Electron beam fluorescence methods in hypersonic aerothermodynamics

Gochberg, Lawrence A.

doi:10.1016/s0376-0421(97)00002-x

Cited by 32 publications

(10 citation statements)

References 163 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…A method of measuring T v , T r , and number density of molecules using the Electron Beam Fluorescence (EBF) technique has been widely used in the field of rarefied gas dynamics for over 50 years (Gochberg, 1997). The EBF technique uses a high-energy electron beam to excite (and often ionize) a gas molecule from a ground state to an excited electronic state by an inelastic collision with an electron.…”

Section: Introductionmentioning

confidence: 99%

N<sub>2</sub> Temperature of Vibration instrument for sounding rocket observation in the lower thermosphere

Kurihara¹,

Iwagami²,

Oyama³

2013

An Introduction to Space Instrumentation

View full text Add to dashboard Cite

The N 2 Temperature of Vibration (NTV) instrument was developed to study energetics and structure of the lower thermosphere, applying the Electron Beam Fluorescence (EBF) technique to measurements of vibrational temperature, rotational temperature and number density of atmospheric N 2 . The sounding rocket experiments using this instrument have been conducted four times, including one failure of the electron gun. Aerodynamic effects on the measurement caused by the supersonic motion of the rocket were analyzed quantitatively using three-dimensional simulation of Direct Simulation Monte Carlo (DSMC) method, and the absolute density profile was obtained through the correction of the spin modulation.

show abstract

Section: Introductionmentioning

confidence: 99%

N<sub>2</sub> Temperature of Vibration instrument for sounding rocket observation in the lower thermosphere

Kurihara¹,

Iwagami²,

Oyama³

2013

An Introduction to Space Instrumentation

View full text Add to dashboard Cite

show abstract

“…When these excited molecules return to their ground state, they emit photons at a quantum-specified wavelength. With careful selection of emission lines (Gochberg, 1997), the intensity of the net fluorescence emission is proportional to the density of the gas in the illuminated region. E-beam fluorescence provides a single diagnostic that will work with a wide range of gases and their mixtures.…”

Section: Electron Gun and Pressure Isolation Assemblymentioning

confidence: 99%

“…This line has been identified as particularly well-suited to the purposes of fluorescence probing (negligible collisional quenching, minimal secondary excitation halos, etc. (Gochberg, 1997)). Fairly precise measurements of 461.0-nm argon fluorescence have been obtained with this diagnostic setup.…”

Section: Electron Beam Fluorescence Measurementsmentioning

confidence: 99%

Microscale rarefied gas dynamics and surface interactions for EUVL and MEMS applications.

Gallis¹,

Rader²,

Castañeda³

et al. 2004

View full text Add to dashboard Cite

A combined experimental/modeling study was conducted to better understand the critical role of gas-surface interactions in rarefied gas flows. An experimental chamber and supporting diagnostics were designed and assembled to allow simultaneous measurements of gas heat flux and inter-plate gas density profiles in an axisymmetric, parallel-plate geometry. Measurements of gas density profiles and heat flux are made under identical conditions, eliminating an important limitation of earlier studies. The use of in situ, electron-beam fluorescence is demonstrated as a means to measure gas density profiles although additional work is required to improve the accuracy of this technique. Heat flux is inferred from temperature-drop measurements using precision thermistors. The system can be operated with a variety of gases (monatomic, diatomic, polyatomic, mixtures) and carefully controlled, well-characterized surfaces of different types (metals, ceramics) and conditions (smooth, rough). The measurements reported here are for 304 stainless steel plates with a standard machined surface coupled with argon, helium, and nitrogen. The resulting heat-flux and gas-density-profile data are analyzed using analytic and computational models to show that a simple Maxwell gas-surface interaction model is adequate to represent all of the observations. Based on this analysis, thermal accommodation coefficients for 304 stainless steel coupled with argon, nitrogen, and helium are determined to be 0.88, 0.80, and 0.38, respectively, with an estimated uncertainty of ±0.02. 4 AcknowledgmentThis project, LDRD 04-1413, "Microscale Rarefied Gas Dynamics and Surface Interactions for EUVL and MEMS Applications," was funded by the Laboratory Directed Research and Development (LDRD) program at Sandia National Laboratories. The authors thank Jeremy Barney for his support in automating our data acquisition procedures. 5 Table of Contents List of Tables

show abstract

“…The electron beam can be applied in materials processing, microwave generation, plasma processing, surface treatment, welding, free-electron laser 5 , besides being a tool for velocimetry in hypersonic shock tunnel 6 , that is one of application to IEAv.…”

Section: Introductionmentioning

confidence: 99%

Characterization of an Electron Gun Based on a Pseudospark for Application in Hypersonic Shock Tunnels

Guimarães

Carinhana

Oliveira

2014

45th AIAA Plasmadynamics and Lasers Conference

View full text Add to dashboard Cite

Experimental investigation of an intense pulsed electron beam based on a pseudospark is presented. The device will be used to implement the technique of electron beam fluorescence (EBF) in hypersonic shock tunnel to measures the velocity and the temperature of the flow. A three electrodes pseudospark was constructed and the voltage breakdown characteristics as function of pressure (Pachen's curve) for five gases were taken (He, Ar, Ne, N2 and synthetic air). The collimated electron beam generated by this device was analised using two current transformers and a digital photo furnished the beam diameter. Electron pulse duration about 70 ns with diameter of 5 mm and a current density about 407 A/cm 2 was generated. The EBF spectra of the gases was taken, with the spectra was calculated Nitrogen vibrational temperature by Boltzmann method and the result was about 4200K.

show abstract

Electron beam fluorescence methods in hypersonic aerothermodynamics

Cited by 32 publications

References 163 publications

N<sub>2</sub> Temperature of Vibration instrument for sounding rocket observation in the lower thermosphere

N<sub>2</sub> Temperature of Vibration instrument for sounding rocket observation in the lower thermosphere

Microscale rarefied gas dynamics and surface interactions for EUVL and MEMS applications.

Characterization of an Electron Gun Based on a Pseudospark for Application in Hypersonic Shock Tunnels

Contact Info

Product

Resources

About