二醋酸纤维素薄膜剂量计的制备和性能研究

为了改善醋酸纤维素薄膜剂量计在γ辐射剂量测定中稳定性欠佳的问题,拓展其辐射测量应用范围,采用离子液体均相乙酰化纤维素方法制得的二醋酸纤维素（CDA）粉末为原料,优化CDA薄膜制备工艺,研究其γ辐射变色性能及稳定性,制备适用于γ辐射剂量测量且性能优良的CDA薄膜剂量计。基于CDA的辐射变色机理,该薄膜剂量计在270 nm的单位厚度吸光度与吸收剂量存在良好的线性关系,剂量率、CDA的取代度和辐照气氛对薄膜的工作曲线影响较小。CDA薄膜剂量计的剂量检测量程为50~400 kGy,扩展不确定度为8.8%（K=2）,辐照后24 h内吸光度测试稳定,具有良好的辐照稳定性,基本满足工业上对于辐射剂量计的使用要求,有望应用于γ辐射剂量的测量。     

KF606B型氡和γ个人剂量计

本文介绍KF606B型氡(指222Rn,下同)和γ个人剂量计的结构和性能.剂量计采用固体核径迹探测器CR39和热释光探测器LiF(Mg,Cu,P),无源式累积测量方法.设计中考虑了氡测量开关(即非使用期间关闭氡测量)、防水、防尘等技术措施.在实验室和矿山现场实际应用中对剂量计各项性能进行了测试和验证,结果表明,剂量计具有适应矿山实际环境条件、灵敏度合适、探测下限较低等特点,并且体积小、重量轻、使用简便.目前该剂量计已定型生产,应用于铀矿、煤矿工作人员个人剂量监测和工作场所空气中氡浓度和γ辐射剂量率水平的调查测量,还用于居民室内氡浓度调查等工作中.     

包镉热释光剂量计测量热中子剂量的研究

在环境辐射监测中,不同材料的热释光探测器(TLD)已被广泛应用,但其中大多数(如CaSO_4、Al_2O_3、Mg_2SiO_4、BeO等)因对热中子不灵敏而不能测量热中子剂量。用包镉热释光剂量计可测量热中子,其特点是:(1)任何能测量X、γ辐射的TLD原则上都可应用;(2)剂量计对单位热中子剂量当量的响应标定不需要反应堆热中子源,可用~(60)Co-γ源代替。     

气泡中子探测器用于个人剂量监测

气泡中子探测器是可重复使用、积分型、无源剂量计。它的体积小,可对中子辐射进行直接、可视的测量。为了将气泡中子探测器用在个人剂量监测中,先验证气泡中子探测器对从0．2～15MeV能量的中子具有平直的能量响应。然后用5．10和1．3MeV的中子考察了气泡中子探测器的线性及其稳定性。     

低水平n-γ场监测用的新型个人剂量计

本文介绍一种TLD-85型多区个人剂量计,其探测下限低,对热中子灵敏度高,并可配用不同种类的热释光探测器,适用于热n-γ混合场中的个人剂量监测。     

超临界事故固体裂变径迹中子剂量计

阈探测器是研究中子能谱的一种有效工具,而中子能谱是解决某些辐射剂最学问题(其中包括确定紧急核事故中子剂量)所不可缺少的资料。用核乳胶和活化阈探测器测量事故中子剂量有一定的局限性。1967年,K.Becker 等人提出用“非照相方法”测量事故中子个人剂量的建议,并用天然铀和聚碳酸酯制作一种简单的裂变径迹个人中子剂量计~([1])。近年来,我们也研制了这种固体裂变径迹中子剂量计。在超临界紧急事故中,应用这种剂量计来测量中子剂量具有许多明显的优点:测量速度快,可测量的剂量范围大,环境适应性强和径迹计数能自动化等。其缺点是剂量计本身固有的γ放射性虽然已降低到很弱,但仍高出环境本底     

OSL剂量计的性能研究与测量不确定度评定

光致发光(OSL)剂量计是一种被动式累积个人剂量计,用于外照射个人剂量监测。与热释光剂量计(TLD)相比,它具有可重复测量、环境稳定性好、使用寿命长、信号衰退慢等优点。本文结合在个人剂量监测中应用OSL剂量计的工作经验,以OSL剂量计性能实验研究结果为基础,评价了OSL剂量计的最低可探测水平、角响应、能量响应、线性响应,并对OSL个人剂量测量系统的测量不确定度进行了评价。评价结果表明,在中国原子能科学研究院场区,OSL剂量计在1个月监测周期内的最低可探测水平(MDL)为0.04 mSv,角响应、能量响应、线性响应引起的偏差分别是1%、-14%、-4%。在95%的置信水平下,相对扩展不确定度为11.4%。     

光致荧光剂量计β辐照器的研制及性能研究

本文针对空间辐射、核动力远洋、核应急等特殊环境下个人及环境剂量监测量值无法实时校准的问题,研制了一种便携式的β辐照器,可携带至现场对光致荧光剂量计（OSLD）进行校准,为特殊环境下剂量监测的准确性提供计量保障。β辐照器采用可替换的⁹⁰Sr-⁹⁰Y平面电镀源作为校准源,并可溯源至标准β辐射场,通过电磁阀控制辐照动作,其总质量小于3 kg。研究结果表明：β辐照器周围剂量当量率处于环境水平;参考点平均剂量率为0.060~0.083 mGy/s,其相对标准不确定度为6.9%;辐照剂量重复性为3.9%（n=10）。     

中子气泡剂量计探测器用于混合中子场中子测量

气泡探测器具有中子实时剂量监测、宽能区中子能量响应稳定和探测限低的优势，因此，它在中子剂量计领域是一项有前景的技术。且被认为是唯一能满足国际放射防护委员会ICRP60要求的个人中子剂量计。目前，本实验室已经研制出具有自主知识产权的中子气泡剂量计。     

基于P-Si型半导体探测器的多通道剂量计

本文介绍一种应用于辐射场在线和实时检测、在核医学领域对受检患者放疗剂量进行监测和测量的多通道剂量计.该仪器采用了高精度的P-Si型半导体探测器.仪器经过初步应用,射线敏感能量区在0.1-15 MeV之间;最低探测灵敏度为0.05 Gy/min;输入偏流约为50×10-15 A;剂量线性理想,并配有打印机、LCD等设备,增加了仪器的智能性.     

Stopping powers of Be,Al, Ti,V, Fe,Co, Ni,Cu, Zn,Mo, Rh,Ag, Sn,Ta, Pt and Au For 6.5 MeV protons

The stopping powers of Be, Al, Ti, V, Fe, Co, Ni, Cu, Zn, Mo, Rh, Ag, Sn, Ta, Pt and Au for 6.5 MeV have been measured using a surface barrier silicon detector. The accuracy of the results is ± 0.3%. The detail of the experimental procedures is described. The results have been compared with the Risø data and the Aarhus data of Andersen et al. The present results for Al, Cu and Ag agree very well with the Aarhus results at 6.5 MeV. The mean excitation energy has been extracted from the present results using the Bonderup shell correction, the Barkas correction and the Bloch correction. The parameters x and b which appear in the Bonderup shell correction and the Barkas correction have been newly determined as x = 1.358 and b = 1.3. The present mean excitation energy agrees very well with the I values obtained by other authors. It has been confirmed that the Bonderup shell correction is quantitatively correct for 6.5 MeV protons.     

Wavelengths,transition probabilities,and oscillator strengths for M-shell transitions in Co-, Ni-, Cu-, Zn-, Ga-, Ge-, and Se-like Au ions

Wavelengths, transition probabilities, and oscillator strengths have been calculated for M-shell electric dipole transitions in Co-, Ni-, Cu-, Zn-, Ga-, Ge-, and Se-like Au ions. The fully relativistic multiconfiguration Dirac–Fock method, taking quantum electrodynamical effects and the Breit correction into account, was used in the calculations. Calculated energy levels of M-shell excited states for Cu-, Zn-, Ga-, Ge-, and Se-like Au ions from the method were compared with available theoretical and experimental results, and good agreement with them was achieved.     

Measurements of the total effective cross sections for resonance neutrons in Pd,Os, Ir,Mo, In,I, Ta,Th, U238

The results of calculations of the level constants in the elements Pd, Os, Ir, Mo, I, In, Ta, Th, U²³⁸ are presented; the cross sections for these elements have been published earlier. New measurements for the cross sections in Ir, Th, U²³⁸ are cited. The measurements were made with a mechanical-chopper spectrometer with a resolution of 0.08 sec/m in the energy region from 4.5 to 10,000 ev. The integrated and differential curves for the distribution of neutron widths in these elements are plotted.Presented at the International Conference on Nuclear Reactions in Amsterdam (June 1956).The authors take this opportunity to express their gratitude to U. Chi-Kwa and Suan Chi-Ling for their assistance in the mathematical analysis of the experimental results, G. M. Kukavadze for the mass-spectro-graphic analyses of the samples, V. N. Bovinoi and M. P. Anikinoi for providing the chemical analyses and A. I. Ermakov, N. S. Rezvyakov, G. V. Rukolaine and K. A. Trostinoi for help in building the analyzer and in carrying out the measurements.     

Discovery of dysprosium,holmium, erbium,thulium, and ytterbium isotopes

Currently, thirty-one dysprosium, thirty-two holmium, thirty-two erbium, thirty-three thulium, and thirty-one ytterbium isotopes have been observed and the discovery of these isotopes is described here. For each isotope a brief synopsis of the first refereed publication, including the production and identification method, is presented.