Concept of Solid Electrolyte Sensors for Atomic Oxygen Detection in High-Enthalpy Flows

2019 ◽  
Author(s):  
Igor Hörner ◽  
Rainer Öfele ◽  
Martin Eberhart ◽  
Stefan Loehle ◽  
Stefanos Fasoulas
Keyword(s):  
Solid Electrolyte ◽  
Atomic Oxygen ◽  
High Enthalpy ◽  
Oxygen Detection

scholarly journals Measurement of atomic oxygen in the middle atmosphere using solid electrolyte sensors and catalytic probes

2015 ◽  
Vol 8 (3) ◽  
pp. 3245-3282 ◽  
Author(s):  
M. Eberhart ◽  
S. Löhle ◽  
A. Steinbeck ◽  
T. Binder ◽  
S. Fasoulas
Keyword(s):  
Solid Electrolyte ◽  
Atomic Oxygen ◽  
Microwave Plasma ◽  
Middle Atmosphere ◽  
Detailed Knowledge ◽  
Density Profiles ◽  
Measurement Results ◽  
Reference Measurements ◽  
Vertical Scales ◽  
Catalytic Effects

Abstract. The atmospheric energy budget is largely dominated by reactions involving atomic oxygen (O). Modeling of these processes requires detailed knowledge about the distribution of this oxygen species. Understanding the mutual contributions of atomic oxygen and wave motions to the atmospheric heating is the main goal of the rocket campaign WADIS. It includes, amongst others, two of our instruments for the measurement of atomic oxygen that have both been developed with the aim of resolving density variations on small vertical scales along the trajectory. In this paper the instrument based on catalytic effects (PHLUX) is introduced briefly. The experiment employing solid electrolyte sensors (FIPEX) is presented in detail. These sensors were laboratory calibrated using a microwave plasma as a source for atomic oxygen in combination with mass spectrometer reference measurements. The spectrometer was in turn calibrated for O with a method based on methane. In order to get insight into the horizontal variability the rocket payload had instrument decks at both ends. Each housed several sensor heads measuring during both the up- and downleg of the trajectory. The WADIS campaign comprises two rocket flights during different geophysical conditions. Results from WADIS-1 are presented which was successfully launched in June 2013 from Andøya Rocket Range, Norway. FIPEX data was sampled with 100 Hz and yield atomic oxygen density profiles with a vertical resolution better than 10 m. Numerical simulations of the flow field around the rocket were done at several points of the trajectory to assess the influence of aerodynamic effects on the measurement results. Density profiles peak at 3 × 1010 cm−3 at altitudes of 93.6 and 96 km for up- and downleg respectively.

scholarly journals Atomic oxygen number densities in the MLT region measured by solid electrolyte sensors on WADIS-2

2018 ◽  
Author(s):  
Martin Eberhart ◽  
Stefan Löhle ◽  
Boris Strelnikov ◽  
Jonas Hedin ◽  
Mikhail Khaplanov ◽  
...  
Keyword(s):  
Solid Electrolyte ◽  
Atomic Oxygen ◽  
Molecular Beam ◽  
Sensor Data ◽  
Atmospheric Models ◽  
Density Profiles ◽  
Amperometric Sensors ◽  
High Vertical Resolution ◽  
Mlt Region

Abstract. Absolute profiles of atomic oxygen number densities with high vertical resolution have been determined in the MLT region from in-situ measurements by several rocket-borne solid electrolyte sensors. The amperometric sensors were operated in both controlled and uncontrolled modes and with various orientations on the fore and aft deck of the payload. Calibration was based on mass spectrometry in a molecular beam containing atomic oxygen produced in a microwave discharge. The sensor signal is proportional to the number flux onto the electrodes and the mass flow rate in the molecular beam was measured additionally to derive this quantity from the spectrometer reading. Numerical simulations provided aerodynamic correction factors to derive the atmospheric number density of atomic oxygen from the sensor data. The flight results indicate a preferable orientation of the electrode surface perpendicular to the rocket axis. While unstable during the upleg, the density profiles measured by these sensors show an excellent agreement with the atmospheric models and photometer results during the downleg of the trajectory. The high spatial resolution of the measurements allows the identification of small-scaled variations in the atomic oxygen concentration.

Atomic oxygen detection using two-photon degenerate four wave mixing

1997 ◽  
Vol 39 (1) ◽  
pp. 49-58 ◽  
Author(s):  
Y. J. Picard ◽  
F. Grisch ◽  
B. Attal-Tretout ◽  
S. Le Boiteux
Keyword(s):  
Atomic Oxygen ◽  
Four Wave Mixing ◽  
Wave Mixing ◽  
Two Photon ◽  
Oxygen Detection ◽  
Degenerate Four Wave Mixing

scholarly journals Measurement of atomic oxygen in the middle atmosphere using solid electrolyte sensors and catalytic probes

2015 ◽  
Vol 8 (9) ◽  
pp. 3701-3714 ◽  
Author(s):  
M. Eberhart ◽  
S. Löhle ◽  
A. Steinbeck ◽  
T. Binder ◽  
S. Fasoulas
Keyword(s):  
Solid Electrolyte ◽  
Atomic Oxygen ◽  
Microwave Plasma ◽  
Middle Atmosphere ◽  
Spatial Scales ◽  
Detailed Knowledge ◽  
Density Profiles ◽  
Measurement Results ◽  
Reference Measurements ◽  
Vertical Scales

Abstract. The middle- and upper-atmospheric energy budget is largely dominated by reactions involving atomic oxygen (O). Modeling of these processes requires detailed knowledge about the distribution of this oxygen species. Understanding the mutual contributions of atomic oxygen and wave motions to the atmospheric heating is the main goal of the rocket project WADIS (WAve propagation and DISsipation in the middle atmosphere). It includes, amongst others, our instruments for the measurement of atomic oxygen that have both been developed with the aim of resolving density variations on small vertical scales along the trajectory. In this paper the instrument based on catalytic effects (PHLUX: Pyrometric Heat Flux Experiment) is introduced briefly. The experiment employing solid electrolyte sensors (FIPEX: Flux φ(Phi) Probe Experiment) is presented in detail. These sensors were laboratory calibrated using a microwave plasma as a source of atomic oxygen in combination with mass spectrometer reference measurements. The spectrometer was in turn calibrated for O with a method based on methane. In order to get insight into the horizontal variability, the rocket payload had instrument decks at both ends. Each housed several sensor heads measuring during both the up- and downleg of the trajectory. The WADIS project comprises two rocket flights during different geophysical conditions. Results from WADIS-1 are presented, which was successfully launched in June 2013 from the Andøya Space Center, Norway. FIPEX data were sampled at 100 Hz and yield atomic oxygen density profiles with a vertical resolution better than 9 m. This allows density variations to be studied on very small spatial scales. Numerical simulations of the flow field around the rocket were done at several points of the trajectory to assess the influence of aerodynamic effects on the measurement results. Density profiles peak at 3 × 1010 cm−3 at altitudes of 93.6 and 96 km for the up- and downleg, respectively.

scholarly journals Atomic oxygen number densities in the mesosphere–lower thermosphere region measured by solid electrolyte sensors on WADIS-2

2019 ◽  
Vol 12 (4) ◽  
pp. 2445-2461 ◽  
Author(s):  
Martin Eberhart ◽  
Stefan Löhle ◽  
Boris Strelnikov ◽  
Jonas Hedin ◽  
Mikhail Khaplanov ◽  
...  
Keyword(s):  
Solid Electrolyte ◽  
Atomic Oxygen ◽  
Molecular Beam ◽  
Lower Thermosphere ◽  
Sensor Data ◽  
Small Scale ◽  
Density Profiles ◽  
Amperometric Sensors ◽  
High Vertical Resolution

Abstract. Absolute profiles of atomic oxygen number densities with high vertical resolution have been determined in the mesosphere–lower thermosphere (MLT) region from in situ measurements by several rocket-borne solid electrolyte sensors. The amperometric sensors were operated in both controlled and uncontrolled modes and with various orientations on the foredeck and aft deck of the payload. Calibration was based on mass spectrometry in a molecular beam containing atomic oxygen produced in a microwave discharge. The sensor signal is proportional to the number flux onto the electrodes, and the mass flow rate in the molecular beam was additionally measured to derive this quantity from the spectrometer reading. Numerical simulations provided aerodynamic correction factors to derive the atmospheric number density of atomic oxygen from the sensor data. The flight results indicate a preferable orientation of the electrode surface perpendicular to the rocket axis. While unstable during the upleg, the density profiles measured by these sensors show an excellent agreement with the atmospheric models and photometer results during the downleg of the trajectory. The high spatial resolution of the measurements allows for the identification of small-scale variations in the atomic oxygen concentration.

Comparison of LIF and solid electrolyte sensor measurements of atomic oxygen in a plasma jet

2000 ◽  
Author(s):  
Markus Feigl ◽  
Joseph Dennis ◽  
Stefanos Fasoulas ◽  
Monika Auweter-Kurtz
Keyword(s):  
Solid Electrolyte ◽  
Atomic Oxygen ◽  
Plasma Jet
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