated radiotherapy (IMRT). There is an imperative need to ensure the commissioning specification of the linear accelerators for the sake of quality assurance (QA) and quality control (QC). This paper is aimed to investigate the role of AGFA high-energy CR (Computed Radiography) in calibrating dynamic multileaf collimators and evaluating the accuracy of the leaf position. The result shows that AGFA high-energy CR can easily and conveniently be used to calibrate MLC and verify its position. Hence, the application of AGFA high-energy CR is proved to be an accurate and time-saving method for routine MLC QC, especially when MLC calibration adjustments are required.  相似文献   

20.
Monitoring results of gamma dose rate level in 1992~2004 in the ambient environment of the Qinshan Nuclear Power Plants(QNPP)Base,the northeast of Zhejiang Province,are reported in this paper.It is shown that the gamma dose rate of five monitoring sites of 2.5 km to QNPP Base is 84~113 nGy/h,with an average of 96 nGy/h in the 13 years.The average value is close to the background level of 93 nGy/h prior to operation of the QNPP Base,and is lower than the monitoring result of 101 nGy/h at the reference site in Hangzhou City.Within 50 km from the QNPP Base,the cumulative dose rate of the thermoluminescent dosimeter(TLD)is 90 nGy/h,which is lower than the back- ground level of 111 nGy/h.  相似文献   

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