钡吸气剂和氩气

一、前言电真空器件的性能和寿命与管内气氛密切相关。管内的有害气体和杂质气体要减少到尽可能低的程度,因而选用各种类型的吸气剂来得到较为满意的真空气氛。钡吸气剂由于制造简单,价格低廉,吸气性能良好,在电真空器件中应用,管内真空度通常可提高1～2个数量级。可是,钡吸气剂蒸散后,因钡吸气剂会释放出一定量的氩     

非蒸散型锆-铝16合金消气剂的研制及在电真空工业中的应用

前言 消气剂是一种装在电真空器件内用来吸收管子封离后的残余气体,以及吸收管子工作时放出的气体的材料。它是电真空器件中的重要部件,对于提高管内真空度,延长寿命及高度可靠的工作起着重要的作用。 消气剂分为蒸散型和非蒸散型二种。蒸散型消气剂是利用蒸散或阴极真空喷镀而生成薄膜镜面用以吸附气体。属于这类消气剂的有Ba-Al,Ba-Ti,Ba-Mg,Ba-N,Ba—Al—Ni等。非蒸散型消气剂是一种容积消气剂,通过整个容积的化学吸附来吸收气体,使用时必须激活才能有效吸气。属于这类消气剂的有Zr—Al,Zr—Ti,Zr—C等合金。其中以Zr—Al合金应…     

一种供质谱仪器使用的小型超高真空系统

一 、引言 在一定的本底总压强中。质谱计能检测出某种气体的最低分压强的能力谓之浓度灵敏度。它表征仪器对气体混合物中所能测量的某一组分的最小量。在进行痕量质谱分析时,在浓度灵敏度不变的情况下,显然本底总压强越低,可检气体的最小量也越小,直至实现样品的超微量分析。在同位素稀释质谱法钾──氩地质年令测定中。为了测定年轻的中生代和新生代样品中的微量氩,传统的动态测量法由于其灵敏度低,耗样量大而显得无能为力。代之而起的是静态测量法,即将进入分析室内的微量氩样品在与外界隔绝的条件下进行质谱分析。 MS—10质谱计是英国…     

荧光灯管内气氛的定量分析

本文介绍了荧光灯管内气氛的分析装置、分析原理、分析步骤及分析结果。并对分析结果进行了数据处理和认真的讨论，最后得出了这样的结论：利用四极质谱计，对荧光灯管内气氛进行定量分析，从管内杂质气体浓度的大小，找出生产工艺之不足，为改进产品质量提供了可靠的依据．另外，对滴汞法和释汞吸气剂法生产的产品进行了比对，可知释汞吸气剂法生产的荧光灯管内杂质气体种类少、含气量低、质量高，同时也防止环境污染。它是荧光灯发展的方向。     

锆石墨消气剂激活时吸放气及其质谱分析

有色金属研究总院研制的YGS-1锆错石墨消气剂在室温具有吸收N_2、CO、H_2、H_2O、CH_4、O_2、CO_2等活性气体的能力,能有效提高电子管等真空器件的真空度。经同台测试证明,它对N_2,CO、H_2的吸气性能都超过了国外同类产品的水平。锆石墨消气剂在加热激活时会放出一定量的气体,但也吸收一定量的气体。我们对此特点进行了质谱分析。一、实验方法及装置实验采用静态定容法。整个装置是玻璃系统(如图1),主要由玻璃泡、四极质谱计探头、镓銦阀、B-A规和消气剂样品室等所组成。用GP3.5-E型高频感应加热设备加热消气剂样品。用铂铑-铂热电偶测量温度。消气剂的放气和残气由SJX-1型四极质谱计分析。     

非蒸散锆-铝16吸气剂及其应用

引言 为了获得长寿命,高可靠的电真空器件,近十五年来,对于新型吸气剂的研制和应用,已经越来越引起人们的重视,并且巳经取得了显著的成效。 实际上,吸气剂可以看成是组装在电真空器件内部的化学泵,其主要作用有以下几点: 1、在排气过程中,特别是在排气结束后的老炼过程中,吸收管子内部剩余的和重新释放的气体。 2、在电真空器件储存和工作期间维持一定的真空度。 3、吸收电真空器件启动和反常工作时爆发性的放气。应用于电真空器件的吸气剂,对它的主要要求是: (1)应该具有高的吸气能力和高的吸气速率,并能牢固地保持所吸的气体和蒸汽。 ( 2)…     

显像管残余气体分析及离子轰击研究

显像管中的残余气体是影响显像管质量和寿命的重要因素,通过四极质谱残余气体分析系统,可以对显像管中的残余气体进行有效的分析,对带消气剂的真空器件,本底要考虑扣除消气剂作用的影响.在此基础上可以进行残余气体离子轰击的计算机模拟研究,并对显像管电子枪进行优化设计.     

文摘索引

钡、锶和钙作为电子管中使用的吸气刘──《J.V.S.T.》Vol,14,№1 P636(1977) 钡和锶吸气剂有可能代替钡作为彩显管和其它电子管中的气体吸着体用。将钙铝或锶铝合金磨成粉末,并与镍粉相混和,然后压入到不锈钢环形槽内,即制成在空气中性能稳定的吸气剂。显象管经排气并封离之后,通过加热吸气剂,将锶或钙蒸散到显象管的内表面,以沉积一层能吸着气体的薄膜。用氧气吸着试验法来测定锶和钙吸气剂的性能,并同彩易管中的钡吸气剂作了比较。这种氧气吸着试验法可以鉴定在没有危及电子管氧化物阴极之前,吸气膜对氧气的最大吸着量。试验表明,蒸散…     

光干涉型甲烷测定器的正确使用与维修

一、使用前的准备工作 1.装药,首先将氯化钙或硅胶、纳石灰等药品装入吸收管内。药品颗粒大小以（3～5）mm为宜。 2.对各气路部分进行“堵、漏”检查。先检查吸气球是否漏气。检查的方法：用一手压出球内气体,另一手压住球上的橡皮管,如球不立即膨胀还原,就说明不漏气。     

质谱定量分析方法的探讨及应用研究

建立了一套在气样室内气样压强低于700Pa时均可满足“分子流进样”条件的质谱校准与定量分析系统。通过大量的实验，确定了四极质谱计的工作参数；测定了常用被分析气体的定量系数；并采用实时校准的办法，利用标准气样标定了本装置的系统误差；对各类荧光灯中混合型填充气体的配比和国内外成品荧光灯中的杂质气体含量进行了质谱定量分析；测定了生产中未充入填充气体的灯管内的残气压强。取得了一批对指导生产、改进工艺有用的数据。本系统同样也适用于其他类似场合。     

New high capacity getter for vacuum insulated mobile LH2 storage tank systems

Current “Non-evaporable getters” (NEGs) are important for the improvement of vacuum by the help of metallic surface sorption of residual gas molecules. High porosity alloys or powder mixtures of Zr, Ti, Al, V, Fe and other metals are the base material for this kind of gas sorbents. The development of vacuum technologies creates new challenges for the field of getter materials. The main sorption parameters of the current NEGs, namely, pumping speed and sorption capacity, have reached certain level limits. Chemically active metals are the basis of NEGs of a new generation. The appearance of new materials with high sorption capacity at room temperature is a long-felt need. It is obvious, that chemically active metals and alloys with reactivity higher, than that of transition metals, can become this kind of materials. The potential of active metals as the strongest gas sorbents is very high. The improved getter materials allow faster pumping speed. The sticking rate on the chemically active surface is significantly higher, and sorption capacity can be increased by up to 104 times (during the life-time of a device the entire getter material reacts with residual gases). The main structural form of the new getter concepts are spherical powders, granules and porous multi-layers. The full pumping performance takes already place at room temperature and the activation temperature can be adjusted between room temperature and 660 °C. The successful insertion of this new chemical getter pump in a mobile double-walled LH₂ tank system shows the very high sorption capacity of all relevant residual gases including H₂. This new invention opens the possibility for significant vacuum improvements especially in the field of H₂ pumping, which is an important challenge in many different vacuum devices and processes.     

被动型氢原子钟吸气剂泵的应用研究

描述了上海天文台在2008年为提高被动型氢原子钟真空系统的可靠性所研制的由非蒸散型吸气剂泵和小离子泵组成的复合泵的实验过程,吸气剂泵在室温下吸收2.1MPa.l的H2气后仍可达到3.2×10-5Pa的真空度,2l/s的离子泵电流工作在0.30μA,证明了复合泵可以维持氢钟13年以上的正常工作。经过再激活固定了激活工艺,吸气剂最终吸氢6.0 MPa.l仍没有饱和,证明了吸气剂的强大吸氢能力。至今复合泵已成功应用在4台被动型氢钟上。     

新型吸气剂泵真空测试系统的搭建与实验研究

烧结型非蒸散吸气剂泵HV800(意大利SAES公司生产)具有抽速大、抽气容量高、安装维护简单等优点,可能适用于EAST托卡马克偏滤器抽气,提高该区域粒子排出能力。本文搭建了一套极限真空5.1×10^-7Pa、具备抽速定量标定的真空测试系统,对HV800开展了对氘气抽速的标定实验。研究结果表明在偏滤器工作气压下,平均抽速可达240 L/s。经评估HV800应用于EAST的初步方案,偏滤器区域会增加5×10⁴L/s抽速,并可连续运行20 h以上,是有效提高EAST偏滤器粒子排出能力的可行选择。     

Apparent and real values of common gas sticking coefficients on titanium films and application to getter pump devices with periodic active film renovation

The getter pump design needs reliable values of the sticking coefficient of the pumped gas as well as their change during the getter film saturation. The paper deals with averaging of known experimental data for sticking coefficients of common gases on titanium films, taking into account their roughness. The kinetics of N₂ and H₂ sticking coefficients at different pressures is also given, which makes possible the design of getter pump devices with periodic active film renovation.     

非蒸散型吸气剂在微型离子泵中的应用

为确保小尺寸超高真空密封器件的高可靠和长寿命,开发了一种带非蒸散型吸气剂的微型复合离子泵(Mini-Combination Ion Pumps with NEG).在新建的微型离子泵性能测试系统上,研究了非蒸散型吸气剂对器件存储和微型离子泵启动特性的影响.模拟了微型离子泵与小型真空器件集成为一体时可能遇到不同气体负载时的实际情况,讨论了新结果的可能应用.     

可低温激活的钛锆钒非蒸散型吸气剂薄膜的制备及其性能研究

非蒸散型吸气剂材料是近年来广泛应用于真空领域的一种重要材料,但过高的活化温度限制了它的应用场景。本文使用比例均匀一致的钛锆钒合金作为靶材,经直流磁控溅射沉积了活化性能良好的非蒸散型吸气剂薄膜,使用X射线光电子能谱对薄膜的表面化学状态进行了分析。结果表明随着加热温度的升高薄膜表面成分呈现高氧化态-低氧化态-金属态的变化规律,该薄膜在150℃下加热后开始发生明显活化,并且在温度升高后活化程度进一步增高。薄膜在激活后具有良好的吸气性能,且薄膜的长时间使用具有可靠的稳定性。     

Applications of non evaporable getter pump in vacuum metrology

Applications of non evaporable getter pump in vacuum metrology are reviewed and discussed with a special focus on static expansion primary vacuum standard, and flow division method ultra-high vacuum (UHV) and extremely high vacuum (XHV) standard. The results obtained show that the non evaporable getter pump is suited for extending the calibration lower limit, and it is a valuable supplement to the basic methods. The feasibility of use of non evaporable getter pump in constant conductance method vacuum leak standard is also discussed.     

Experimental investigation on hydrogen adsorption performance of composite adsorbent in the tank with high vacuum multilayer insulation

Hydrogen is one of the main residual gases in the high vacuum multilayer insulated tank. H₂ adsorption performance of the composite adsorbent was investigated by using a test bench, an X-ray diffraction and a scanning electron microscopy.The composite adsorbent is composed of molecular sieve 5A and getter that includes the different proportion of PdO and Ag₂O. The getter shall is laid as flat as possible when fed into the tank. Leakage and outgassing rate can be decreased by 64% after placing getter. The crystal phase structure of PdO and Ag₂O in getter is unchanged by adsorption performance. Experimental results showed that the H₂ adsorption rate is high at the initial stage, and then it starts to become slow during a relatively long period. The type IV isotherms were obtained with these samples, and the H₂ adsorption principle is also discussed. The optimum percentage content of Ag₂O in the getter is 22%. Under the allowed highest pressure, the composite adsorbent that includes 15% Ag₂O, 85% PdO and molecular sieve 5A is preferentially used in the tank interlayer. The experimental results and performance analyses can be used in the design of the high vacuum multilayer insulated tank.     

A new generation of getter‐coated sputter ion pumps for XHV applications

A new concept of sputtered ion getter pump is presented. The body of this pump is internally coated by a getter thin film constituted by a layer of TiZrV together with a protective covering of palladium, according to a technology that CERN (European Center for Nuclear Research) licensed us. TiZrV is a well‐known alloy able to pump getterable gases such as hydrogen, oxygen, nitrogen, carbon monoxide and dioxide. With the exception of H², the sorption of these gases is not reversible and it causes a progressive contamination of the bulk of the material. With the addition of the palladium overlayer, the pumping action is limited to hydrogen and carbon monoxide, but the lifetime of the film is strongly enhanced, thanks to the possibility of an unlimited number of thermal activations, which restore the initial performances of the film. An innovative sputter ion pump design, optimized for both pumping speed in ultra high vacuum and getter film sputtering, will be introduced. Moreover, pumping speed measurements and ultimate pressure data, obtained after a relatively short bake‐out at temperature lower than standard procedures, will be reported.     

Operational experience and relation to deposition process for NEG-coated chambers installed on the ESRF electron storage ring

A majority of the ESRF insertion device sections have been equipped with NEG-coated low gap vacuum chambers made of extruded aluminium and PVD coated with a low-temperature non-evaporable getter coating at ESRF. The low initial outgassing and quick conditioning allowed some modifications for chamber installation and accelerator restart procedures. The operational behaviour of those chambers has been studied not only by means of vacuum gauges but also with ionisation chambers measuring the bremsstrahlung sent to the connected synchrotron beamlines. The NEG-coating film thickness was optimised taking into account vacuum performance and also coating process parameters and duration. The 2nd more flexible and powerful NEG-coating device is under commissioning in the NEG-coating facility at ESRF.