The authors would like to thank Matt Reinke and the Alcator C-Mod team for designing, building, and testing HIREXSR. This work was supported by DOE Contract Nos. DE-FC02-99ER54512 and DE-AC02-76CH03073.

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The authors have nothing to disclose.

이 기술에 의해 생성 된 데이터는 실험 연구에 광범위하게 사용될 수있다. 이온 온도 도넛 속도 프로파일은 진성 자체 생성 플라즈마 회전 및 비 로컬 섭동 효과를 포함하여 전송 연구의 넓은 범위에서 사용할 수있다. 하워드 등. 2011 10에서 수행되었을 때 레이저 분출을 통해 주입 된 불순물의 스펙트럼을 측정하면, 플라즈마의 불순물의 전송에 대한 중요한 정보를 제공 할 수 있습?...

X 선 스펙트럼은 고온 플라즈마에 대한 풍부한 정보를 제공한다; 예를 들면 전자 온도 및 밀도 선 강도 비로부터 추론 될 수있다. 축외 플라즈마를 보는 요한 분광기를 사용함으로써, 이러한 우수한 공간 및 시간 해상도를 가진 1,2- 플라즈마 내부의 밀도, 온도 및 속도와 같은 플라즈마 파라미터 정보를 구성 할 수있다. 이 원고는 공간 해상도와 고해상도 X 선 크리스탈 영상 분광계 (HIREXSR), 공간적으로 토카막 중간 원자 번호 원소의 수소와 헬륨 등의 이온을 확인하는 데 사용되는 X 선 분광계 이미징 높은 파장 해상도의 동작을 제공합니다 혈장. HIREXSR는 Alcator C-모, 각각 0.67 m와 0.22 m의 크고 작은 반경 토카막 핵융합 장치에 배포됩니다. 그것은 일반적으로 중수소 플라즈마 20 10 × 0.2-8.0 사이 m 평균 밀도 ~ 2 초 지속으로 동작 -3 </su1-9 keV의 3 사이의 P&gt; 중앙 전자 온도. 이러한 조건 하에서, 높은 Z 불순물 원소 중간 고도로 이온화 상태가되어 대책 HIREXSR X 선 영역에서 방출. 잘 진단 실험실 플라즈마로부터 얻어지는 X 선 스펙트럼의 원자 번호 모델링 벤치마킹 다른 독립적 진단 (4)을 이용할 수없는 경우에, 플라즈마 파라미터를 결정하기 위해 이러한 스펙트럼의 사용을 정당화하는 것이 중요하다. 모든 분석기는 원하는 사용하기 위해 만들어졌습니다. 따라서, 시스템 및 관련 개념에 대한 일반적인 설명이 충분히 강력한 도구 (5)를 이해하는 것이 필요하다. 광자 결정의 인접 층에서 반사 및 파장의 배수 인 거리를 이동할 때, 브래그 반사가 발생한다. (1)는 이러한 현상을 보여주고있다. 이 조건은 n은 다시의 순서입니다 방정식 nλ = 2 일의 죄 θ의 (B)에 의해 표현된다변곡점은, λ는 광자의 파장이고, d는 액정과 θ (B)의 인접한 층 사이의 간격은 브래그 (Bragg) 각도이다. λ와 θ B 사이의 일대일 대응에 대한 하나를 나타냅니다 같은 파장 검출기 비행기 여행의 특정 시점에서 모든 광자가. 그러나 실제로, 브래그 각도 편차 매니페스트 흡수 정밀도 한계. 이것은 로킹 커브 (6)에 의해 나타내어 현저한 보강 간섭을 생성 각도의 작은 범위를 초래한다. (2)은 방해석 결정하기위한 예시도 곡선이다. HIREXSR는 구형 구부러진 결정 (7)와 요한 분석기입니다. 디바이스의이 종류를 설명하기 전에, 단순한 원형 분석 장치의 설명이 적합하다. 이 셋업은 해당 브래그가 각도에서 들어오는 광자를 반영하는 구부러진 크리스탈로 구성단일 X 선 광자 계산 픽셀 감지기 배열을 구. 도 3에 표시된 바와 같이 결정하고, 검출기는, 롤 런드 원의 접선에 누워. 롤 런드 원의 직경이 결정의 곡률 반경과 동일하다. 결정상의 임의의 지점의 둘레에 소정의 지점에서 모든 광선 결정 자체에 대해 동일한 입사각을 갖는다. .도 4에 도시 HIREXSR, 자오면에서 구형 만곡 결정 허용 공간 해상도의 경우에, 자오선 초점 F의 m은 다음과 같이 정의된다 : R (C)가 곡률 반경은 F m = R C의 죄 θ B를 결정. - f를 m / COS 2 θ의 B F의의 = 시상 초점 f를들로 정의된다. 분광계 Δ x의 공간 해상도가 주어집니다으로: <img alt="방정식" src="/files/ftp_upload/54408/54408eq_DELTA_x.jpg" /> L 개의 CP가 결정 플라즈마 간의 거리이고, D는 결정의 높이이다. 결정 층의 2 차원 공간이 분리되기 때문에 재료를 선택할 때,이 고려되어야한다. 검출기 표면이 평탄하기 때문에, 그들은 단지 검출 된 광선은 롤 런드 원의 해당 지점에 정확하게 착륙하지 않기 때문에, 결과적으로 오차를 초래 한 점에서 롤 런드 원에 접하는 수있다. 물리적으로,이 어긋남이 상기 검출기에 대한 특정 에너지의 광자 &quot;번짐&quot;로 나타난다. 이 요한 오류는 다음과 같이 정의된다 <img alt="방정식" src="/files/ftp_upload/54408/54408eq_delta_xj.jpg" /> L은 결정의 폭이다. 검출기 픽셀 폭 ΔX P가 요한 오차보다 큰 경우, 상기 스펙트럼 해상도는 독립적이다. 그들은 경우유사한 크기의 재 후 총 에러로 근사화 될 수있다 <img alt="방정식" src="/files/ftp_upload/54408/54408eq_delta_x_2.jpg" /> . 결정 분광기의 분해능이 주어진다 : <img alt="방정식" src="/files/ftp_upload/54408/54408eq_lambda0.jpg" /> 여기서 <img alt="방정식" src="/files/ftp_upload/54408/54408eq_delta_theta.jpg" /> . 도 5에 도시 된 바와 같이, 대신 HIREXSR 그러나 롤 런드 원에 지점 검출기 접선 배치의 검출기는, 스펙트럼 범위의 정확도를 희생 약간 경사져.이 에러 분석은 실험적으로 확인되었으므로 기대 (8)에 따른다. 요한 분석기를 설계 할 때 고려해야 할 두 가지 중요한 매개 변수가 있습니다. 우선, 촬상 범위는 분광계 관찰 될지를 결정한다. 플라즈마 연구를 들면, 폴로 이달 및 toroi 의한 광고 변화를 구별하기 위해 그것의 전체 단면을 확인하는 것이 매우 바람직하다DAL 회전. HIREXSR는 전체 플라즈마를 볼 수 있도록 장착되고, 도넛 정확한 측정을 허용하도록 (도 6에 도시) ~8 °로 떨어져 축이 약간 경사. 둘째, 시간 해상도는 분광계가 기록 할 수있는 이벤트 사이의 최소 시간을 조절한다. Alcator C-모 들어, 바람직한 값은 에너지와 입자 제한 시간보다 짧은 20 이하 밀리가 있습니다. HIREXSR 용도가 20 밀리 초 이상으로 6 시간 해상도를 지원할 수있는 X 선 계산 픽셀 감지기 (9). 표 1은 모듈 사양 모두를 요약 한 것이다. 섭동 플라즈마 연구의 경우, Alcator C-모에 레이저 블로우 - 오프 시스템은 정확한 타이밍 (10) 여러 절제를 제공하는 데 사용됩니다. 레이저는 노스 다코타입니다 : 최대 10 Hz에서 운영 YAG (네오디뮴 도핑 된 이트륨 알루미늄 석류석). 초점도 7을 조향에 도시 된 바와 같이 레이저가 원격 제어 광 트레인에 입사이고상기 슬라이드상의 원하는 위치로 빔. 레이저 스폿 크기는 주입 플라즈마를 방해하지 않도록 제어 할 필요가있다. 긴 초점 길이 (1,146mm) 집광 렌즈 절제된 스폿 사이즈 ~ 0.5 내지 7 mm로 변화 할 수 있도록 원격 제어 선형 단계를 통해 광축을 따라 변환된다. 빠른 빔 스티어링은 2D 압전 거울을 통해 달성된다. 이 압전 시스템가 RS232 구동 미러에 장착되어있는 마운트합니다. 가진 Nd 외에 : YAG 레이저, 633 nm의 다이오드 레이저 주 (적외선) 빔의 위치를​​ 표시하기 위해 사용된다. 빔은 제 1 미러를 통해 동일 선상되도록 만들어진다.

<table><tbody><tr><td>PILATUS 100k Detector System</td><td>DECTRIS</td><td>100k</td><td>Superseded by newer PILATUS3 detectors</td></tr><tr><td>Bragg Crystals</td><td>Kurchaov Institute</td><td>Custom Part</td><td></td></tr><tr><td>CaF&lt;sub&gt;2&lt;/sub&gt; Slides</td><td>LeBow</td><td>Custom Part</td><td></td></tr><tr><td>High Purity Argon</td><td>Airgas</td><td>AR HP300</td><td>Any high purity argon should work</td></tr><tr><td>Be window</td><td>Brush Wellman Electrofusion Products / Motion Hightech</td><td>Custom part</td><td></td></tr></tbody></table>

applying x-ray imaging crystal spectroscopy for use as a high temperature plasma diagnostic

X 선 스펙트럼은 고온 플라즈마에 대한 풍부한 정보를 제공한다; 예를 들면 전자 온도 및 밀도 선 강도 비로부터 추론 될 수있다. 플라즈마를 보는 요한 분광기를 사용함으로써, 이러한 양호한 시간 및 공간 해상도의 밀도, 온도 및 속도와 같은 플라즈마 파라미터 정보를 구성 할 수있다. 그러나, 잘 진단 실험실 플라즈마로부터 얻어지는 X 선 스펙트럼의 원자 번호 모델링 벤치마킹 다른 독립적 인 진단을 이용할 수없는 경우에, 플라즈마 파라미터를 결정하기 위해 이러한 스펙트럼의 사용을 정당화하는 것이 중요하다. 이 원고는 공간 해상도와 고해상도 X 선 크리스탈 영상 분광계 (HIREXSR), 공간적으로 토카막 중간 원자 번호 원소의 수소와 헬륨 등의 이온을 확인하는 데 사용되는 X 선 분광계 이미징 높은 파장 해상도의 동작을 제공합니다 혈장. 또한,이 원고는 이온을 도입 할 수있는 레이저 분출 시스템을 포함정확한 타이밍으로 플라즈마에 플라즈마 수송의 섭동 연구를 허용합니다.

헬륨 같은 아르곤의 스펙트럼을 한 번 빈의 픽셀 검출기에서 대표적인 데이터 샘플이 그림 17에 표시됩니다. 구형 결정에 의해 타원형 모양으로 구부러진 스펙트럼 라인을 명확하게 볼 수 있습니다. 상부 탐지기는 고장 검출기 패널을 갖고, 검출기 모두 흩어져 죽은 픽셀이있다. 깨진 검출기 패널의 데이터는 무시해야합니다. 측정 된 스펙트럼은 단일 코드 위...

Watch this Scientific Journal Video about Applying X-ray Imaging Crystal Spectroscopy for Use as a High Temperature Plasma Diagnostic at JoVE.com

Applying X-ray Imaging Crystal Spectroscopy for Use as a High Temperature Plasma Diagnostic

X 선 스펙트럼은 고온 플라즈마에 풍부한 정보를 제공합니다. 이 원고는 공간적으로 토카막 플라즈마 중간 원자 번호 원소의 수소와 헬륨 등의 이온을 확인하는 데 사용되는 X 선 분광계 이미징 높은 파장 해상도의 동작을 제공합니다.

하이 온도 플라즈마 진단으로 사용하기 위해 X 선 영상 크리스탈 분광학 적용

X-ray spectra provide a wealth of information on high temperature plasmas; for example electron temperature and density can be inferred from line ...

applying-x-ray-imaging-crystal-spectroscopy-for-use-as-high

Universidad de Cartagena UDEC

Research

JoVE Journal

Engineering

11.3K 조회수.  Massachusetts Institute of Technology.  X 선 스펙트럼은 고온 플라즈마에 풍부한 정보를 제공합니다. 이 원고는 공간적으로 토카막 플라즈마 중간 원자 번호 원소의 수소와 헬륨 등의 이온을 확인하는 데 사용되는 X 선 분광계 이미징 높은 파장 해상도의 동작을 제공합니다. 

비디오: Applying X-ray Imaging Crystal Spectroscopy for Use as a High Temperature Plasma Diagnostic

Investigation of Early Plasma Evolution Induced by Ultrashort Laser Pulses

Early plasma is generated owing to high intensity laser irradiation of target and the subsequent target material ionization. Its dynamics plays a significant role in laser-material interaction, especially in the air environment1-11.
Early plasma evolution has been captured through pump-probe shadowgraphy1-3 and interferometry1,4-7. However, the studied time frames and applied laser parameter ranges are limited. For example, direct examinations of plasma front locations and electron number densities within a delay time of 100 picosecond (ps) with respect to the laser pulse peak are still very few, especially for the ultrashort pulse of a duration around 100 femtosecond (fs) and a low power density around 1014 W/cm2. Early plasma generated under these conditions has only been captured recently with high temporal and spatial resolutions12. The detailed setup strategy and procedures of this high precision measurement will be illustrated in this paper. The rationale of the measurement is optical pump-probe shadowgraphy: one ultrashort laser pulse is split to a pump pulse and a probe pulse, while the delay time between them can be adjusted by changing their beam path lengths. The pump pulse ablates the target and generates the early plasma, and the probe pulse propagates through the plasma region and detects the non-uniformity of electron number density. In addition, animations are generated using the calculated results from the simulation model of Ref. 12 to illustrate the plasma formation and evolution with a very high resolution (0.04 ~ 1 ps).
Both the experimental method and the simulation method can be applied to a broad range of time frames and laser parameters. These methods can be used to examine the early plasma generated not only from metals, but also from semiconductors and insulators.

An experimental method to examine the early plasma evolution induced by ultrashort laser pulses is described. Using this method, high quality images of early plasma are obtained with high temporal and spatial resolutions. A novel integrated atomistic model is used to simulate and explain the mechanisms of early plasma.

초기 플라즈마 진화의 조사는 극단으로 짧은 레이저 펄스에 의해 유도된

Early plasma is generated owing to high intensity laser irradiation of target and the subsequent target material ionization. Its dynamics plays a ...

연구

공학

Angle-resolved Photoemission Spectroscopy At Ultra-low Temperatures

The physical properties of a material are defined by its electronic structure. Electrons in solids are characterized by energy (&omega;) and momentum (k) and the probability to find them in a particular state with given &omega; and k is described by the spectral function A(k, &omega;). This function can be directly measured in an experiment based on the well-known photoelectric effect, for the explanation of which Albert Einstein received the Nobel Prize back in 1921. In the photoelectric effect the light shone on a surface ejects electrons from the material. According to Einstein, energy conservation allows one to determine the energy of an electron inside the sample, provided the energy of the light photon and kinetic energy of the outgoing photoelectron are known. Momentum conservation makes it also possible to estimate k relating it to the momentum of the photoelectron by measuring the angle at which the photoelectron left the surface. The modern version of this technique is called Angle-Resolved Photoemission Spectroscopy (ARPES) and exploits both conservation laws in order to determine the electronic structure, i.e. energy and momentum of electrons inside the solid. In order to resolve the details crucial for understanding the topical problems of condensed matter physics, three quantities need to be minimized: uncertainty* in photon energy, uncertainty in kinetic energy of photoelectrons and temperature of the sample.
In our approach we combine three recent achievements in the field of synchrotron radiation, surface science and cryogenics. We use synchrotron radiation with tunable photon energy contributing an uncertainty of the order of 1 meV, an electron energy analyzer which detects the kinetic energies with a precision of the order of 1 meV and a He3 cryostat which allows us to keep the temperature of the sample below 1 K. We discuss the exemplary results obtained on single crystals of Sr2RuO4 and some other materials. The electronic structure of this material can be determined with an unprecedented clarity.

The overall goal of this method is to determine the low-energy electronic structure of solids at ultra-low temperatures using Angle-Resolved Photoemission Spectroscopy with synchrotron radiation.

울트라 낮은 온도에서 각도 - 해결 Photoemission 분광법

The physical properties of a material are defined by its  electronic structure. Electrons in solids are characterized by energy (&omega;)  and momentum ...

Synthesis and Microdiffraction at Extreme Pressures and Temperatures

High pressure compounds and polymorphs are investigated for a broad range of purposes such as determine structures and processes of deep planetary interiors, design materials with novel properties, understand the mechanical behavior of materials exposed to very high stresses as in explosions or impacts. Synthesis and structural analysis of materials at extreme conditions of pressure and temperature entails remarkable technical challenges. In the laser heated diamond anvil cell (LH-DAC), very high pressure is generated between the tips of two opposing diamond anvils forced against each other; focused infrared laser beams, shined through the diamonds, allow to reach very high temperatures on samples absorbing the laser radiation. When the LH-DAC is installed in a synchrotron beamline that provides extremely brilliant x-ray radiation, the structure of materials under extreme conditions can be probed in situ. LH-DAC samples, although very small, can show highly variable grain size, phase and chemical composition. In order to obtain the high resolution structural analysis and the most comprehensive characterization of a sample, we collect diffraction data in 2D grids and combine powder, single crystal and multigrain diffraction techniques. Representative results obtained in the synthesis of a new iron oxide, Fe4O5 1 will be shown.

The laser heated diamond anvil cell combined with synchrotron micro-diffraction techniques allows researchers to explore the nature and properties of new phases of matter at extreme pressure and temperature (PT) conditions. Heterogeneous samples can be characterized in situ under high pressure by 2D mapping and combined powder, single-crystal and multigrain diffraction approaches.

극단적 인 압력과 온도에서 합성 부위 회절

High pressure compounds and polymorphs are investigated for a broad range of purposes such as determine structures and processes of deep planetary ...

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.

어떻게 추가 점화기없이 대기압 마이크로 웨이브 플라즈마 토치를 점화

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 ...

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.

Plasmatron에서 절제 재료 시험 중에 방출 분광 경계 계층 조사

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 ...

High-resolution Thermal Micro-imaging Using Europium Chelate Luminescent Coatings

Micro-electronic devices often undergo significant self-heating when biased to their typical operating conditions. This paper describes a convenient optical micro-imaging technique which can be used to map and quantify such behavior. Europium thenoyltrifluoroacetonate (EuTFC) has a 612 nm luminescence line whose activation efficiency drops strongly with increasing temperature, due to T-dependent interactions between the Eu3+ ion and the organic chelating compound. This material may be readily coated on to a sample surface by thermal sublimation in vacuum. When the coating is excited with ultraviolet light (337 nm) an optical micro-image of the 612 nm luminescent response can be converted directly into a map of the sample surface temperature. This technique offers spatial resolution limited only by the microscope optics (about 1 micron) and time resolution limited by the speed of the camera employed. It offers the additional advantages of only requiring comparatively simple and non-specialized equipment, and giving a quantitative probe of sample temperature.

Europium thenoyltrifluoroacetonate (EuTFC) has an optical luminescence line at 612 nm, whose activation efficiency decreases strongly with temperature. If a sample coated with a thin film of this material is micro-imaged, the 612 nm luminescent response intensity may be converted into a direct map of sample surface temperature.

유로퓸 킬레이트 발광 코팅을 사용하여 고해상도 열 마이크로 이미징

Micro-electronic devices often undergo significant self-heating when biased to their typical operating conditions. This paper describes a convenient ...

High Pressure Single Crystal Diffraction at PX^2

In this report we describe detailed procedures for carrying out single crystal X-ray diffraction experiments with a diamond anvil cell (DAC) at the GSECARS 13-BM-C beamline at the Advanced Photon Source. The DAC program at 13-BM-C is part of the Partnership for Extreme Xtallography (PX^2) project. BX-90 type DACs with conical-type diamond anvils and backing plates are recommended for these experiments. The sample chamber should be loaded with noble gas to maintain a hydrostatic pressure environment. The sample is aligned to the rotation center of the diffraction goniometer. The MARCCD area detector is calibrated with a powder diffraction pattern from LaB6. The sample diffraction peaks are analyzed with the ATREX software program, and are then indexed with the RSV software program. RSV is used to refine the UB matrix of the single crystal, and with this information and the peak prediction function, more diffraction peaks can be located. Representative single crystal diffraction data from an omphacite (Ca0.51Na0.48)(Mg0.44Al0.44Fe2+0.14Fe3+0.02)Si2O6 sample were collected. Analysis of the data gave a monoclinic lattice with P2/n space group at 0.35 GPa, and the lattice parameters were found to be: a = 9.496 &#177;0.006 &#197;, b = 8.761 &#177;0.004 &#197;, c = 5.248 &#177;0.001 &#197;, &#946; = 105.06 &#177;0.03&#186;, &#945; = &#947; = 90&#186;.

In this report, we describe detailed procedures for carrying out single crystal X-ray diffraction experiments with a diamond anvil cell at the GSECARS 13-BM-C beamline at the Advanced Photon Source. ATREX and RSV programs are used to analyze the data.

고압 PX에서 단결정 회절 ^ 2

In this report we describe detailed procedures for carrying out single crystal X-ray diffraction experiments with a diamond anvil cell (DAC) at the ...

화학

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.

효율적인 고온 화학을위한 비평 형 마이크로 웨이브 플라즈마

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.

대기압 플라즈마 설치 프로그램은 반응성 종 형성을 조사하기

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

Spark Plasma Sintering Apparatus Used for the Formation of Strontium Titanate Bicrystals

A spark plasma sintering apparatus was used as a novel method for diffusion bonding of two single crystals of strontium titanate to form bicrystals with one twist grain boundary. This apparatus utilizes high uniaxial pressure and a pulsed direct current for rapid consolidation of material. Diffusion bonding of strontium titanate bicrystals without fracture, in a spark plasma sintering apparatus, is possible at high pressures due to the unusual temperature dependent plasticity behavior of strontium titanate. We demonstrate a method for the successful formation of bicrystals at accelerated time scales and lower temperatures in a spark plasma sintering apparatus compared to bicrystals formed by conventional diffusion bonding parameters. Bond quality was verified by scanning electron microscopy. A clean and atomically abrupt interface containing no secondary phases was observed using transmission electron microscopy techniques. Local changes in bonding across the boundary was characterized by simultaneous scanning transmission electron microscopy and spatially resolved electron energy-loss spectroscopy.

A viable technique for the formation of strontium titanate bicrystals at high pressure and fast heating rate via the spark plasma sintering apparatus is developed.

스트론튬 티탄 Bicrystals의 형성에 사용되는 플라즈마 소결 장치 불꽃

A spark plasma sintering apparatus was used as a novel method for diffusion bonding of two single crystals of strontium titanate to form bicrystals with ...