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

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 enable 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. Finally, in addition to controlling the probe motion, the controller is used to monitor and control all aspects of the integrated probe drive system.

Authors:
ORCiD logo [1]; ORCiD logo [1];  [1];  [1]
  1. Massachusetts Inst. of Technology (MIT), Cambridge, MA (United States). Plasma Science and Fusion Center
Publication Date:
Research Org.:
Massachusetts Inst. of Technology (MIT), Cambridge, MA (United States)
Sponsoring Org.:
USDOE Office of Science (SC)
OSTI Identifier:
1474327
Alternate Identifier(s):
OSTI ID: 1367935
Grant/Contract Number:  
FC02-99ER54512
Resource Type:
Accepted Manuscript
Journal Name:
Review of Scientific Instruments
Additional Journal Information:
Journal Volume: 88; Journal Issue: 7; Journal ID: ISSN 0034-6748
Publisher:
American Institute of Physics (AIP)
Country of Publication:
United States
Language:
English
Subject:
70 PLASMA PHYSICS AND FUSION TECHNOLOGY

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., 2017. Web. doi:10.1063/1.4990043.
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. https://doi.org/10.1063/1.4990043
Brunner, D., Kuang, A. Q., LaBombard, B., and Burke, W. Wed . "Linear servomotor probe drive system with real-time self-adaptive position control for the Alcator C-Mod tokamak". United States. https://doi.org/10.1063/1.4990043. https://www.osti.gov/servlets/purl/1474327.
@article{osti_1474327,
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 enable 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. Finally, in addition to controlling the probe motion, the controller is used to monitor and control all aspects of the integrated probe drive system.},
doi = {10.1063/1.4990043},
journal = {Review of Scientific Instruments},
number = 7,
volume = 88,
place = {United States},
year = {Wed Jul 05 00:00:00 EDT 2017},
month = {Wed Jul 05 00:00:00 EDT 2017}
}

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Cited by: 9 works
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Works referenced in this record:

Fast scanning probe for the NSTX spherical tokamak
journal, December 2009

  • Boedo, J. A.; Crocker, N.; Chousal, L.
  • Review of Scientific Instruments, Vol. 80, Issue 12
  • DOI: 10.1063/1.3266065

Wall scanning probe for high-field side plasma measurements on Alcator C-Mod
journal, February 2009

  • Smick, Noah; LaBombard, Brian
  • Review of Scientific Instruments, Vol. 80, Issue 2
  • DOI: 10.1063/1.3069290

An ultrafast reciprocating probe
journal, September 2016

  • Liu, Wenbin; Tan, Yi; Wang, Wenhao
  • Review of Scientific Instruments, Vol. 87, Issue 11
  • DOI: 10.1063/1.4962060

Intermittent transport across the scrape-off layer: latest results from ASDEX Upgrade
journal, June 2013


Development of a high-speed, reciprocating electrostatic probe system for Hall thruster interrogation
journal, January 2000

  • Haas, James M.; Gallimore, Alec D.; McFall, Keith
  • Review of Scientific Instruments, Vol. 71, Issue 11
  • DOI: 10.1063/1.1318921

MDS plus data acquisition system
journal, January 1997

  • Stillerman, J. A.; Fredian, T. W.; Klare, K. A.
  • Review of Scientific Instruments, Vol. 68, Issue 1
  • DOI: 10.1063/1.1147719

Surface thermocouples for measurement of pulsed heat flux in the divertor of the Alcator C-Mod tokamak
journal, March 2012

  • Brunner, D.; LaBombard, B.
  • Review of Scientific Instruments, Vol. 83, Issue 3
  • DOI: 10.1063/1.3689770

Mirror Langmuir probe: A technique for real-time measurement of magnetized plasma conditions using a single Langmuir electrode
journal, July 2007

  • LaBombard, B.; Lyons, L.
  • Review of Scientific Instruments, Vol. 78, Issue 7
  • DOI: 10.1063/1.2754392

Fast reciprocating probe system on the EAST superconducting tokamak
journal, November 2010

  • Zhang, W.; Chang, J. F.; Wan, B. N.
  • Review of Scientific Instruments, Vol. 81, Issue 11
  • DOI: 10.1063/1.3499237

Electric Probes in Tokamaks: Experience in Tore Supra
journal, March 2011

  • Gunn, J. P.; Pascal, J. -Y.; Saint-Laurent, F.
  • Contributions to Plasma Physics, Vol. 51, Issue 2-3
  • DOI: 10.1002/ctpp.201000074

The effect of transient temporal pulse shape on surface temperature and tungsten damage
journal, August 2015


An assessment of ion temperature measurements in the boundary of the Alcator C-Mod tokamak and implications for ion fluid heat flux limiters
journal, July 2013


Scanning retarding field analyzer for plasma profile measurements in the boundary of the Alcator C-Mod tokamak
journal, March 2013

  • Brunner, D.; LaBombard, B.; Ochoukov, R.
  • Review of Scientific Instruments, Vol. 84, Issue 3
  • DOI: 10.1063/1.4793785

Magnetically driven filament probe
journal, May 2007

  • Schmid, A.; Herrmann, A.; Rohde, V.
  • Review of Scientific Instruments, Vol. 78, Issue 5
  • DOI: 10.1063/1.2735942

A magnetically driven reciprocating probe for tokamak scrape-off layer measurements
journal, December 2011

  • Gunn, J. P.; Pascal, J. -Y.
  • Review of Scientific Instruments, Vol. 82, Issue 12
  • DOI: 10.1063/1.3661128

A fast moving diagnostic system on the RFX experiment
journal, January 1999

  • Desideri, D.; Serianni, G.; Antoni, V.
  • Review of Scientific Instruments, Vol. 70, Issue 1
  • DOI: 10.1063/1.1149310

Plasma profiles and flows in the high-field side scrape-off layer in Alcator C-Mod
journal, March 2005


MDSplus objects—Python implementation
journal, July 2010


Feedback system for divertor impurity seeding based on real-time measurements of surface heat flux in the Alcator C-Mod tokamak
journal, February 2016

  • Brunner, D.; Burke, W.; Kuang, A. Q.
  • Review of Scientific Instruments, Vol. 87, Issue 2
  • DOI: 10.1063/1.4941047

Works referencing / citing this record:

Outlier classification using autoencoders: Application for fluctuation driven flows in fusion plasmas
journal, January 2019

  • Kube, R.; Bianchi, F. M.; Brunner, D.
  • Review of Scientific Instruments, Vol. 90, Issue 1
  • DOI: 10.1063/1.5049519

Edge transport and mode structure of a QCM-like fluctuation driven by the Shoelace antenna
journal, March 2018