Laser-induced fluorescence measurements of ion fluctuations in electron and ion presheaths
Abstract
Electrostatic flow-driven instabilities have been predicted in the presheath region of low-temperature plasmas for both ion and electron rich sheaths. The ion-acoustic fluctuations that arise from these instabilities can influence transport through an enhanced collision rate. In this work, ion fluctuation spectra were measured using laser-induced fluorescence (LIF) in the presheath region for both sheath polarities. Furthermore, the non-invasive nature of LIF compared to that of probes is particularly valuable for these measurements because the sheath and presheath around a probe may generate their own flow-driven instabilities, which obscure the measurement. Measurements were made using a recently implemented field programmable gate array-based system able to measure ion fluctuation spectra up to 1 MHz using a two-point correlation function technique. Narrow bandwidth ion fluctuations were observed near 0:46fpi (460 kHz) for both sheath polarities, where fpi is the ion plasma frequency. The observed fluctuations were significantly stronger in the electron sheath case and were observed over a larger volume of plasma. Fluctuations were measured in the ion sheath case at locations far enough from the sheath that linear theory predicts stability, suggesting that ion-acoustic instabilities generated in the relatively small unstable region near the boundary reflect from the sheath and perturbmore »
- Authors:
-
[1];
[1];
[1];
[1]
- Univ. of Iowa, Iowa City, Iowa (United States). Dept. of Physics and Astronomy
- Publication Date:
- Research Org.:
- Univ. of Iowa, Iowa City, IA (United States)
- Sponsoring Org.:
- USDOE Office of Science (SC), Fusion Energy Sciences (FES)
- OSTI Identifier:
- 1803000
- Alternate Identifier(s):
- OSTI ID: 1618161
- Grant/Contract Number:
- SC0016473
- Resource Type:
- Accepted Manuscript
- Journal Name:
- Physics of Plasmas
- Additional Journal Information:
- Journal Volume: 27; Journal Issue: 5; Journal ID: ISSN 1070-664X
- Publisher:
- American Institute of Physics (AIP)
- Country of Publication:
- United States
- Language:
- English
- Subject:
- 70 PLASMA PHYSICS AND FUSION TECHNOLOGY; Plasma waves; Plasma material interactions; Field programmable gate array; Plasma sheaths; Spectrum analyzers; Laser induced fluorescence
Citation Formats
Hood, R., Baalrud, S. D., Merlino, R. L., and Skiff, F. Laser-induced fluorescence measurements of ion fluctuations in electron and ion presheaths. United States: N. p., 2020.
Web. doi:10.1063/1.5142014.
Hood, R., Baalrud, S. D., Merlino, R. L., & Skiff, F. Laser-induced fluorescence measurements of ion fluctuations in electron and ion presheaths. United States. https://doi.org/10.1063/1.5142014
Hood, R., Baalrud, S. D., Merlino, R. L., and Skiff, F. Tue .
"Laser-induced fluorescence measurements of ion fluctuations in electron and ion presheaths". United States. https://doi.org/10.1063/1.5142014. https://www.osti.gov/servlets/purl/1803000.
@article{osti_1803000,
title = {Laser-induced fluorescence measurements of ion fluctuations in electron and ion presheaths},
author = {Hood, R. and Baalrud, S. D. and Merlino, R. L. and Skiff, F.},
abstractNote = {Electrostatic flow-driven instabilities have been predicted in the presheath region of low-temperature plasmas for both ion and electron rich sheaths. The ion-acoustic fluctuations that arise from these instabilities can influence transport through an enhanced collision rate. In this work, ion fluctuation spectra were measured using laser-induced fluorescence (LIF) in the presheath region for both sheath polarities. Furthermore, the non-invasive nature of LIF compared to that of probes is particularly valuable for these measurements because the sheath and presheath around a probe may generate their own flow-driven instabilities, which obscure the measurement. Measurements were made using a recently implemented field programmable gate array-based system able to measure ion fluctuation spectra up to 1 MHz using a two-point correlation function technique. Narrow bandwidth ion fluctuations were observed near 0:46fpi (460 kHz) for both sheath polarities, where fpi is the ion plasma frequency. The observed fluctuations were significantly stronger in the electron sheath case and were observed over a larger volume of plasma. Fluctuations were measured in the ion sheath case at locations far enough from the sheath that linear theory predicts stability, suggesting that ion-acoustic instabilities generated in the relatively small unstable region near the boundary reflect from the sheath and perturb a much larger volume of the plasma. This is expected to affect probes with both ion and electron rich sheaths, meaning any dc biased probe may effectively act as an ion-acoustic wave antenna. These measurements are consistent with the recent theory and particle-in-cell results.},
doi = {10.1063/1.5142014},
journal = {Physics of Plasmas},
number = 5,
volume = 27,
place = {United States},
year = {Tue May 12 00:00:00 EDT 2020},
month = {Tue May 12 00:00:00 EDT 2020}
}
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Works referenced in this record:
The phase-space-resolved two-point correlation function of ion density fluctuations
journal, November 2005
- Diallo, Ahmed; Skiff, Frederick
- Physics of Plasmas, Vol. 12, Issue 11
Tokamak plasma diagnosis by electrical probes
journal, October 1994
- Matthews, G. F.
- Plasma Physics and Controlled Fusion, Vol. 36, Issue 10
Velocity space degrees of freedom of plasma fluctuations
journal, September 2017
- Mattingly, Sean; Skiff, Fred
- Physics of Plasmas, Vol. 24, Issue 9
Laser-induced-fluorescence observation of ion velocity distribution functions in a plasma sheath
journal, June 2006
- Claire, N.; Bachet, G.; Stroth, U.
- Physics of Plasmas, Vol. 13, Issue 6
Ion flow and sheath structure near positively biased electrodes
journal, November 2016
- Hood, R.; Scheiner, B.; Baalrud, S. D.
- Physics of Plasmas, Vol. 23, Issue 11
First Experimental Measurements of the Plasma Potential throughout the Presheath and Sheath at a Boundary in a Weakly Collisional Plasma
journal, September 2002
- Oksuz, L.; Hershkowitz, N.
- Physical Review Letters, Vol. 89, Issue 14
Theory of the electron sheath and presheath
journal, December 2015
- Scheiner, Brett; Baalrud, Scott D.; Yee, Benjamin T.
- Physics of Plasmas, Vol. 22, Issue 12
Principles of Plasma Discharges and Materials Processing
book, January 2005
- Lieberman, Michael A.; Lichtenberg, Allan J.
Analysis and comparison of ion-acoustic wave reflection using laser-induced fluorescence and Langmuir probes
journal, December 2018
- Berumen, J.; Skiff, F.
- Physics of Plasmas, Vol. 25, Issue 12
Kinetic theory of the presheath and the Bohm criterion
journal, March 2011
- Baalrud, S. D.; Hegna, C. C.
- Plasma Sources Science and Technology, Vol. 20, Issue 2
Sheaths: More complicated than you think
journal, May 2005
- Hershkowitz, Noah
- Physics of Plasmas, Vol. 12, Issue 5
Time-varying impedance of the sheath on a probe in an RF plasma
journal, August 2006
- Chen, Francis F.
- Plasma Sources Science and Technology, Vol. 15, Issue 4
Single frequency scanning laser as a plasma diagnostic
journal, March 1983
- Hill, David N.; Fornaca, Steven; Wickham, Michael G.
- Review of Scientific Instruments, Vol. 54, Issue 3
The influence of collisions on the plasma sheath transition
journal, November 1997
- Riemann, K. -U.
- Physics of Plasmas, Vol. 4, Issue 11
Measurement of deposition rate and ion energy distribution in a pulsed dc magnetron sputtering system using a retarding field analyzer with embedded quartz crystal microbalance
journal, April 2016
- Sharma, Shailesh; Gahan, David; Scullin, Paul
- Review of Scientific Instruments, Vol. 87, Issue 4
Mackenzie's Demon with instabilities
journal, October 2013
- Yip, Chi-Shung; Sheehan, J. P.; Hershkowitz, Noah
- Plasma Sources Science and Technology, Vol. 22, Issue 6
The Theory of Collectors in Gaseous Discharges
journal, October 1926
- Mott-Smith, H. M.; Langmuir, Irving
- Physical Review, Vol. 28, Issue 4
Reflection-Absorption Properties of Walls and Sheaths in the Propagation of Ion-Acoustic Waves
journal, January 1966
- Bertotti, B.
- Physics of Fluids, Vol. 9, Issue 7
Influence of ion streaming instabilities on transport near plasma boundaries
journal, February 2016
- Baalrud, Scott D.
- Plasma Sources Science and Technology, Vol. 25, Issue 2
FPGA based demodulation of laser induced fluorescence in plasmas
journal, April 2018
- Mattingly, Sean W.; Skiff, Fred
- Review of Scientific Instruments, Vol. 89, Issue 4
The Bohm criterion and sheath formation
journal, April 1991
- Riemann, K. -U
- Journal of Physics D: Applied Physics, Vol. 24, Issue 4
A Lagrangian model for laser-induced fluorescence and its application to measurements of plasma ion temperature and electrostatic waves
journal, January 2018
- Chu, F.; Skiff, F.
- Physics of Plasmas, Vol. 25, Issue 1
Electric probes for plasmas: The link between theory and instrument
journal, October 2002
- Demidov, V. I.; Ratynskaia, S. V.; Rypdal, K.
- Review of Scientific Instruments, Vol. 73, Issue 10
Reflection and absorption of ion-acoustic waves in a density gradient
journal, January 1978
- Ishihara, Osamu; Alexeff, Igor; Doucet, H. J.
- Physics of Fluids, Vol. 21, Issue 12
Verifying effects of instability enhanced ion–ion Coulomb collisions on ion velocity distribution functions near the sheath edge in low temperature plasmas
journal, December 2014
- Yip, Chi-Shung; Hershkowitz, Noah; Severn, Greg
- Plasma Sources Science and Technology, Vol. 24, Issue 1
Instability-Enhanced Collisional Effects and Langmuir’s Paradox
journal, June 2009
- Baalrud, S. D.; Callen, J. D.; Hegna, C. C.
- Physical Review Letters, Vol. 102, Issue 24
Local scrape-off layer control using biased electrodes in NSTX
journal, September 2009
- Zweben, S. J.; Maqueda, R. J.; Roquemore, A. L.
- Plasma Physics and Controlled Fusion, Vol. 51, Issue 10
Observation of coherent nonlinear interactions in the ion velocity distribution function
journal, November 2006
- Uzun-Kaymak, Ilker Ü.; Skiff, Frederick
- Physics of Plasmas, Vol. 13, Issue 11
Electron presheaths: the outsized influence of positive boundaries on plasmas
journal, January 2017
- Yee, B. T.; Scheiner, B.; Baalrud, S. D.
- Plasma Sources Science and Technology, Vol. 26, Issue 2
Global nonambipolar flow: Plasma confinement where all electrons are lost to one boundary and all positive ions to another boundary
journal, April 2007
- Baalrud, S. D.; Hershkowitz, N.; Longmier, B.
- Physics of Plasmas, Vol. 14, Issue 4
Ion-acoustic noise excited by positive probes
journal, April 1981
- Glanz, J.; Hershkowitz, N.
- Plasma Physics, Vol. 23, Issue 4
Particle-in-cell study of the ion-to-electron sheath transition
journal, August 2016
- Scheiner, Brett; Baalrud, Scott D.; Hopkins, Matthew M.
- Physics of Plasmas, Vol. 23, Issue 8
Convective Cells and Blob Control in a Simple Magnetized Plasma
journal, February 2012
- Theiler, C.; Furno, I.; Loizu, J.
- Physical Review Letters, Vol. 108, Issue 6
A comparison of emissive probe techniques for electric potential measurements in a complex plasma
journal, July 2011
- Sheehan, J. P.; Raitses, Y.; Hershkowitz, N.
- Physics of Plasmas, Vol. 18, Issue 7