用于ADS启明星1#中子涨落特性测量的微电流放大器研制

通过对次临界反应堆中子噪声特性的分析,设计了一种能反映ADS系统启明星1#实验装置中子涨落特性的微电流放大器。通过设计和调试,该放大器能够实现10^-9－10^-11A的电流－电压通频带转换放大,达到了设计的要求。     

微弱电流的测量与I/F变换电路的设计

介绍了反馈式电流放大器型I／V转换和V／F变换电路的设计,详细讨论了减少噪声干扰的措施。可以测量10^-11～10^-6A的弱电流。     

弱电流测试仪的研制

介绍了最近研制的弱电流测试仪，它的原理和设计要点。该仪器是一 便携式弱电流测试仪，可以测量10^-10-10^-4A范围的弱小电流。该仪器具有测量精度高、工作稳定、结构简单、便携等优点。     

硫辛酸清除自由基的反应动力学研究

利用脉冲辐解和激光光解瞬态吸收光谱装置,研究了硫辛酸清除活性氧自由基（ROS）的反应机理,获得涉及反应的瞬态吸收光谱和反应速率常数,测得硫辛酸清除OH,eaq,CO3^-,SO4^-,Br2^-的反应速率常数分别为7．4×10^9、1．3×10^10、9．8×10^8、2．3×10^9、2．0×10^9L·mol^-1·s^-1,并对可能的反应机理进行了探讨。结果表明,硫辛酸能有效地清除活性氧自由基,是个高效的抗氧化剂。     

79Se—AMS测量样品的化学形式选择及其制备方法

中国原子能科学研究院的AMS小组在原蒋菘生、何明等对79Se—AMS测量的基础上,发展了基于SeO2-分子负离子引出形式的79Se—AMS测量方法,测量灵敏度由原来的3．0×10^-9提高到好于1．0×10^-12。     

聚变堆氚的环境安全评估

对国家863项目聚变实验增殖堆工程概要设计(FEB-E)进行了氚环境安全问题评估。FEB-E是采用液态锂作为包层氚增殖剂，每个包层模块各区之间用隔板隔开．中间通高压氦气冷却、包层第一壁和偏滤器也用氦气冷却。运用自行研制的SWITRIM程序和Sieverts’定律研究了正常工作状态下和事故状态下可能造成氚的环境污染水平。研究表明．正常工作状态下包层液态锂中的氚分压在10^-6～10^-8pa。造成氚环境污染的主要危险来自氚循环回路中的偏滤器子系统的抽出气体泄漏。因此，提高堆芯等离子体燃耗和真空系统设计性能是重要的。     

Nitrogen Fixation into HNO3 and HNO2 by Pulsed High Voltage Discharge

Plasma processing induced by discharge offers a unique way to activate nitrogen molecules. Direct nitrogen fixation into water can be realized through this approach. In this study, air or pure nitrogen gas was used as the major nitrogen source bubbled into the discharge reactor. When a discharge occurred, nitrogen was dissociated to active species to take part in the aqueous chemical process. HNO3 and HNO2 were produced. The nitrogen fixation process was influenced distinctly by the presence of hydroxyl radicals. During a discharge of 21 min, HNO3 was the main product and occupied 95% of the total nitrogen content in water. Its concentration was 1.36 × 10^-3 mol/L^-1 with bubbling air and was 1.53 × 10^-3 mol L^-1 with bubbling nitrogen, while the yield was 2.32 × 10^-3 mol J^-1S^-1 and 2.06 × 10^-8 mol J^-1S^-1, respectively.     

振动子式微电流直流放大器

为了提高直流放大器的稳定性,目前多采用变流的方法。变流装置中以振动子用得較多。无論在高輸入阻抗及低輸入阻抗的放大器中应用振动子变流都能获得較好的效果。我們对振子式高輸入阻抗直流放大器进行了一些研究,要求能測量的极限灵敏度达到10~(-12)安培。在本文中首先分析了国产振动子在高输入阻抗下各种干扰电压的来源、測試及其消除的方法。列举出整套直流放大器的試驗結果,基本上可达到10~(-12)安培的灵敏度,并指出适当改变输入回路的参数还可提高放大器的灵敏度,最后采用負反饋的方法来提高放大器的稳定度。     

变温法测量贮氢材料-氢系P-C-T曲线

描述了采用变温法测量室温下平衡压为10^-3～10^-5Pa量级、易于毒化的贮氢材料－氢系P－C－T曲线的测量原理、装置和具体测试步骤等，并通过测量贮氢材料－氢系P－C－T曲线检验了变温法的操作可行性，同时对变温法的特点和存在的问题进行了初步分析。     

重水堆1E级隔离放大器的研制及核电设备国产化的几点思考

针对在核电厂中大量进口设备和备件存在价格高、供货周期长、设计过时甚至存在设计缺陷等问题,本文以在秦山第三核电厂的专设安全系统中的隔离放大器为例,在分析隔离放大器的工作原理、工作方式等基础上,介绍了AGM隔离放大器的国产化研制流程和实际研制成果,包括隔离放大器设计缺陷的改进、加工和鉴定等过程管理,并分析了我国核安全相关控制设备的国产化现状、国产化意义,提出了针对核电设备和备件国产化的建议及展望。     

调节闪烁室法测量222Rn、220Rn时仪器工作状态对探测效率的影响

针对闪烁室法^222Rn、^220Rn的测量装置，介绍了一种调节仪器最佳工作状态的比较完善的方法，并用实验进行了探测效率比较。结果表明，通过调节闪烁室法测量此^222Rn、^220Rn浓度装置的工作状态，可以提高仪器的探测效率约10％。     

An Electrometer for Use in Scientific Space Instruments

A wide-range vibrating-reed electrometer that obtained extensive detailed data on the "solar wind" during the Mariner II flight to Venus is described. This circuit used an inverting carrier-type dc amplifier with a logarithmic diode as its principal feedback element and represented the first successful application of a space-qualified dynamic capacitor electrometer. This system also represents one of the earliest all-semiconductor amplifiers to be used in a dynamic capacitor electrometer. The wide dynamic range of the application (10-13 to 10-6 A) required the stabilization of a closed loop having 7 decades of continuous variation in the dynamic resistance of the primary feedback element. Some details of design, analysis, and performance associated with the electrometer amplifier and its feedback system are presented.     

锆铀合金中痕量硼的同位素稀释质谱法测定

本文介绍了用同位素稀释技术测定锆铀合金试样中痕量硼的方法。选用富集~(10)B为同位素稀释剂,用硫酸-硫酸铵溶样,使硼形成挥发的硼酸甲酯与基样分离,用热电离质谱仪进行硼的同位素比值测量。方法的检测下限为1.5ng(硼)。对于含硼量小于1.0μg/g(样)的锆铀合金试样,相对标准偏差小于±1.0%。     

压缩应力下石墨IG-110热膨胀系数的测量及验证

采用应变电测法测量压缩应力状态下石墨IG-110的热膨胀系数,分析不同压缩应力对IG-110热膨胀系数的影响.结果表明,压缩应力对IG-110的热膨胀系数影响显著.与未加载时相比,分别加载20、30、40 MPa压缩应力石墨试样平行加载方向的平均热膨胀系数由3.71×10~(-6) K~(-1)逐渐增大至4.20×10~(-6)、4.41×10~(-6)、4.78×10~(-6) K~(-1),分别提高约13.2%、18.9%和28.8%;而垂直加载方向的平均热膨胀系数则由4.03×10~(-6)K~(-1)逐渐减小至3.80×10~(-6)、3.79×10~(-6)、3.75×10~(-6)K~(-1),分别降低约5.7%、6.0%和6.9%.压缩应力状态下石墨热膨胀系数的变化可能与应力导致石墨内部微裂纹的张开和闭合有关.     

A novel digital neutron flux monitor for international thermonuclear experimental reactor

A novel full-digital real-time neutron flux monitor(NFM) has been developed for the International Thermonuclear Experimental Reactor.A measurement range of 10~9 counts per second is achieved with 3 different sensitive fission chambers.The Counting mode and Campbelling mode have been combined as a means to achieve higher measurement range.The system is based on high speed as well as parallel and pipeline processing of the field programmable gate array and has the ability to upload raw-data of analog-to-digital converter in real-time through the PXIe platform.With the advantages of the measurement range,real time performance and the ability of raw-data uploading,the digital NFM has been tested in HL-2 A experiments and reflected good experimental performance.     

Real-time wide-range neutron flux monitor for thorium-based molten salt reactor

A novel full-digital real-time neutron flux monitor(NFM) has been developed for thorium-based molten salt reactor(TMSR).The system is based on the highspeed,parallel,and pipeline processing of the field programmable gate array as well as the high-stability controller area network platform.A measurement range of 10~8 counts per second is achieved with a single fission chamber by utilizing the normalization of the count and Campbell algorithms.With the advantages of using the measurement range,system integrity,and real-time performance,digital NFM has been tested in the Xi'an pulsed reactor fission experiments and was found to exhibit superior experimental performance.     

基于三极管的CFBR-Ⅱ堆辐射损伤常数测定

为获取CFBR-II堆与其他装置建立辐射损伤等效系数的实验依据,在CFBR-II堆稳态工况下开展典型三极管的辐射损伤常数测定工作。结果表明,硅三极管的辐射损伤常数在4×10-16～6×10-16 cm2之间;对于直流增益与中子注量的线性关系的适用范围,集电极注入电流可以拓展到300 mA。     

Measurement of 79Se by accelerator mass spectrometry using projectile X-ray technique

1IntroductionInacceleratormassspectrometry(AMS)measurementsoflong-livedradioisotopes,stableisobarsarethedominantbackground.FortheradioisotopesofatomicnumberZ520,theisobarsbackgroundcanbeeliminatedbymeansofthedifferentenergylossofisobarinmatterduetotherateofenergylossisafunctionofZ.Butwithincreasingatomicnumber,theenergystragglingincreasesrelativetotheenergylossdifference,sothatisobarseparationbecomesprogressivelylesseffective.Inordertoseparatetheisobarswithhigheratomicnumberstheionenergyhast…     

Design and performance of a low-noise, low-power consumption CMOS charge amplifier for capacitive detectors

In this paper, a new design of low noise, low-power consumption charge amplifier is described. Theoretical results show that a total output noise voltage reduction of 0.261 mV has been obtained. This value corresponds to a 46% reduction compared to the noise performance of a conventional charge amplifier. A complete readout system including the proposed charge amplifier has been realized in a 0.8-/spl mu/m semiconductor on insulator (SOI) bipolar complementary metal-oxide-semiconductor (BiCMOS) process. A measured noise performance of 450 electrons at 0 pF with a slope of 44 electrons/pF for a shaping time of 45 ns, a conversion gain of 20 mV/fC and 1-mW power consumption have been obtained.     

Measurement and Research of Beam-Based Alignment With AC k-Modulation at HLS

A new beam-based alignment (BBA) measurement system with AC k-modulation module was developed recently at Hefei Light Source (HLS), which equipped the quadrupole magnets on the storage ring with a current shunt system which was able to vary the magnet current of a given quadrupole at a given frequency. The corresponding closed orbit oscillation amplitude measured for different beam positions in the quadrupole reached a minimum when the beam was centered in the quadrupole. Amplitude estimation algorithms of software lock-in amplifier and interpolated FFT were discussed. A V-shaped curve was used to determine the offset; a method using a parabola fit to determine the offset was also discussed. This BPM-to-quadrupole offset was determined at HLS with an accuracy of ~50 mum. The reproducibility of the beam based alignment using this technique is about 20 mum (RMS)