Variable location channels to improve efficiency and precision for direct ∇Te measurements and high spatial resolution Te -profile measurements using electron cyclotron emission

Houshmandyar, S.; Austin, M. E.; Brookman, M. W.; Liu, Y.; Rowan, W. L.; Zhao, H.

doi:10.1063/1.5035429

Title: Variable location channels to improve efficiency and precision for direct ∇T_e measurements and high spatial resolution T_e -profile measurements using electron cyclotron emission

Abstract

Electron cyclotron emission (ECE) diagnostics that use variable location channels based on yttrium iron garnet (YIG) bandpass filters improve the precision and the efficiency of measurements of electron temperature (T_e) profiles and fluctuations (δT_e). These variable frequency filters were substituted for fixed frequency filters in the intermediate frequency section to achieve the required higher resolution over a target radial range, just before the experiment. In this paper, we present the proof-of-principle for high temporal resolution measurement of the electron temperature gradient, via real-time slewing of a YIG filter for relocation of an ECE channel during a long pulse. The key component is the application of YIG tunable filters with their narrow bandwidth and capability for a high slew rate of their center frequency. This application permits fast relocation of the ECE channels for direct measurement of the gradient and close spacing of channels to investigate the magnetic island’s dynamic behavior.

Authors:

^[1]; Austin, M. E. ^[1];

^[2];

^[3];

^[1]; Zhao, H. ^[4]

Univ. of Texas, Austin, TX (United States)
Univ. of Texas, Austin, TX (United States); General Atomics, San Diego, CA (United States)
Chinese Academy of Sciences (CAS), Hefei (China)
Univ. of Texas, Austin, TX (United States); Chinese Academy of Sciences (CAS), Hefei (China)

Publication Date:: Mon Aug 27 00:00:00 EDT 2018

Research Org.:: Univ. of Texas, Austin, TX (United States)

Sponsoring Org.:: USDOE Office of Science (SC), Fusion Energy Sciences (FES)

OSTI Identifier:: 1610389

Alternate Identifier(s):: OSTI ID: 1466871

Grant/Contract Number:: FG02-97ER54415; SC0010500

Resource Type:: Accepted Manuscript

Journal Name:: Review of Scientific Instruments

Additional Journal Information:: Journal Volume: 89; Journal Issue: 10; Journal ID: ISSN 0034-6748

Publisher:: American Institute of Physics (AIP)

Country of Publication:: United States

Language:: English

Subject:: 71 CLASSICAL AND QUANTUM MECHANICS, GENERAL PHYSICS; 47 OTHER INSTRUMENTATION; instruments & instrumentation; physics

Citation Formats


                    Houshmandyar, S., Austin, M. E., Brookman, M. W., Liu, Y., Rowan, W. L., and Zhao, H. Variable location channels to improve efficiency and precision for direct ∇Te measurements and high spatial resolution Te -profile measurements using electron cyclotron emission.  United States: N. p., 2018. 
Web.  doi:10.1063/1.5035429.

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                    Houshmandyar, S., Austin, M. E., Brookman, M. W., Liu, Y., Rowan, W. L., & Zhao, H. Variable location channels to improve efficiency and precision for direct ∇Te measurements and high spatial resolution Te -profile measurements using electron cyclotron emission.  United States.  https://doi.org/10.1063/1.5035429

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                    Houshmandyar, S., Austin, M. E., Brookman, M. W., Liu, Y., Rowan, W. L., and Zhao, H. Mon .  
"Variable location channels to improve efficiency and precision for direct ∇Te measurements and high spatial resolution Te -profile measurements using electron cyclotron emission".  United States.  https://doi.org/10.1063/1.5035429.  https://www.osti.gov/servlets/purl/1610389.

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@article{osti_1610389,

  title        = {Variable location channels to improve efficiency and precision for direct ∇Te measurements and high spatial resolution Te -profile measurements using electron cyclotron emission},

  author       = {Houshmandyar, S. and Austin, M. E. and Brookman, M. W. and Liu, Y. and Rowan, W. L. and Zhao, H.},

  abstractNote = {Electron cyclotron emission (ECE) diagnostics that use variable location channels based on yttrium iron garnet (YIG) bandpass filters improve the precision and the efficiency of measurements of electron temperature (Te) profiles and fluctuations (δTe). These variable frequency filters were substituted for fixed frequency filters in the intermediate frequency section to achieve the required higher resolution over a target radial range, just before the experiment. In this paper, we present the proof-of-principle for high temporal resolution measurement of the electron temperature gradient, via real-time slewing of a YIG filter for relocation of an ECE channel during a long pulse. The key component is the application of YIG tunable filters with their narrow bandwidth and capability for a high slew rate of their center frequency. This application permits fast relocation of the ECE channels for direct measurement of the gradient and close spacing of channels to investigate the magnetic island’s dynamic behavior.},

  doi          = {10.1063/1.5035429},

  journal      = {Review of Scientific Instruments},

  number       = 10,

  volume       = 89,

  place        = {United States},

  year         = {Mon Aug 27 00:00:00 EDT 2018},

  month        = {Mon Aug 27 00:00:00 EDT 2018}

}

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Works referenced in this record:

Temperature gradient scale length measurement: A high accuracy application of electron cyclotron emission without calibration
journal, July 2016

Houshmandyar, S.; Yang, Z. J.; Phillips, P. E.
Review of Scientific Instruments, Vol. 87, Issue 11
DOI: 10.1063/1.4955297

The effect of triangularity on fluctuations in a tokamak plasma
journal, December 2017

Fontana, M.; Porte, L.; Coda, S.
Nuclear Fusion, Vol. 58, Issue 2
DOI: 10.1088/1741-4326/aa98f4

Correlation electron cyclotron emission diagnostic in TCV
journal, August 2017

Fontana, M.; Porte, L.; Molina Cabrera, P.
Review of Scientific Instruments, Vol. 88, Issue 8
DOI: 10.1063/1.4997075

High spatial resolution upgrade of the electron cyclotron emission radiometer for the DIII-D tokamak
journal, November 2014

Truong, D. D.; Austin, M. E.
Review of Scientific Instruments, Vol. 85, Issue 11
DOI: 10.1063/1.4889737

Electron critical gradient scale length measurements of ICRF heated L-mode plasmas at Alcator C-Mod tokamak
journal, April 2018

Houshmandyar, S.; Hatch, D. R.; Horton, C. W.
Physics of Plasmas, Vol. 25, Issue 4
DOI: 10.1063/1.5022180

Works referencing / citing this record:

Upgrade of the ECE diagnostic on EAST
journal, October 2018

Zhao, Hailin; Zhou, Tianfu; Liu, Yong
Review of Scientific Instruments, Vol. 89, Issue 10
DOI: 10.1063/1.5035452

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Title: Variable location channels to improve efficiency and precision for direct ∇Te measurements and high spatial resolution Te -profile measurements using electron cyclotron emission

Abstract

Citation Formats

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Title: Variable location channels to improve efficiency and precision for direct ∇T_e measurements and high spatial resolution T_e -profile measurements using electron cyclotron emission

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journal, July 2016

The effect of triangularity on fluctuations in a tokamak plasma
journal, December 2017

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journal, August 2017

High spatial resolution upgrade of the electron cyclotron emission radiometer for the DIII-D tokamak
journal, November 2014

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journal, April 2018

Upgrade of the ECE diagnostic on EAST
journal, October 2018