Linear servomotor probe drive system with real-time self-adaptive position control for the Alcator C-Mod tokamak

Brunner, D.; Kuang, A. Q.; LaBombard, B.; Burke, W.

doi:10.7910/DVN/I5SQMY

Title: Linear servomotor probe drive system with real-time self-adaptive position control for the Alcator C-Mod tokamak

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Abstract

A new servomotor drive system has been developed for the horizontal reciprocating probe on the Alcator C-Mod tokamak. Real-time measurements of plasma temperature and density—through use of a mirror Langmuir probe bias system—combined with a commercial linear servomotor and controller enables self-adaptive position control. Probe surface temperature and its rate of change are computed in real time and used to control probe insertion depth. It is found that a universal trigger threshold can be defined in terms of these two parameters; if the probe is triggered to retract when crossing the trigger threshold, it will reach the same ultimate surface temperature, independent of velocity, acceleration, or scrape-off layer heat flux scale length. In addition to controlling the probe motion, the controller is used to monitor and control all aspects of the integrated probe drive system.

Authors:

Brunner, D.; Kuang, A. Q.; LaBombard, B.; Burke, W.

OSTI

Publication Date:: Tue Oct 16 00:00:00 EDT 2018

DOE Contract Number:: FC02-99ER54512

Research Org.:: Massachusetts Inst. of Technology (MIT), Cambridge, MA (United States). Plasma Science and Fusion Center

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

Subject:: 70 PLASMA PHYSICS AND FUSION TECHNOLOGY

OSTI Identifier:: 1880103

DOI:: https://doi.org/10.7910/DVN/I5SQMY

Citation Formats


                    Brunner, D., Kuang, A. Q., LaBombard, B., and Burke, W. Linear servomotor probe drive system with real-time self-adaptive position control for the Alcator C-Mod tokamak.  United States: N. p., 2018. 
        Web.  doi:10.7910/DVN/I5SQMY.

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                    Brunner, D., Kuang, A. Q., LaBombard, B., & Burke, W. Linear servomotor probe drive system with real-time self-adaptive position control for the Alcator C-Mod tokamak.  United States.  doi:https://doi.org/10.7910/DVN/I5SQMY

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                    Brunner, D., Kuang, A. Q., LaBombard, B., and Burke, W. 2018.  
"Linear servomotor probe drive system with real-time self-adaptive position control for the Alcator C-Mod tokamak".  United States.  doi:https://doi.org/10.7910/DVN/I5SQMY.  https://www.osti.gov/servlets/purl/1880103. Pub date:Tue Oct 16 00:00:00 EDT 2018

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@article{osti_1880103,

  title        = {Linear servomotor probe drive system with real-time self-adaptive position control for the Alcator C-Mod tokamak},

  author       = {Brunner, D. and Kuang, A. Q. and LaBombard, B. and Burke, W.},

  abstractNote = {A new servomotor drive system has been developed for the horizontal reciprocating probe on the Alcator C-Mod tokamak. Real-time measurements of plasma temperature and density—through use of a mirror Langmuir probe bias system—combined with a commercial linear servomotor and controller enables self-adaptive position control. Probe surface temperature and its rate of change are computed in real time and used to control probe insertion depth. It is found that a universal trigger threshold can be defined in terms of these two parameters; if the probe is triggered to retract when crossing the trigger threshold, it will reach the same ultimate surface temperature, independent of velocity, acceleration, or scrape-off layer heat flux scale length. In addition to controlling the probe motion, the controller is used to monitor and control all aspects of the integrated probe drive system.},

  doi          = {10.7910/DVN/I5SQMY},

  journal      = {},

  number       = ,

  volume       = ,

  place        = {United States},

  year         = {Tue Oct 16 00:00:00 EDT 2018},

  month        = {Tue Oct 16 00:00:00 EDT 2018}

}

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DOI: https://doi.org/10.7910/DVN/I5SQMY

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