这项工作得到了 nasa/SSERVI 建模等离子体、大气层和宇宙尘埃 (撞击) 和 nasa 太阳能系统工作计划 (赠款号: NNX16AO81G) 的支持。

1. 真空室设置
<ol><li>将绝缘橡胶板 (直径为0.2 厘米, 5 厘米) 与一个中心孔1.9 厘米直径在绝缘板上 (2 厘米厚和20厘米直径) (图 2a, b)。负载绝缘, 不规则形状的尘埃粒子 (直径在10和50微米之间) 在洞中。</li>
	<li>将绝缘板放置在真空室中间的金属板上。用陶瓷支架将金属板从腔室中电隔离。</li>
	<li>打开真空泵 (由机械粗加工泵支持的涡轮泵), 以达到 10-6乇的基本压力。演示实验是在圆柱形不锈钢真空室, 直径50厘米和28厘米高 (图 2c) 中进行的。</li>
	<li>用摄像机以30帧/秒 (fps) 或高速 (> 2000 fps) 相机的速度记录尘埃运动和放样。使用 LED 灯的最大照明相当于 > 500W incandesce 光, 以产生足够的照明粉尘颗粒, 以高质量的视频记录。 注: 使用橡胶是因为它的深色, 最大限度地减少光反射到相机。浅色粉尘颗粒应用于更好的拍摄, 因为颜色对比的黑色橡胶表面。该厚绝缘板用于消除绝缘板表面与金属板之间的电场对粉尘充电和动员的影响。在这个示范, 火星模拟 (JSC-Mars-1, 筛到平均直径38-48 微米, 质量密度为1.9 克/厘米-3和主要组成的, 即2 28) 使用, 这类似于一般的壤粉尘的无气体在内部太阳系。还测试了各种其他类型的绝缘尘埃粒子, 如月球模拟 (JSC-1)、月球模拟高地 (LHT) 和纯二氧化硅粉尘。</li>
</ol>2. 与电子束电子接触热等离子体
<ol><li>将钍钨长丝 (0.1 毫米厚和3厘米长) 连接至电极馈并安装在燃烧室的顶部。然后将腔体泵入基压。</li>
	<li>用氩气将真空室填充到 0.5 mTorr 的压力。</li>
	<li>打开电源并将偏置电压设置为灯丝的-120 V。</li>
	<li>增加加热电流的发热电压为 2A, 直到发射电流达到所需值 (少量 mA)。能量为 120 eV 的电子将从灯丝中发出。 注意: 这些光束状的初级电子会影响中性氩原子, 导致它们被电离, 并产生一个电子温度约 2 eV 的等离子体。一大小部分的主光束电子直接到达尘土飞扬的表面, 而不会与中性原子发生碰撞。尘埃粒子因此暴露在热等离子体和电子束电子。</li>
	<li>为了显示高能束电子在尘埃传输中的作用, 在尘埃粒子上使用一种可替代的方法来创建热等离子体。<ol>
<li>打开房间底部的备用灯丝, 其偏置电压为-40 伏, 排放电流高达400毫安 (图 2a)。从灯丝发出的主要电子将被金属板阻挡在灰尘颗粒休息的侮辱板上 (图 2a, b)。</li>
		<li>变化的发射电流, 以改变表面上的电场。更高的电流产生更高的等离子密度, 更薄的鞘, 因而更大的电场。</li>
	</ol>
</li>
</ol>3. 只接触电子束电子
<ol><li>在上面的实验中, 用上面的灯丝来设置实验。</li>
	<li>在基压 10-6乇 (i. e) 下打开顶丝, 在会议厅中没有氩气。没有等离子被创造, 而只有 120 eV 光束电子发出的灯丝轰击尘埃粒子。</li>
	<li>用两种不同的模式操作灯丝。<ol>
<li>将偏置电压设置为-120 伏, 然后增加加热电压直至发射电流达到数毫安。</li>
		<li>增加加热电压达到所需的加热电流 ~ 2 a, 然后将偏压从0伏逐渐增加到-120 伏, 以少量 mA 的发射电流发射电子。</li>
	</ol>
</li>
</ol>4. 只接触紫外线辐射
<ol><li>用 UV 灯 (图 2b) 替换顶部灯丝, 并将该腔体向下泵入底座压力。使用氙准分子欧司朗灯, 它发出 172 nm 波长的紫外线光。相应的光子能是 7.2 eV, 大于灰尘表面的工作功能 (~ 5.5 eV) 为了发射光电子。 注: 辐射更高能量光子的波长较短的紫外线, 预计会在尘埃粒子上产生更多的电荷, 因此可以根据修补后的电荷模型26,27来增加更多的动员。</li>
	<li>打开紫外线灯辐射尘埃粒子。在演示中, 光子辐照度是40兆瓦/厘米-2在紫外线源和 ~ 16 兆瓦/cm-2在尘土飞扬的表面。</li>
</ol>

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作者没有什么可透露的。

数十年来, 静电尘埃在无气物体壤上的传输问题仍然是一个悬而未决的问题, 如何壤尘埃粒子获得足够大的电荷来动员或放样。最近的实验室研究26,27从根本上提高了对这个问题的理解。
在这里, 它被证明三最近开发的实验显示粉尘充电和动员在热等离子体与电子束电子, 仅电子束或紫外线辐射。这些实验的关键元素是创造二次电子?...

无空气的行星体, 如月球和小行星, 被称为壤的细小尘埃粒子所覆盖。这些空气不通风的物体, 不像地球, 直接暴露于太阳风等离子体和太阳紫外线 (UV) 辐射, 导致壤尘埃被充电。因此, 这些带电的尘埃粒子可能会被动员, 放样, 运输, 甚至从表面上被逐出和丢失由于静电力量。这一静电过程的第一个建议证据是所谓的 "月球地平线辉光", 在日落后不久观察到的西部地平线上的一个明显的辉光, 由测量员 5, 6, 7 航天器五年前 (图 1a)1, 2,3。据推测, 这一辉光是由从静电放样尘埃粒子 (5 微米半径) 到高度 < 1 米以上的距离月球终结器1,2,3。静电释放的细粉尘也被建议负责的射线状的彩带达到高海拔的阿波罗宇航员4,5。
自从这些阿波罗观测, 许多对其他无气物体的观测也与静电尘埃的动员或放样机制联系在一起, 例如土星环中的径向辐条6,7,8, 在小行星爱神 (图 1b)9和彗星 67P10上的尘埃池, 从主带小行星谱11的多孔表面, 土星冰冷的月球地图集12的异常平滑表面, 以及壤在月球漩涡13。此外, 激光反光境在月球表面的退化也可能是由静电放样尘埃的积累引起的 14.
实验室研究的主要动机是这些不寻常的空间观测, 以了解粉尘充电和运输的物理过程。在各种等离子体条件下观察到粉尘的动员, 其中尘埃粒子从玻璃球表面脱落15,16, 在等离子鞘中悬浮17, 并记录在导电和绝缘上移动。表面18,19,20,21。然而, 尘埃粒子如何获得足够大的电荷来放样或动员仍然是很不清楚的。对光滑表面上单个尘埃粒子的电荷的测量22和在尘埃表面上的平均电荷密度23浸入等离子显示, 这些电荷太小, 不能放样或动员尘埃粒子。
在前面的理论16,24,25中, 充电只被认为发生在直接暴露于紫外线或等离子的顶面层上。电荷通常被认为是均匀分布在整个尘土飞扬的表面上, i. e., 每个单独的尘埃粒子获得相同的电荷量, 由所谓的 "共享电荷模型"16描述。然而, 从这个模型计算的电荷比单独的引力要小得多。电荷涨落理论, 将电子和离子通量的随机过程解释为表面的16,24显示了静电力的时间增强, 但相对于引力。
本文利用三新近研制的实验26对静电粉尘的放样和动员进行了论证, 对了解无气行星体壤的粉尘输送具有重要意义。这些实验是在热等离子体的条件下, 电子束电子, 仅电子束或紫外线辐射。这些实验证明了最近开发的 "修补电荷模型"26,27的有效性, 其中微腔在表面下面的相邻尘埃粒子之间形成, 可以重新吸收发出的照片和/或二次电子, 在相邻的尘埃粒子的表面产生大的负电荷。这些负电荷之间的排斥力可以变得足够大, 以动员或解除尘埃粒子。

<table><tbody><tr><td>Vacuum chamber</td><td>Any</td><td>NA</td><td></td></tr><tr><td>Vacuum electrode feedthrough</td><td>Lesker</td><td>EFT0113053</td><td></td></tr><tr><td>Tungsten filament (0.1 mm thick)</td><td>Goodfellow</td><td>W055250</td><td>Thoriated</td></tr><tr><td>Power supply #1 (0-8V, 3A)</td><td>Agilent</td><td>E3610A</td><td>Or equivalent</td></tr><tr><td>Power supply #2 (0-140V, 0.5A)</td><td>Agilent</td><td>E3612A</td><td>Or equivalent</td></tr><tr><td>UV lamp</td><td>Osram</td><td>XERADEX L40/120/SB-SX48/KF50HV</td><td>Or equivalent</td></tr><tr><td>Dust sample</td><td>Any</td><td>Mars or Lunar simulants or other types</td><td>Irregularly-shaped, sieved, insulating</td></tr><tr><td>Insulating plate</td><td>Any</td><td>NA</td><td>Thickness &gt; 1 cm</td></tr><tr><td>Rubber sheet</td><td>Any</td><td>NA</td><td>Thickness &gt; 1 mm</td></tr><tr><td>Metal plate</td><td>Any</td><td>NA</td><td></td></tr><tr><td>Ceramic stands</td><td>McMaster</td><td>94335A130</td><td>1/2&quot; diameter</td></tr><tr><td>Video camera (consumer)</td><td>Panasonic</td><td>HC-VX870</td><td>Or equivalent</td></tr><tr><td>Video camera (high-speed)</td><td>Phantom</td><td>V2512</td><td>&gt; 1000 fps</td></tr><tr><td>LED lamp</td><td>Any</td><td>NA</td><td>&gt; 500W Tungsten Equivalent</td></tr></tbody></table>

experimental methods of dust charging and mobilization on surfaces with exposure to ultraviolet radiation or plasmas

静电尘埃的传输已经被推测来解释一些异常行星现象的观测。在这里, 它被证明使用三最近开发的实验中, 尘埃粒子暴露在热等离子体与电子束电子, 只电子束, 或紫外线 (紫外线) 辐射。紫外线光源的波长以 172 nm 为中心, 带宽狭窄。光束电子与能量的 120 eV 是创建一个负偏热灯丝。当真空室充满氩气时, 除了电子束外, 还会产生热等离子体。实验中使用了直径几微米的绝缘粉尘微粒。尘埃粒子被记录为放样的高度, 最高可达几厘米, 发射速度可达1米/秒。这些实验表明, 灰尘表面的照片和/或二次电子发射改变了尘埃粒子的充电机制。根据最近开发的 "修补电荷模型", 发射的电子可以在微腔内的相邻尘埃粒子之间重新吸收, 从而导致周围尘埃的增强负电荷堆积。粒子.这些负电荷粒子之间的排斥力可能足够大, 可以动员并将它们从表面上提起。这些实验对尘土飞扬的表面进行了粉尘充放电和运输的深入认识, 为今后研究其在无气行星体表面演化中的作用打下了基础。

用顶部或底部的细丝进行了一系列实验。使用顶部灯丝设置, 记录了尘埃粒子的跳跃 (图 3a)。相比之下, 当使用底部灯丝时, 尘埃颗粒仍保持静止。测量了在协议步骤 226中描述的条件下, 在两个实验中, 表面的垂直电场近似相同 (16 伏/厘米)。这些结果表明, 由于鞘电场的静电力不够大, 无法调动粉尘颗粒。这两个实验的唯一区别是存在...

Watch this Scientific Journal Video about Experimental Methods of Dust Charging and Mobilization on Surfaces with Exposure to Ultraviolet Radiation or Plasmas at JoVE.com

Experimental Methods of Dust Charging and Mobilization on Surfaces with Exposure to Ultraviolet Radiation or Plasmas

在三实验中, 用电子束电子、电子束或紫外线 (UV) 辐射照射热等离子体, 证明了粉尘的充电和动员。这些实验对静电粉尘的传输及其在无气行星体表面成形中的作用提出了先进的认识。

紫外辐射或等离子体照射表面的粉尘充电和动员实验方法

Electrostatic dust transport has been hypothesized to explain a number of observations of unusual planetary phenomena. Here, it is demonstrated using ...

experimental-methods-dust-charging-mobilization-on-surfaces-with

Universidad San Sebastian

Research

JoVE Journal

Environment

8.1K 次观看.  University of Colorado. 在三实验中, 用电子束电子、电子束或紫外线 (UV) 辐射照射热等离子体, 证明了粉尘的充电和动员。这些实验对静电粉尘的传输及其在无气行星体表面成形中的作用提出了先进的认识。

视频: Experimental Methods of Dust Charging and Mobilization on Surfaces with Exposure to Ultraviolet Radiation or Plasmas

Encapsulation and Permeability Characteristics of Plasma Polymerized Hollow Particles

In this protocol, core-shell nanostructures are synthesized by plasma enhanced chemical vapor deposition. We produce an amorphous barrier by plasma polymerization of isopropanol on various solid substrates, including silica and potassium chloride. This versatile technique is used to treat nanoparticles and nanopowders with sizes ranging from 37 nm to 1 micron, by depositing films whose thickness can be anywhere from 1 nm to upwards of 100 nm. Dissolution of the core allows us to study the rate of permeation through the film. In these experiments, we determine the diffusion coefficient of KCl through the barrier film by coating KCL nanocrystals and subsequently monitoring the ionic conductivity of the coated particles suspended in water. The primary interest in this process is the encapsulation and delayed release of solutes. The thickness of the shell is one of the independent variables by which we control the rate of release. It has a strong effect on the rate of release, which increases from a six-hour release (shell thickness is 20 nm) to a long-term release over 30 days (shell thickness is 95 nm). The release profile shows a characteristic behavior: a fast release (35% of the final materials) during the first five minutes after the beginning of the dissolution, and a slower release till all of the core materials come out.

We have used plasma enhanced chemical vapor deposition to deposit thin films ranging from a few nm to several 100 nm on nano-sized particles of various materials. We subsequently etch the core material to produce hollow nanoshells whose permeability is controlled by the thickness of the shell. We characterize the permeability of these coatings to small solutes and demonstrate that these barriers can provide sustained release of the core material over several days.

等离子体聚合空心颗粒的封装和渗透特征

In this protocol, core-shell nanostructures are synthesized by plasma enhanced chemical vapor deposition. We produce an amorphous barrier by plasma ...

科研

工程学

Molecular Beam Mass Spectrometry With Tunable Vacuum Ultraviolet (VUV) Synchrotron Radiation

Tunable soft ionization coupled to mass spectroscopy is a powerful method to investigate isolated molecules, complexes and clusters and their spectroscopy and dynamics1-4. Fundamental studies of photoionization processes of biomolecules provide information about the electronic structure of these systems. Furthermore determinations of ionization energies and other properties of biomolecules in the gas phase are not trivial, and these experiments provide a platform to generate these data. We have developed a thermal vaporization technique coupled with supersonic molecular beams that provides a gentle way to transport these species into the gas phase. Judicious combination of source gas and temperature allows for formation of dimers and higher clusters of the DNA bases. The focus of this particular work is on the effects of non-covalent interactions, i.e., hydrogen bonding, stacking, and electrostatic interactions, on the ionization energies and proton transfer of individual biomolecules, their complexes and upon micro-hydration by water1, 5-9.
We have performed experimental and theoretical characterization of the photoionization dynamics of gas-phase uracil and 1,3-dimethyluracil dimers using molecular beams coupled with synchrotron radiation at the Chemical Dynamics Beamline10 located at the Advanced Light Source and the experimental details are visualized here. This allowed us to observe the proton transfer in 1,3-dimethyluracil dimers, a system with pi stacking geometry and with no hydrogen bonds1. Molecular beams provide a very convenient and efficient way to isolate the sample of interest from environmental perturbations which in return allows accurate comparison with electronic structure calculations11, 12. By tuning the photon energy from the synchrotron, a photoionization efficiency (PIE) curve can be plotted which informs us about the cationic electronic states. These values can then be compared to theoretical models and calculations and in turn, explain in detail the electronic structure and dynamics of the investigated species 1, 3.

Molecular Beam Mass Spectrometry With Tunable Vacuum Ultraviolet VUV Synchrotron Radiation

A molecular beam coupled to tunable vacuum ultraviolet photoionization mass spectrometer at a synchrotron provides a convenient tool to explore the electronic structure of isolated gas phase molecules and clusters. Proton transfer mechanisms in DNA base dimers were elucidated with this technique.

可调式真空紫外（VUV）同步辐射分子束质谱分析

Tunable soft ionization coupled to mass spectroscopy is a powerful method to investigate isolated molecules, complexes and clusters and their spectroscopy ...

Activating Molecules, Ions, and Solid Particles with Acoustic Cavitation

The chemical and physical effects of ultrasound arise not from a direct interaction of molecules with sound waves, but rather from the acoustic cavitation: the nucleation, growth, and implosive collapse of microbubbles in liquids submitted to power ultrasound. The violent implosion of bubbles leads to the formation of chemically reactive species and to the emission of light, named sonoluminescence. In this manuscript, we describe the techniques allowing study of extreme intrabubble conditions and chemical reactivity of acoustic cavitation in solutions. The analysis of sonoluminescence spectra of water sparged with noble gases provides evidence for nonequilibrium plasma formation. The photons and the "hot" particles generated by cavitation bubbles enable to excite the non-volatile species in solutions increasing their chemical reactivity. For example the mechanism of ultrabright sonoluminescence of uranyl ions in acidic solutions varies with uranium concentration: sonophotoluminescence dominates in diluted solutions, and collisional excitation contributes at higher uranium concentration. Secondary sonochemical products may arise from chemically active species that are formed inside the bubble, but then diffuse into the liquid phase and react with solution precursors to form a variety of products. For instance, the sonochemical reduction of Pt(IV) in pure water provides an innovative synthetic route for monodispersed nanoparticles of metallic platinum without any templates or capping agents. Many studies reveal the advantages of ultrasound to activate the divided solids. In general, the mechanical effects of ultrasound strongly contribute in heterogeneous systems in addition to chemical effects. In particular, the sonolysis of PuO2 powder in pure water yields stable colloids of plutonium due to both effects.

Acoustic cavitation in liquids submitted to power ultrasound creates transient extreme conditions inside the collapsing bubbles, which are the origin of unusual chemical reactivity and light emission, known as sonoluminescence. In the presence of noble gases, nonequilibrium plasma is formed. The "hot" particles and the photons generated by collapsing bubbles are able to excite species in solution.

活化分子，离子和固体颗粒与声空化

The chemical and physical effects of ultrasound arise not from a direct interaction of molecules with sound waves, but rather from the acoustic ...

化学

How to Ignite an Atmospheric Pressure Microwave Plasma Torch without Any Additional Igniters

This movie shows how an atmospheric pressure plasma torch can be ignited by microwave power with no additional igniters. After ignition of the plasma, a stable and continuous operation of the plasma is possible and the plasma torch can be used for many different applications. On one hand, the hot (3,600 K gas temperature) plasma can be used for chemical processes and on the other hand the cold afterglow (temperatures down to almost RT) can be applied for surface processes. For example chemical syntheses are interesting volume processes. Here the microwave plasma torch can be used for the decomposition of waste gases which are harmful and contribute to the global warming but are needed as etching gases in growing industry sectors like the semiconductor branch. Another application is the dissociation of CO2. Surplus electrical energy from renewable energy sources can be used to dissociate CO2 to CO and O2. The CO can be further processed to gaseous or liquid higher hydrocarbons thereby providing chemical storage of the energy, synthetic fuels or platform chemicals for the chemical industry. Applications of the afterglow of the plasma torch are the treatment of surfaces to increase the adhesion of lacquer, glue or paint, and the sterilization or decontamination of different kind of surfaces. The movie will explain how to ignite the plasma solely by microwave power without any additional igniters, e.g., electric sparks. The microwave plasma torch is based on a combination of two resonators &#8212; a coaxial one which provides the ignition of the plasma and a cylindrical one which guarantees a continuous and stable operation of the plasma after ignition. The plasma can be operated in a long microwave transparent tube for volume processes or shaped by orifices for surface treatment purposes.

This movie shows how an atmospheric plasma torch can be ignited by microwaves with no additional igniters and provides a stable and continuous plasma operation suitable for plenty of applications.

如何点燃常压微波等离子体炬没有任何额外的点火器

This movie shows how an atmospheric pressure plasma torch can be ignited by microwave power with no additional igniters. After ignition of the plasma, a ...

Basic Research in Plasma Medicine - A Throughput Approach from Liquids to Cells

In plasma medicine, ionized gases with temperatures close to that of vertebrate systems are applied to cells and tissues. Cold plasmas generate reactive species known to redox regulate biological processes in health and disease. Pre-clinical and clinical evidence points to beneficial effects of plasma treatment in the healing of chronic ulcer of the skin. Other emerging topics, such as plasma cancer treatment, are receiving increasing attention. Plasma medical research requires interdisciplinary expertise in physics, chemistry, and biomedicine. One goal of plasma research is to characterize plasma-treated cells in a variety of specific applications. This includes, for example, cell count and viability, cellular oxidation, mitochondrial activity, cytotoxicity and mode of cell death, cell cycle analysis, cell surface marker expression, and cytokine release. This study describes the essential equipment and workflows required for such research in plasma biomedicine. It describes the proper operation of an atmospheric pressure argon plasma jet, specifically monitoring its basic emission spectra and feed gas settings to modulate reactive species output. Using a high-precision xyz-table and computer software, the jet is hovered in millisecond-precision over the cavities of 96-well plates in micrometer-precision for maximal reproducibility. Downstream assays for liquid analysis of redox-active molecules are shown, and target cells are plasma-treated. Specifically, melanoma cells are analyzed in an efficient sequence of different consecutive assays but using the same cells: measurement of metabolic activity, total cell area, and surface marker expression of calreticulin, a molecule important for the immunogenic cell death of cancer cells. These assays retrieve content-rich biological information about plasma effects from a single plate. Altogether, this study describes the essential steps and protocols for plasma medical research.

A high-throughput cold physical plasma treatment protocol of liquids and cells is shown. It involves setting up different feed gas compositions for plasma ignition, measuring the plasma&#39;s emission spectra, and the subsequent analysis of liquids and cellular activity after plasma treatment.

等离子体医学基础研究--从液体到细胞的吞吐量方法

In plasma medicine, ionized gases with temperatures close to that of vertebrate systems are applied to cells and tissues. Cold plasmas generate reactive ...

环境科学

Experimental Protocol to Investigate Particle Aerosolization of a Product Under Abrasion and Under Environmental Weathering

The present article presents an experimental protocol to investigate particle aerosolization of a product under abrasion and under environmental weathering, which is a fundamental element to the approach of nanosafety-by-design of nanostructured products for their durable development. This approach is basically a preemptive one in which the focus is put on minimizing the emission of engineered nanomaterials' aerosols during the usage phase of the product's life cycle. This can be attained by altering its material properties during its design phase without compromising with any of its added benefits. In this article, an experimental protocol is presented to investigate the nanosafety-by-design of three commercial nanostructured products with respect to their mechanical solicitation and environmental weathering. The means chosen for applying the mechanical solicitation is an abrasion process and for the environmental weathering, it is an accelerated UV exposure in the presence of humidity and heat. The eventual emission of engineered nanomaterials is studied in terms of their number concentration, size distribution, morphology and chemical composition. The purpose of the protocol is to study the emission for test samples and experimental conditions which are corresponding to real life situations. It was found that the application of the mechanical stresses alone emits the engineered nanomaterials' aerosols in which the engineered nanomaterial is always embedded inside the product matrix, thus, a representative product element. In such a case, the emitted aerosols comprise of both nanoparticles as well as microparticles. But if the mechanical stresses are coupled with the environmental weathering, the experimental protocol reveals then the eventual deterioration of the product, after a certain weathering duration, may lead to the emission of the free engineered nanomaterial aerosols too.

In this article, an experimental protocol to investigate particle aerosolization of a product under abrasion and under environmental weathering is presented. Results on the emission of engineered nanomaterials, in the form of aerosols are presented. The specific experimental set-up is described in detail.

实验协议来调查产品的粒子雾化在耐磨和环境下风化

The present article presents an experimental protocol to investigate particle aerosolization of a product under abrasion and under environmental ...

Emission Spectroscopic Boundary Layer Investigation during Ablative Material Testing in Plasmatron

Ablative Thermal Protection Systems (TPS) allowed the first humans to safely return to Earth from the moon and are still considered as the only solution for future high-speed reentry missions. But despite the advancements made since Apollo, heat flux prediction remains an imperfect science and engineers resort to safety factors to determine the TPS thickness. This goes at the expense of embarked payload, hampering, for example, sample return missions. 
Ground testing in plasma wind-tunnels is currently the only affordable possibility for both material qualification and validation of material response codes. The subsonic 1.2MW Inductively Coupled Plasmatron facility at the von Karman Institute for Fluid Dynamics is able to reproduce a wide range of reentry environments. This protocol describes a procedure for the study of the gas/surface interaction on ablative materials in high enthalpy flows and presents sample results of a non-pyrolyzing, ablating carbon fiber precursor. With this publication, the authors envisage the definition of a standard procedure, facilitating comparison with other laboratories and contributing to ongoing efforts to improve heat shield reliability and reduce design uncertainties.
The described core techniques are non-intrusive methods to track the material recession with a high-speed camera along with the chemistry in the reactive boundary layer, probed by emission spectroscopy. Although optical emission spectroscopy is limited to line-of-sight measurements and is further constrained to electronically excited atoms and molecules, its simplicity and broad applicability still make it the technique of choice for analysis of the reactive boundary layer. Recession of the ablating sample further requires that the distance of the measurement location with respect to the surface is known at all times during the experiment. Calibration of the optical system of the applied three spectrometers allowed quantitative comparison. At the fiber scale, results from a post-test microscopy analysis are presented.

Development of new ablative materials and their numerical modeling requires extensive experimental investigation. This protocol describes procedures for material response characterization in plasma flows with the core techniques being non-intrusive methods to track the material recession along with the chemistry in the reactive boundary layer by emission spectroscopy.

烧蚀材料在试验过程中等离子体发生器发射光谱边界层研究

Ablative Thermal Protection Systems (TPS) allowed the first humans to safely return to Earth from the moon and are still considered as the only solution ...

Non-equilibrium Microwave Plasma for Efficient High Temperature Chemistry

A flowing microwave plasma based methodology for converting electric energy into internal and/or translational modes of stable molecules with the purpose of efficiently driving non-equilibrium chemistry is discussed. The advantage of a flowing plasma reactor is that continuous chemical processes can be driven with the flexibility of startup times in the seconds timescale. The plasma approach is generically suitable for conversion/activation of stable molecules such as CO2, N2 and CH4. Here the reduction of CO2 to CO is used as a model system: the complementary diagnostics illustrate how a baseline thermodynamic equilibrium conversion can be exceeded by the intrinsic non-equilibrium from high vibrational excitation. Laser (Rayleigh) scattering is used to measure the reactor temperature and Fourier Transform Infrared Spectroscopy (FTIR) to characterize in situ internal (vibrational) excitation as well as the effluent composition to monitor conversion and selectivity.

This article describes a flowing microwave reactor that is used to drive efficient non-equilibrium chemistry for the application of conversion/activation of stable molecules such as CO2, N2 and CH4. The goal of the procedure described here is to measure the in situ gas temperature and gas conversion.

用于高效高温化学的非平衡微波等离子体

A flowing microwave plasma based methodology for converting electric energy into internal and/or translational modes of stable molecules with the purpose ...

An Atmospheric Pressure Plasma Setup to Investigate the Reactive Species Formation

Non-thermal atmospheric pressure (&#39;cold&#39;) plasmas have received increased attention in recent years due to their significant biomedical potential. The reactions of cold plasma with the surrounding atmosphere yield a variety of reactive species, which can define its effectiveness. While efficient development of cold plasma therapy requires kinetic models, model benchmarking needs empirical data. Experimental studies of the source of reactive species detected in aqueous solutions exposed to plasma are still scarce. Biomedical plasma is often operated with He or Ar feed gas, and a specific interest lies in investigation of the reactive species generated by plasma with various gas admixtures (O2, N2, air, H2O vapor, etc.) Such investigations are very complex due to difficulties in controlling the ambient atmosphere in contact with the plasma effluent. In this work, we addressed common issues of &#39;high&#39; voltage kHz frequency driven plasma jet experimental studies. A reactor was developed allowing the exclusion of ambient atmosphere from the plasma-liquid system. The system thus comprised the feed gas with admixtures and the components of the liquid sample. This controlled atmosphere allowed the investigation of the source of the reactive oxygen species induced in aqueous solutions by He-water vapor plasma. The use of isotopically labelled water allowed distinguishing between the species originating in the gas phase and those formed in the liquid. The plasma equipment was contained inside a Faraday cage to eliminate possible influence of any external field. The setup is versatile and can aid in further understanding the cold plasma-liquid interactions chemistry.

An experimental setup was created for the helium-operated kHz frequency plasma jet. The setup includes a cage for the plasma power supply and jet and an in-house built reactor to monitor plasma-induced reactive species without the interference of the ambient atmosphere.

大气压等离子体设置调查活性物种形成

Non-thermal atmospheric pressure (&#39;cold&#39;) plasmas have received increased attention in recent years due to their significant biomedical potential. ...

Treating Surfaces with a Cold Atmospheric Pressure Plasma using the COST-Jet

In recent years, non-thermal atmospheric pressure plasmas have been used extensively for surface treatments, in particular, due to their potential in biological applications. However, the scientific results often suffer from reproducibility problems due to unreliable plasma conditions as well as complex treatment procedures. To address this issue and provide a stable and reproducible plasma source, the COST-Jet reference source was developed.
In this work, we propose a detailed protocol to perform reliable and reproducible surface treatments using the COST reference microplasma jet (COST-Jet). Common issues and pitfalls are discussed, as well as the peculiarities of the COST-Jet compared to other devices and its advantageous remote character. A detailed description of both solid and liquid surface treatment is provided. The described methods are versatile and can be adapted for other types of atmospheric pressure plasma devices.

This protocol is presented to characterize the setup, handling, and application of the COST-Jet for the treatment of diverse surfaces such as solids and liquids.

使用成本喷气机用冷大气压力等离子体处理表面

In recent years, non-thermal atmospheric pressure plasmas have been used extensively for surface treatments, in particular, due to their potential in ...