A heterodyne dispersion interferometer for wide bandwidth density measurements on DIII-D

Akiyama, T.; Van Zeeland, M. A.; Boivin, R. L.; Carlstrom, T. N.; Chavez, J. A.; Muscatello, C. M.; O’Neill, R.; Vasquez, J.; Watkins, M.; Martin, W.; Colio, A.; Finkenthal, D. K.; Brower, D. L.; Chen, J.; Ding, W. X.; Perry, M.

doi:10.1063/1.5037997

Title: A heterodyne dispersion interferometer for wide bandwidth density measurements on DIII-D

Abstract

In order to improve both the density and particularly the temporal resolution beyond previous dispersion interferometers (DIs), a heterodyne technique based on an acousto-optic (AO) cell has been added to the DI. A 40 MHz drive frequency for the AO cell allows density fluctuation measurements into the MHz range. A CO₂ laser-based heterodyne DI (HDI) installed on DIII-D has demonstrated that the HDI is capable of tracking the density evolution throughout DIII-D discharges, including disruption events and other rapid transient phenomena. The data also show good agreement with independent density measurements obtained with the existing DIII-D two-color interferometer. The HDI line-integrated density resolution sampled over a 1 s interval is ~9 × 10¹⁷ m^-2. Density fluctuations induced by MHD instabilities are also successfully measured by the HDI.

Authors:

Akiyama, T. ^[1]; Van Zeeland, M. A. ^[2]; Boivin, R. L. ^[2];

^[2]; Chavez, J. A. ^[2];

^[2]; O’Neill, R. ^[2]; Vasquez, J. ^[2]; Watkins, M. ^[2]; Martin, W. ^[2]; Colio, A. ^[3]; Finkenthal, D. K. ^[3]; Brower, D. L. ^[4];

^[4]; Ding, W. X. ^[4]; Perry, M. ^[5]

National Inst. for Fusion Science, Gifu (Japan)
General Atomics, San Diego, CA (United States)
Palomar College, San Marcos, CA (United States)
Univ. of California, Los Angeles, CA (United States)
California State Univ., San Marcos, CA (United States)

Publication Date:: Tue Jul 24 00:00:00 EDT 2018

Research Org.:: General Atomics, San Diego, CA (United States); Tech-X Corporation, Boulder, CO (United States); Princeton Univ., NJ (United States)

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

OSTI Identifier:: 1609191

Alternate Identifier(s):: OSTI ID: 1461569

Grant/Contract Number:: FC02-04ER54698; FC02-06ER54875; FC02-08ER54972; AC02-09CH11466

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; instruments & instrumentation; physics

Citation Formats


                    Akiyama, T., Van Zeeland, M. A., Boivin, R. L., Carlstrom, T. N., Chavez, J. A., Muscatello, C. M., O’Neill, R., Vasquez, J., Watkins, M., Martin, W., Colio, A., Finkenthal, D. K., Brower, D. L., Chen, J., Ding, W. X., and Perry, M. A heterodyne dispersion interferometer for wide bandwidth density measurements on DIII-D.  United States: N. p., 2018. 
Web.  doi:10.1063/1.5037997.

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                    Akiyama, T., Van Zeeland, M. A., Boivin, R. L., Carlstrom, T. N., Chavez, J. A., Muscatello, C. M., O’Neill, R., Vasquez, J., Watkins, M., Martin, W., Colio, A., Finkenthal, D. K., Brower, D. L., Chen, J., Ding, W. X., & Perry, M. A heterodyne dispersion interferometer for wide bandwidth density measurements on DIII-D.  United States.  https://doi.org/10.1063/1.5037997

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                    Akiyama, T., Van Zeeland, M. A., Boivin, R. L., Carlstrom, T. N., Chavez, J. A., Muscatello, C. M., O’Neill, R., Vasquez, J., Watkins, M., Martin, W., Colio, A., Finkenthal, D. K., Brower, D. L., Chen, J., Ding, W. X., and Perry, M. Tue .  
"A heterodyne dispersion interferometer for wide bandwidth density measurements on DIII-D".  United States.  https://doi.org/10.1063/1.5037997.  https://www.osti.gov/servlets/purl/1609191.

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@article{osti_1609191,

  title        = {A heterodyne dispersion interferometer for wide bandwidth density measurements on DIII-D},

  author       = {Akiyama, T. and Van Zeeland, M. A. and Boivin, R. L. and Carlstrom, T. N. and Chavez, J. A. and Muscatello, C. M. and O’Neill, R. and Vasquez, J. and Watkins, M. and Martin, W. and Colio, A. and Finkenthal, D. K. and Brower, D. L. and Chen, J. and Ding, W. X. and Perry, M.},

  abstractNote = {In order to improve both the density and particularly the temporal resolution beyond previous dispersion interferometers (DIs), a heterodyne technique based on an acousto-optic (AO) cell has been added to the DI. A 40 MHz drive frequency for the AO cell allows density fluctuation measurements into the MHz range. A CO2 laser-based heterodyne DI (HDI) installed on DIII-D has demonstrated that the HDI is capable of tracking the density evolution throughout DIII-D discharges, including disruption events and other rapid transient phenomena. The data also show good agreement with independent density measurements obtained with the existing DIII-D two-color interferometer. The HDI line-integrated density resolution sampled over a 1 s interval is ~9 × 1017 m-2. Density fluctuations induced by MHD instabilities are also successfully measured by the HDI.},

  doi          = {10.1063/1.5037997},

  journal      = {Review of Scientific Instruments},

  number       = 10,

  volume       = 89,

  place        = {United States},

  year         = {Tue Jul 24 00:00:00 EDT 2018},

  month        = {Tue Jul 24 00:00:00 EDT 2018}

}

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Works referenced in this record:

Two-dimensional straightness measurement based on optical knife-edge sensing
journal, September 2017

Wang, Chen; Zhong, Fenghe; Ellis, Jonathan D.
Review of Scientific Instruments, Vol. 88, Issue 9
DOI: 10.1063/1.5002711

Design of a dispersion interferometer combined with a polarimeter to increase the electron density measurement reliability on ITER
journal, September 2016

Akiyama, T.; Sirinelli, A.; Watts, C.
Review of Scientific Instruments, Vol. 87, Issue 11
DOI: 10.1063/1.4962050

Dispersion interferometer using modulation amplitudes on LHD (invited)
journal, November 2014

Akiyama, T.; Yasuhara, R.; Kawahata, K.
Review of Scientific Instruments, Vol. 85, Issue 11
DOI: 10.1063/1.4886777

Bench testing of a heterodyne CO ₂ laser dispersion interferometer for high temporal resolution plasma density measurements
journal, December 2016

Akiyama, T.; Van Zeeland, M. A.; Boivin, R. L.
Review of Scientific Instruments, Vol. 87, Issue 12
DOI: 10.1063/1.4969055

Dispersion interferometer for controlled fusion devices
journal, April 1993

Drachev, V. P.; Krasnikov, Yu. I.; Bagryansky, P. A.
Review of Scientific Instruments, Vol. 64, Issue 4
DOI: 10.1063/1.1144170

Tests of a two-color interferometer and polarimeter for ITER density measurements
journal, October 2017

Van Zeeland, M. A.; Carlstrom, T. N.; Finkenthal, D. K.
Plasma Physics and Controlled Fusion, Vol. 59, Issue 12
DOI: 10.1088/1361-6587/aa8c49

Tests of a full-scale ITER toroidal interferometer and polarimeter (TIP) prototype on the DIII-D tokamak (invited)
journal, October 2018

Van Zeeland, M. A.; Carlstrom, T. N.; Finkenthal, D. K.
Review of Scientific Instruments, Vol. 89, Issue 10
DOI: 10.1063/1.5037461

Dispersion interferometer based on a CO2 laser for TEXTOR and burning plasma experiments
journal, May 2006

Bagryansky, P. A.; Khilchenko, A. D.; Kvashnin, A. N.
Review of Scientific Instruments, Vol. 77, Issue 5
DOI: 10.1063/1.2202922

Works referencing / citing this record:

Innovations in Technology and Science R&D for ITER
journal, January 2019

Campbell, David J.; Akiyama, Tsuyoshi; Barnsley, Robin
Journal of Fusion Energy, Vol. 38, Issue 1
DOI: 10.1007/s10894-018-0187-9

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Title: A heterodyne dispersion interferometer for wide bandwidth density measurements on DIII-D

Abstract

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