Utilization of O-X-B mode conversion of 28 GHz microwaves to heat core electrons in the upgraded Proto-MPEX

Biewer, T. M.; Lau, C.; Bigelow, T. S.; Caneses, J. F.; Caughman, J. B.  O.; Goulding, R. H.; Kafle, N.; Kaufman, M. C.; Rapp, J.

doi:10.1063/1.5093321

Title: Utilization of O-X-B mode conversion of 28 GHz microwaves to heat core electrons in the upgraded Proto-MPEX

Abstract

The magnetic geometry of the Prototype Material Plasma Exposure eXperiment (Proto-MPEX) was recently altered to enable more effective utilization of 28 GHz microwave auxiliary power, specifically: (1) to heat plasma electrons in the radial core of the device and (2) to deliver the heated plasma to the target plate of the device. To achieve this goal, the microwave launcher geometry and placement were significantly re-engineered, guided by previous experimental results and computational modeling. The core electron temperature in the launcher region is observed to increase from 3 eV to 11 eV with 30 kW of auxiliary power after the improvements, and an increase from 3 eV to 6 eV is concurrently measured in the target region (~1 m from the launcher) at electron density above O-mode cutoff. Radially resolved measurements in the launcher region exhibit a strong dependence on the magnetic geometry. The conclusions of a magnetic field scan reinforce the effectiveness of the intended O-X-B mode conversion scenario that is currently planned for microwave heating of the Material Plasma Exposure eXperiment (MPEX).

Authors:

^[1];

^[2];

^[1];

^[1]

Oak Ridge National Laboratory (ORNL), Oak Ridge, TN (United States)
Oak Ridge National Laboratory (ORNL), Oak Ridge, TN (United States); Univ. of Tennessee, Knoxville, TN (United States)

Publication Date:: Mon May 20 00:00:00 EDT 2019

Research Org.:: Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States)

Sponsoring Org.:: USDOE Office of Science (SC)

Contributing Org.:: Proto-MPEX Team

OSTI Identifier:: 1515670

Alternate Identifier(s):: OSTI ID: 1514744

Grant/Contract Number:: AC05-00OR22725

Resource Type:: Accepted Manuscript

Journal Name:: Physics of Plasmas

Additional Journal Information:: Journal Volume: 26; 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

Citation Formats


                    Biewer, T. M., Lau, C., Bigelow, T. S., Caneses, J. F., Caughman, J. B.  O., Goulding, R. H., Kafle, N., Kaufman, M. C., and Rapp, J. Utilization of O-X-B mode conversion of 28 GHz microwaves to heat core electrons in the upgraded Proto-MPEX.  United States: N. p., 2019. 
Web.  doi:10.1063/1.5093321.

Copy to clipboard


                    Biewer, T. M., Lau, C., Bigelow, T. S., Caneses, J. F., Caughman, J. B.  O., Goulding, R. H., Kafle, N., Kaufman, M. C., & Rapp, J. Utilization of O-X-B mode conversion of 28 GHz microwaves to heat core electrons in the upgraded Proto-MPEX.  United States.  https://doi.org/10.1063/1.5093321

Copy to clipboard


                    Biewer, T. M., Lau, C., Bigelow, T. S., Caneses, J. F., Caughman, J. B.  O., Goulding, R. H., Kafle, N., Kaufman, M. C., and Rapp, J. Mon .  
"Utilization of O-X-B mode conversion of 28 GHz microwaves to heat core electrons in the upgraded Proto-MPEX".  United States.  https://doi.org/10.1063/1.5093321.  https://www.osti.gov/servlets/purl/1515670.

Copy to clipboard


                    
@article{osti_1515670,

  title        = {Utilization of O-X-B mode conversion of 28 GHz microwaves to heat core electrons in the upgraded Proto-MPEX},

  author       = {Biewer, T. M. and Lau, C. and Bigelow, T. S. and Caneses, J. F. and Caughman, J. B.  O. and Goulding, R. H. and Kafle, N. and Kaufman, M. C. and Rapp, J.},

  abstractNote = {The magnetic geometry of the Prototype Material Plasma Exposure eXperiment (Proto-MPEX) was recently altered to enable more effective utilization of 28 GHz microwave auxiliary power, specifically: (1) to heat plasma electrons in the radial core of the device and (2) to deliver the heated plasma to the target plate of the device. To achieve this goal, the microwave launcher geometry and placement were significantly re-engineered, guided by previous experimental results and computational modeling. The core electron temperature in the launcher region is observed to increase from 3 eV to 11 eV with 30 kW of auxiliary power after the improvements, and an increase from 3 eV to 6 eV is concurrently measured in the target region (~1 m from the launcher) at electron density above O-mode cutoff. Radially resolved measurements in the launcher region exhibit a strong dependence on the magnetic geometry. The conclusions of a magnetic field scan reinforce the effectiveness of the intended O-X-B mode conversion scenario that is currently planned for microwave heating of the Material Plasma Exposure eXperiment (MPEX).},

  doi          = {10.1063/1.5093321},

  journal      = {Physics of Plasmas},

  number       = 5,

  volume       = 26,

  place        = {United States},

  year         = {Mon May 20 00:00:00 EDT 2019},

  month        = {Mon May 20 00:00:00 EDT 2019}

}

Copy to clipboard

Journal Article:

Free Publicly Available Full Text

Accepted Manuscript (Publisher)

Accepted Manuscript (DOE)

Publisher's Version of Record

https://doi.org/10.1063/1.5093321

Other availability

Search WorldCat to find libraries that may hold this journal

Citation Metrics:

Cited by: 12 works

Citation information provided by
Web of Science

Save / Share:

Export Metadata

Save to My Library

Works referenced in this record:

Developing the science and technology for the Material Plasma Exposure eXperiment
journal, July 2017

Rapp, J.; Biewer, T. M.; Bigelow, T. S.
Nuclear Fusion, Vol. 57, Issue 11
DOI: 10.1088/1741-4326/aa7b1c

Operational domain of Proto-MPEX
journal, November 2018

Rapp, Juergen; Beers, Clyde; Biewer, Theodore
Fusion Engineering and Design, Vol. 136
DOI: 10.1016/j.fusengdes.2018.03.064

Transition from Pastukhov to collisional confinement in a magnetic and electrostatic well
journal, August 1980

Rognlien, T. D.; Cutler, T. A.
Nuclear Fusion, Vol. 20, Issue 8
DOI: 10.1088/0029-5515/20/8/007

Progress in the Development of a High Power Helicon Plasma Source for the Materials Plasma Exposure Experiment
journal, August 2017

Goulding, R. H.; Caughman, J. B. O.; Rapp, J.
Fusion Science and Technology, Vol. 72, Issue 4
DOI: 10.1080/15361055.2017.1352429

Heat flux estimates of power balance on Proto-MPEX with IR imaging
journal, August 2016

Showers, M.; Biewer, T. M.; Caughman, J. B. O.
Review of Scientific Instruments, Vol. 87, Issue 11
DOI: 10.1063/1.4959953

Power accounting of plasma discharges in the linear device Proto-MPEX
journal, April 2018

Showers, M.; Piotrowicz, P. A.; Beers, C. J.
Plasma Physics and Controlled Fusion, Vol. 60, Issue 6
DOI: 10.1088/1361-6587/aab7c8

An electron Bernstein wave heating scheme for the Proto-MPEX linear device
journal, July 2018

Diem, S. J.; Green, D. L.; Harvey, R. W.
Physics of Plasmas, Vol. 25, Issue 7
DOI: 10.1063/1.5033334

Characterization of the helicon plasma flux to the target of Proto-MPEX
journal, January 2019

Beers, C. J.; Lindquist, E. G.; Biewer, T. M.
Fusion Engineering and Design, Vol. 138
DOI: 10.1016/j.fusengdes.2018.11.056

Mode Conversion and Local Heating below the Second Electron Cyclotron Harmonic
journal, December 1981

Sugai, H.
Physical Review Letters, Vol. 47, Issue 26
DOI: 10.1103/PhysRevLett.47.1899

Observations of electron heating during 28 GHz microwave power application in proto-MPEX
journal, February 2018

Biewer, T. M.; Bigelow, T. S.; Caneses, J. F.
Physics of Plasmas, Vol. 25, Issue 2
DOI: 10.1063/1.5018479

Direct measurement of the transition from edge to core power coupling in a light-ion helicon source
journal, May 2018

Piotrowicz, P. A.; Caneses, J. F.; Showers, M. A.
Physics of Plasmas, Vol. 25, Issue 5
DOI: 10.1063/1.5023924

Resonant and Nonresonant Electron Cyclotron Heating at Densities above the Plasma Cutoff by O-X-B Mode Conversion at the W7-As Stellarator
journal, May 1997

Laqua, H. P.; Erckmann, V.; Hartfuß, H. J.
Physical Review Letters, Vol. 78, Issue 18
DOI: 10.1103/PhysRevLett.78.3467

RF compensation of double Langmuir probes: modelling and experiment
journal, May 2015

Caneses, Juan F.; Blackwell, Boyd
Plasma Sources Science and Technology, Vol. 24, Issue 3
DOI: 10.1088/0963-0252/24/3/035024

The Development of the Material Plasma Exposure Experiment
journal, December 2016

Rapp, Juergen; Biewer, T. M.; Bigelow, T. S.
IEEE Transactions on Plasma Science, Vol. 44, Issue 12
DOI: 10.1109/TPS.2016.2628326

Differential pumping requirements for the light-ion helicon source and heating systems of Proto-MPEX
journal, August 2018

Caneses, J. F.; Piotrowicz, P. A.; Biewer, T. M.
Physics of Plasmas, Vol. 25, Issue 8
DOI: 10.1063/1.5001519

Plasma source development for fusion-relevant material testing
journal, May 2017

Caughman, John B. O.; Goulding, Richard H.; Biewer, Theodore M.
Journal of Vacuum Science & Technology A: Vacuum, Surfaces, and Films, Vol. 35, Issue 3
DOI: 10.1116/1.4982664

Electron Bernstein wave generation in a linear plasma system
journal, October 2004

Yadav, Vipin K.; Bora, D.
Physics of Plasmas, Vol. 11, Issue 10
DOI: 10.1063/1.1784787

Similar Records in DOE PAGES and OSTI.GOV collections:

Ion cyclotron heating at high plasma density in Proto-MPEX

Journal Article Goulding, Richard H. ; Lau, Cornwall H. ; Piotrowicz, Pawel A. ; ... - Physics of Plasmas

The physics of ion cyclotron heating (ICH) relevant to the steady-state linear machine MPEX (Material Plasma Exposure eXperiment) has been explored in its predecessor, short-pulse device: Proto-MPEX. MPEX will utilize fundamental ICH to increase heat flux at the target and produce ion temperatures and velocity distributions with improved fidelity to those found in a tokamak divertor region, in comparison to those produced by substrate biasing. In the experiments on Proto-MPEX described here, bulk ion temperatures up to ~15 eV have been achieved with 20 kW net ICH power at 6.5 MHz, using ICH heating of a deuterium plasma produced by a helicon plasma source. The heat flux at the target has been observed to increase throughout the plasma cross section, including in the core region. Coremore »« less
https://doi.org/10.1063/5.0122915

Full Text Available
Plasma flow measurements in the Prototype-Material Plasma Exposure eXperiment (Proto-MPEX) and comparison with B2.5-Eirene modeling

Journal Article Kafle, Nischal ; Owen, Larry W. ; Caneses Marin, Juan ; ... - Physics of Plasmas

The Prototype Material Plasma Exposure eXperiment (Proto-MPEX) at Oak Ridge National Laboratory is a linear plasma device that combines a helicon plasma source with additional microwave and radio frequency heating to deliver high plasma heat and particle fluxes to a target. Double Langmuir probes and Thomson scattering are being used to measure local electron temperature and density at various radial and axial locations. A recently constructed Mach-double probe provides the added capability of simultaneously measuring electron temperatures (T_e), electron densities (n_e), and Mach numbers (M). With this diagnostic, it is possible to infer the plasma flow, particle flux, and heatmore »« less
Cited by 11
https://doi.org/10.1063/1.5019266

Full Text Available
Analysing the effects of heating and gas puffing in Proto-MPEX helicon and auxiliary heated plasmas

Journal Article Islam, Md Shahinul ; Lore, Jeremy D. ; Lau, Cornwall ; ... - Plasma Physics and Controlled Fusion

The Material Plasma Exposure Experiment (MPEX) is being constructed at Oak Ridge National Laboratory to investigate critical fusion reactor issues, such as plasma–material interactions (PMIs) under reactor-relevant conditions and time scales. The linear device Proto-MPEX was used as a test bed to address anticipated research and development issues associated with heating scenarios and establish the physics basis for MPEX. The SOLPS-ITER code suite has been applied to understand plasma and neutral transport in Proto-MPEX and to increase confidence in predictive simulations for MPEX. Coupling between COMSOL and SOLPS is performed to implement a 2D electron heating profile of the helicon source. The simulations show reasonable agreement with the experimental data for plasma with helicon and auxiliary electron cyclotron heating (ECH). Both Bohm and constant diffusion (Dmore »« less
https://doi.org/10.1088/1361-6587/ace793

Full Text Available
Physical and technical basis of Materials Plasma Exposure eXperiment from modeling and Proto-MPEX results ^*

Journal Article Lau, C. ; Biewer, T. M. ; Bigelow, T. S. ; ... - Nuclear Fusion

Abstract The Materials Plasma Exposure eXperiment (MPEX) is a steady-state linear plasma device that will address plasma-material interaction (PMI) science and enable testing of fusion reactor-relevant divertor plasma-facing materials. The MPEX source concept consists of a helicon plasma source to generate the plasma, electron cyclotron heating (ECH) for electron heating, and ion cyclotron heating (ICH) for ion heating. The MPEX source plasma is then transported axially to the PMI material target region to test material samples in fusion reactor-relevant divertor conditions. This paper will summarize the physical and technical basis of MPEX. The paper will first define the MPEX parametersmore »« less
https://doi.org/10.1088/1741-4326/acc2d1
An electron Bernstein wave heating scheme for the Proto-MPEX linear device

Journal Article Diem, Stephanie ; Green, David ; Harvey, R.W. ; ... - Physics of Plasmas

Linear plasma devices, such as the Prototype Material Plasma Exposure eXperiment (Proto-MPEX), are an economic method to study plasma-material interactions under high heat and particle fluxes. The Proto-MPEX device at Oak Ridge National Laboratory is a high-density helicon plasma generator with additional resonant electron heating to study plasma-material interactions in ITER-like conditions. Here, we present modeling results of an electron Bernstein wave (EBW) heating scheme for this device using a microwave-based system. A 28 GHz injection system is available to provide power levels up to 100 kW injected into low electron temperature and high electron density plasmas. A modified versionmore »« less
Cited by 18
https://doi.org/10.1063/1.5033334

Full Text Available

Similar Records

Title: Utilization of O-X-B mode conversion of 28 GHz microwaves to heat core electrons in the upgraded Proto-MPEX

Abstract

Citation Formats

Developing the science and technology for the Material Plasma Exposure eXperiment journal, July 2017

Operational domain of Proto-MPEX journal, November 2018

Transition from Pastukhov to collisional confinement in a magnetic and electrostatic well journal, August 1980

Progress in the Development of a High Power Helicon Plasma Source for the Materials Plasma Exposure Experiment journal, August 2017

Heat flux estimates of power balance on Proto-MPEX with IR imaging journal, August 2016

Power accounting of plasma discharges in the linear device Proto-MPEX journal, April 2018

An electron Bernstein wave heating scheme for the Proto-MPEX linear device journal, July 2018

Characterization of the helicon plasma flux to the target of Proto-MPEX journal, January 2019

Mode Conversion and Local Heating below the Second Electron Cyclotron Harmonic journal, December 1981

Observations of electron heating during 28 GHz microwave power application in proto-MPEX journal, February 2018

Direct measurement of the transition from edge to core power coupling in a light-ion helicon source journal, May 2018

Resonant and Nonresonant Electron Cyclotron Heating at Densities above the Plasma Cutoff by O-X-B Mode Conversion at the W7-As Stellarator journal, May 1997

RF compensation of double Langmuir probes: modelling and experiment journal, May 2015

The Development of the Material Plasma Exposure Experiment journal, December 2016

Differential pumping requirements for the light-ion helicon source and heating systems of Proto-MPEX journal, August 2018

Plasma source development for fusion-relevant material testing journal, May 2017

Electron Bernstein wave generation in a linear plasma system journal, October 2004

Developing the science and technology for the Material Plasma Exposure eXperiment
journal, July 2017

Operational domain of Proto-MPEX
journal, November 2018

Transition from Pastukhov to collisional confinement in a magnetic and electrostatic well
journal, August 1980

Progress in the Development of a High Power Helicon Plasma Source for the Materials Plasma Exposure Experiment
journal, August 2017

Heat flux estimates of power balance on Proto-MPEX with IR imaging
journal, August 2016

Power accounting of plasma discharges in the linear device Proto-MPEX
journal, April 2018

An electron Bernstein wave heating scheme for the Proto-MPEX linear device
journal, July 2018

Characterization of the helicon plasma flux to the target of Proto-MPEX
journal, January 2019

Mode Conversion and Local Heating below the Second Electron Cyclotron Harmonic
journal, December 1981

Observations of electron heating during 28 GHz microwave power application in proto-MPEX
journal, February 2018

Direct measurement of the transition from edge to core power coupling in a light-ion helicon source
journal, May 2018

Resonant and Nonresonant Electron Cyclotron Heating at Densities above the Plasma Cutoff by O-X-B Mode Conversion at the W7-As Stellarator
journal, May 1997

RF compensation of double Langmuir probes: modelling and experiment
journal, May 2015

The Development of the Material Plasma Exposure Experiment
journal, December 2016

Differential pumping requirements for the light-ion helicon source and heating systems of Proto-MPEX
journal, August 2018

Plasma source development for fusion-relevant material testing
journal, May 2017

Electron Bernstein wave generation in a linear plasma system
journal, October 2004