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:
-
- 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}
}
Web of Science
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