著者
木本 雄吾 宮崎 英治 石澤 淳一郎 島村 宏之
出版者
一般社団法人 日本真空学会
雑誌
Journal of the Vacuum Society of Japan (ISSN:18822398)
巻号頁・発行日
vol.52, no.9, pp.475-483, 2009 (Released:2009-10-29)
参考文献数
50
被引用文献数
6 7

The current issues of atomic oxygen (AO) effects on space materials in low earth orbit and its ground evaluation techniques are described briefly. AO is the dominant gas component at altitudes of 200-600 km. It has abundant energy to break hydrocarbon polymer bonds, thereby causing oxidation and thinning of the polymers through loss of volatile oxidation products. Therefore, ground evaluation of space materials is important. The AO source in Japan Aerospace Exploration Agency (JAXA) is based on laser breakdown phenomena. This source is one of the combined space effects test facility, which accommodates the irradiation of independent or coincidental electron beams, ultraviolet rays, and AO. Evaluation of common space materials has been done in addition to researches into new AO protective coatings and materials.   As described herein, the AO environment, its interactions with materials, results of space experiments, ground laboratory simulation techniques, and mitigation techniques are presented.
著者
松田 七美男
出版者
一般社団法人 日本真空学会
雑誌
Journal of the Vacuum Society of Japan (ISSN:18822398)
巻号頁・発行日
vol.56, no.6, pp.199-203, 2013 (Released:2013-06-28)
参考文献数
7
被引用文献数
3

To understand the property of gases, it is essential to consider them using kinetic theory of gases. This theory assumes that gas atoms/molecules are freely travelling and frequently changing their speed and direction by collisions each other. The purpose of the present article is to try to introduce the basic concepts of kinetic theory of gases to readers. We also show how it explains the fundamentals of vacuum science such as idealgas laws, origin of pressure, surface impinging rate and mean free path.
著者
岡本 幸雄
出版者
一般社団法人 日本真空学会
雑誌
Journal of the Vacuum Society of Japan (ISSN:18822398)
巻号頁・発行日
vol.59, no.7, pp.161-170, 2016 (Released:2016-07-16)
参考文献数
11
被引用文献数
1

プラズマを用いた微細加工や成膜などのプラズマプロセスにおけるプラズマの基礎的な事項(プラズマの性質と基礎量,プラズマ中の素過程,荷電粒子の消滅過程,イオンシースの形成と性質,主なプラズマの生成原理と基本的な特性および電子温度の制御法など)について解説した.
著者
藤井 治久
出版者
一般社団法人 日本真空学会
雑誌
Journal of the Vacuum Society of Japan (ISSN:18822398)
巻号頁・発行日
vol.56, no.12, pp.493-501, 2013 (Released:2013-12-27)
参考文献数
33

It is well known that spacecrafts on orbits are charged up due to the interaction with space plasma and high energy charged particles. Those charging phenomena are categorized into two. One is “surface charging” and the other is “internal charging”. The surface charging involves absolute charging of the conductive satellite body and differential charging occurring on different surface materials on the satellite. On the other hand, the internal charging occurs on the insulating materials and/or electrically floating conductors installed inside the spacecraft body. When the level of the differential charging and/or internal charging reaches some threshold, ESD's (Electrostatic Discharges) will possibly occur. The author reviewed these ESD phenomena based on the ground experiments simulating space environments.
著者
國貞 雄治
出版者
一般社団法人 日本真空学会
雑誌
Journal of the Vacuum Society of Japan (ISSN:18822398)
巻号頁・発行日
vol.60, no.7, pp.249-255, 2017 (Released:2017-07-15)
参考文献数
47
被引用文献数
1

We theoretically investigated physisorption on ice Ih and ice XI surfaces, because the physisorption states of adsorbates play important roles in the chemical reaction on the interstellar medium, which generally consists of ice, with the extremely low temperature (10 K) condition. In this paper, we focused on hydrogen molecules as adsorbates because hydrogen is the most abundant element in space. At first, we briefly reviewed the way to treat the van der Waals interaction in density functional theory. We also showed the calculated adsorption states of hydrogen molecules on ice Ih and ice XI surfaces. We found the non-local correlation functional, which can treat the dispersion interaction, improved the potential energies of physisorbed hydrogen molecules on ice Ih and ice XI surfaces.
著者
黒河 明 北條 久男 小林 太吉
出版者
一般社団法人 日本真空学会
雑誌
Journal of the Vacuum Society of Japan (ISSN:18822398)
巻号頁・発行日
vol.54, no.3, pp.196-198, 2011 (Released:2011-05-17)
参考文献数
7
被引用文献数
1

The vibrating quartz oscillator in the viscous-flow gas was observed to compare the pressure (P) dependence between the impedance change (ΔZ) and the frequency change (ΔF). We obtained the ΔZ and the ΔF for Ar, O2, and Ne gases. Among Ar and O2 both the ΔZs and the ΔFs had no intersection with each other. However, Ne gas had the intersections with Ar gas with the ΔZ(P) and with O2 for the ΔF(P). The phenomenon was caused by the Ne property which Ne has smaller mass but larger viscosity compared with Ar and O2. The ΔZ-ΔF property showed that the property of each gas lied in the viscosity descending order, i.e., Ne, Ar, O2. The measurement of (ΔZ, ΔF) property could give the viscosity related information.
著者
泉 富士夫 門馬 綱一
出版者
一般社団法人 日本真空学会
雑誌
Journal of the Vacuum Society of Japan (ISSN:18822398)
巻号頁・発行日
vol.53, no.12, pp.706-712, 2010 (Released:2011-01-20)
参考文献数
26
被引用文献数
2

We have been developing a multi-purpose pattern-fitting system RIETAN-FP and a three-dimensional visualization system VENUS, which have been extensively used for structure refinements of various metal and inorganic materials from neutron powder diffraction data. At first, their outlines and the history of their developments are shortly looked back. The second part describes procedures for analyzing collinear magnetic structures with the combination of VESTA in the VENUS system and RIETAN-FP by taking BiCoO3 for instance. Finally, a new C++ program, Dysnomia, for the maximum entropy method is introduced with emphasis on its new features. Dysnomia excels its predecessor, PRIMA, in computation speed, memory efficiency, scalability, and reliability. In particular, addition of a normal-distribution constraint is effective in obtaining nuclear-density distribution that is physically and chemically reasonable.
著者
黒河 明
出版者
一般社団法人 日本真空学会
雑誌
Journal of the Vacuum Society of Japan (ISSN:18822398)
巻号頁・発行日
vol.56, no.8, pp.307-314, 2013 (Released:2013-08-27)
参考文献数
61
被引用文献数
1 1

Surface-treatment methods using ozone, such ozone gas treatment with UV light irradiation, immersion in ozone diluted water, and exposure to ozone gas are discussed herein. The objectives of performing ozone surface treatments are to reduce carbon-related contamination on the surface, prepare a clean substrate surface to fabricate a thin-film stacking with sharp interfaces, oxidize a surface to form high-quality oxide thin films, and passivate a metal surface to increase its corrosion resistance. These objectives are achieved because of the high oxidation ability of the ozone molecules and the oxygen radicals resulting from the ozone dissociation. Various applications of ozone surface treatment are also exemplified in this report to reveal their significant potential as surface-treatment tools.
著者
市村 正也
出版者
一般社団法人 日本真空学会
雑誌
Journal of the Vacuum Society of Japan (ISSN:18822398)
巻号頁・発行日
vol.58, no.8, pp.273-281, 2015 (Released:2015-09-04)
参考文献数
5

The purpose of this article is to provide an introduction to vacuum science and technology for absolute beginners. The kinetic theory of gases is briefly described in the initial introductory part. The body of this article is divided into three parts. The first part deals with vacuum pumps. The operation principles are explained for several popular types of vacuum pumps. The second part deals with vacuum gauges. The operations of commonly used vacuum gauges are discussed. The third one deals with vacuum-tight connection with tubes and flanges. Throughout the text, basic concepts and technical terms are explained so that the text can be easily understood even by very beginners. Caution points for using vacuum systems are also given.
著者
田村 和宏 大熊 春夫 高野 史郎 正木 満博 持箸 晃
出版者
一般社団法人 日本真空学会
雑誌
Journal of the Vacuum Society of Japan (ISSN:18822398)
巻号頁・発行日
vol.54, no.3, pp.155-157, 2011 (Released:2011-05-17)
参考文献数
2

Radiation shields are required in beamlines (BL) that transport synchrotron radiation (SR) to stop high energy radiation that is scattered by instruments upstream of a BL. Radiation shields guarantee radiation safety in the downstream of the BL and need to be installed in the vacuum system of the BL. In order to limit the opening against unnecessary scattered radiation and to keep the effective aperture for SR as large as possible, a new type of radiation shield, which utilizes tungsten alloy with an opening as an ultra-high vacuum chamber, has been developed.
著者
小倉 正平
出版者
一般社団法人 日本真空学会
雑誌
Journal of the Vacuum Society of Japan (ISSN:18822398)
巻号頁・発行日
vol.57, no.6, pp.219-226, 2014 (Released:2014-06-25)
参考文献数
40

Thermal desorption spectroscopy (TDS) is an important technique for investigation of adsorption, absorption, and desorption behaviors of atoms and molecules on surfaces. We briefly summarize the general procedure of TDS in surface science studies, and then we introduce our recent study of hydrogen transport across a Pd-Au alloy surface measured by TDS as an example. By combining the TDS data with other surface analysis, we found that hydrogen penetrates and desorbs through a site related to surface Pd atoms. We also demonstrate a molecular cap effect of CO, where a small amount of CO adsorption greatly changes the hydrogen absorption and desorption behavior by blocking the entrance and exit site.
著者
上原 洋一 潮田 資勝
出版者
一般社団法人 日本真空学会
雑誌
Journal of the Vacuum Society of Japan (ISSN:18822398)
巻号頁・発行日
vol.51, no.12, pp.796-800, 2008 (Released:2009-01-15)
参考文献数
21

Scanning tunneling microscope (STM) light emission spectroscopy provides a powerful tool for characterization of individual nanometer scale structures on solid surfaces. However, the light to be detected is usually very weak. It is desirable to improve the intensity level for measurements with good signal-to-noise ratio. For this purpose the role that the STM tip-sample gap plays in the light emission is analyzed by the dielectric theory of STM light emission. Based on the theoretical predictions, we discuss how one can obtain strong STM light emission and problems associated with the enhancement of emission.
著者
齊藤 芳男 高橋 竜太郎
出版者
一般社団法人 日本真空学会
雑誌
Journal of the Vacuum Society of Japan (ISSN:18822398)
巻号頁・発行日
vol.54, no.12, pp.621-626, 2011 (Released:2012-01-12)
参考文献数
10
被引用文献数
2 2

The LCGT (Large-scale Cryogenic Gravitational wave Telescope) is an interferometer of 3-km long baseline, using a laser beam of 1064-nm wavelength. The entire system of the interferometer is to be operated in a vacuum for avoiding any noises caused by in-space molecules and adsorbed molecules on the mirrors. The beam tubes of 3 km long and 800 mm in diameter are to be kept in the order of 10−7 Pa so as to reduce scattering-effects due to residual gas molecules. In April 2011, production of 484 of unit tubes of 12 m long and 800 mm in diameter, having a flexible bellows and flanges, were started. In this report, the production process of the unit tubes is described concerning surface treatment for outgas reduction.
著者
柳内 克昭 平田 京 石田 洋一
出版者
一般社団法人 日本真空学会
雑誌
Journal of the Vacuum Society of Japan (ISSN:18822398)
巻号頁・発行日
vol.55, no.5, pp.220-225, 2012 (Released:2012-06-20)
参考文献数
26

With the increase in the recording density of hard disk drives, the narrower magnetic pole and read-sensor widths in writing and reading heads are required, and techniques used for the magnetic behavior analysis in a nanoscale area is essential. The observation of the in-plane domain structure of the writer pole for a perpendicular recording (PMR) head was performed by electron holography in order to elucidate the mechanism of the pole erasure originating from the instability of the magnetic domain state. The results revealed that the stability of the domain structure is strongly related to the domain wall trapping, and the pole erasure can be suppressed by realizing the stable domain structures. With respect to a current perpendicular to plane (CPP)-giant magneto-resistive (GMR) head, which has been promising candidates of a next-generation reading head element, the insertion of non-magnetic materials, such as Cu, between the ferromagnetic pinned and free layers is known to increase the MR ratio. For realizing the practical use of the CPP-GMR head, effects of the insertion of materials on the increase in the MR ratio were investigated by X-ray magnetic circular dichroism (XMCD). The results revealed that XMCD is a powerful technique to obtain information on electronic states and magnetic moments with the help of the theoretical electronic band calculation. The potential application of secondary cantilever resonance magnetic force microscopy and spin-polarized scanning electron microscope to the in-situ magnetic imaging of PMR heads will be also discussed.