uv photoion density measurements using a high‐pressure Langmuir probe

1978 ◽  
Vol 49 (2) ◽  
pp. 584-589
Author(s):  
J. Santiago ◽  
A. M. Robinson
Keyword(s):  
High Pressure ◽  
Langmuir Probe ◽  
Density Measurements

High-Pressure Density Measurements for the Binary System Ethanol + Heptane

2006 ◽  
Vol 51 (1) ◽  
pp. 112-118 ◽  
Author(s):  
Guillaume Watson ◽  
Claus K. Zéberg-Mikkelsen ◽  
Antoine Baylaucq ◽  
Christian Boned
Keyword(s):  
High Pressure ◽  
Binary System ◽  
Density Measurements

scholarly journals Solar flares observed by Rosetta at comet 67P/Churyumov-Gerasimenko

2019 ◽  
Vol 630 ◽  
pp. A49 ◽  
Author(s):  
N. J. T. Edberg ◽  
F. L. Johansson ◽  
A. I. Eriksson ◽  
D. J. Andrews ◽  
R. Hajra ◽  
...  
Keyword(s):  
Plasma Density ◽  
Solar Flares ◽  
Langmuir Probe ◽  
Extreme Ultraviolet ◽  
Vantage Point ◽  
Spectral Model ◽  
Time Of Arrival ◽  
Observable Effect ◽  
Density Measurements ◽  
Comet 67P

Context. The Rosetta spacecraft made continuous measurements of the coma of comet 67P/Churyumov-Gerasimenko (67P) for more than two years. The plasma in the coma appeared very dynamic, and many factors control its variability. Aims. We wish to identify the effects of solar flares on the comet plasma and also their effect on the measurements by the Langmuir Probe Instrument (LAP). Methods. To identify the effects of flares, we proceeded from an existing flare catalog of Earth-directed solar flares, from which a new list was created that only included Rosetta-directed flares. We also used measurements of flares at Mars when at similar longitudes as Rosetta. The flare irradiance spectral model (FISM v.1) and its Mars equivalent (FISM-M) produce an extreme-ultraviolet (EUV) irradiance (10–120 nm) of the flares at 1 min resolution. LAP data and density measurements obtained with the Mutual Impedence Probe (MIP) from the time of arrival of the flares at Rosetta were examined to determine the flare effects. Results. From the vantage point of Earth, 1504 flares directed toward Rosetta occurred during the mission. In only 24 of these, that is, 1.6%, was the increase in EUV irradiance large enough to cause an observable effect in LAP data. Twenty-four Mars-directed flares were also observed in Rosetta data. The effect of the flares was to increase the photoelectron current by typically 1–5 nA. We find little evidence that the solar flares increase the plasma density, at least not above the background variability. Conclusions. Solar flares have a small effect on the photoelectron current of the LAP instrument, and they are not significant in comparison to other factors that control the plasma density in the coma. The photoelectron current can only be used for flare detection during periods of calm plasma conditions.

Mechanical Behavior of the Cr3C2 Compound at High Pressure and High Temperature

2015 ◽  
Vol 1120-1121 ◽  
pp. 1187-1193 ◽  
Author(s):  
Bin Li Jiang ◽  
Zi Li Kou ◽  
De Jiang Ma ◽  
Yong Kun Wang ◽  
Chun Xia Li ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Fracture Toughness ◽  
High Pressure ◽  
Relative Density ◽  
X Ray Diffraction ◽  
Density Measurements ◽  
X Ray ◽  
Hardness Tests ◽  
Novel Method ◽  
Heat Preservation

In the present study, we present a novel method to sinter Cr3C2 powders under high pressure without any addittives. The sintering Cr3C2 samples were charaterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), relative density measurements, Vicker’s hardness tests and Fracture toughness tests. The reasults show that Cr3C2 powders could be sintered to be bulk under the conditions of 3-5 GPa, 800-1200 °C and the heat preservation for 15 min. Moreover, the sintering body of Cr3C2 compound with the relative density of 99.84% by simultaneously tuning the pressure-temperature conditions exhibited excellent mechanical properties: a Vickers hardness of 20.3 GPa and a fracture toughness of ~8.9 MPam1/2. These properties were much higher than that by using the previous methods. The temperature condition obtained good mechanical properties in the experiment was about 1/3 lower than that using any other methods owing to the high pressure.

Multi-Needle Langmuir Probe System for Electron Density Measurements and Active Spacecraft Potential Control on CubeSats

2019 ◽  
Vol 55 (6) ◽  
pp. 2951-2964 ◽  
Author(s):  
Tore Andre Bekkeng ◽  
Espen Sorlie Helgeby ◽  
Arne Pedersen ◽  
Espen Trondsen ◽  
Torfinn Lindem ◽  
...  
Keyword(s):  
Electron Density ◽  
Langmuir Probe ◽  
Density Measurements ◽  
Potential Control ◽  
Spacecraft Potential ◽  
Probe System

scholarly journals Thermoelastic properties of liquid Fe‐C revealed by sound velocity and density measurements at high pressure

2016 ◽  
Vol 121 (11) ◽  
pp. 7984-7995 ◽  
Author(s):  
Yuta Shimoyama ◽  
Hidenori Terasaki ◽  
Satoru Urakawa ◽  
Yusaku Takubo ◽  
Soma Kuwabara ◽  
...  
Keyword(s):  
High Pressure ◽  
Sound Velocity ◽  
Thermoelastic Properties ◽  
Density Measurements

High-temperature and high-pressure density measurements and other derived thermodynamic properties of 1-butyl-3-methylimidazolium tris (pentafluoroethyl) trifluorophosphate

2017 ◽  
Vol 658 ◽  
pp. 14-23 ◽  
Author(s):  
Javid Safarov ◽  
Felix Lesch ◽  
Khagani Suleymanli ◽  
Abilgani Aliyev ◽  
Astan Shahverdiyev ◽  
...  
Keyword(s):  
High Pressure ◽  
High Temperature ◽  
Thermodynamic Properties ◽  
Density Measurements

scholarly journals Polymorphism of 1,3-X-adamantanes (X = Br, OH, CH3) and the crystal plastic phase formation ability

CrystEngComm ◽  
2020 ◽  
Vol 22 (7) ◽  
pp. 1230-1238 ◽  
Author(s):  
Philippe Negrier ◽  
Bacem Ben Hassine ◽  
Maria Barrio ◽  
Michela Romanini ◽  
Denise Mondieig ◽  
...  
Keyword(s):  
Differential Scanning Calorimetry ◽  
High Pressure ◽  
Phase Formation ◽  
Powder Diffraction ◽  
Scanning Calorimetry ◽  
Density Measurements ◽  
X Ray ◽  
Plastic Phase

The polymorphism of 1,3-dimethyladamantane (13DMA), 1,3-adamantanediol (13DOHA) and 1,3-dibromoadamantane (13DBrA) has been studied by X-ray powder diffraction, density measurements and differential scanning calorimetry at normal and high-pressure.

Density and composition of the lower mantle

1989 ◽  
Vol 328 (1599) ◽  
pp. 377-389 ◽  
Keyword(s):  
High Pressure ◽  
Density Distribution ◽  
Upper Mantle ◽  
Lower Mantle ◽  
Mineral Assemblage ◽  
Geophysical Data ◽  
Density Difference ◽  
Depth Range ◽  
Density Measurements ◽  
Mantle Composition

The observed density distribution of the lower mantle is compared with density measurements of the (M g,Fe)SiO 3 perovskite and (Mg,Fe)O magnesiowtistite highpressure phases as functions of pressure, tem perature and composition. We find that for plausible bounds on the composition of the upper mantle (ratio of magnesium to iron + magnesium components x M g ^ 0.88) and the temperature in the lower mantle ( T ^ 2000 K), the high-pressure mineral assemblage of upper-mantle composition is at least 2 .6 ( ± 1 ) % less dense than the lower m antle over the depth range 1000-2000 km. Thus, we find that a model of uniform m antle composition is incompatible with the existing mineralogical and geophysical data. Instead, we expect that the mantle is stratified, with the upper and lower m antle convecting separately, and we estimate that the compositional density difference between these regions is about 5 ( + 2) %. The stratification may not be perfect (‘leaky layering’), but significant intermixing and homogenization of the upper and lower m antle over geological timescales are precluded.

Sign in / Sign up

Export Citation Format

Share Document