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:10.1063/1.4990043

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

Journal Article · Wed Jul 05 00:00:00 EDT 2017 · Review of Scientific Instruments

DOI:https://doi.org/10.1063/1.4990043· OSTI ID:1474327

^[1]; ^[2]; LaBombard, B. ^[2]; Burke, W. ^[2]

Massachusetts Inst. of Technology (MIT), Cambridge, MA (United States). Plasma Science and Fusion Center; Massachusetts Institute of Technology
Massachusetts Inst. of Technology (MIT), Cambridge, MA (United States). Plasma Science and Fusion Center

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.

View Accepted Manuscript (DOE)

Research Organization:: Massachusetts Inst. of Technology (MIT), Cambridge, MA (United States)

Sponsoring Organization:: USDOE Office of Science (SC)

Grant/Contract Number:: FC02-99ER54512

OSTI ID:: 1474327

Alternate ID(s):: OSTI ID: 1367935

Journal Information:: Review of Scientific Instruments, Journal Name: Review of Scientific Instruments Journal Issue: 7 Vol. 88; ISSN 0034-6748

Publisher:: American Institute of Physics (AIP)Copyright Statement

Country of Publication:: United States

Language:: English

References (20)

Electric Probes in Tokamaks: Experience in Tore Supra Gunn, J. P.; Pascal, J. -Y.; Saint-Laurent, F. Contributions to Plasma Physics, Vol. 51, Issue 2-3 https://doi.org/10.1002/ctpp.201000074	journal	March 2011
MDSplus objects—Python implementation Fredian, T.; Stillerman, J.; Manduchi, G. Fusion Engineering and Design, Vol. 85, Issue 3-4 https://doi.org/10.1016/j.fusengdes.2010.04.029	journal	July 2010
Plasma profiles and flows in the high-field side scrape-off layer in Alcator C-Mod Smick, N.; LaBombard, B.; Pitcher, C. S. Journal of Nuclear Materials, Vol. 337-339 https://doi.org/10.1016/j.jnucmat.2004.09.035	journal	March 2005
MDS plus data acquisition system Stillerman, J. A.; Fredian, T. W.; Klare, K. A. Review of Scientific Instruments, Vol. 68, Issue 1 https://doi.org/10.1063/1.1147719	journal	January 1997
A fast moving diagnostic system on the RFX experiment Desideri, D.; Serianni, G.; Antoni, V. Review of Scientific Instruments, Vol. 70, Issue 1 https://doi.org/10.1063/1.1149310	journal	January 1999
Development of a high-speed, reciprocating electrostatic probe system for Hall thruster interrogation Haas, James M.; Gallimore, Alec D.; McFall, Keith Review of Scientific Instruments, Vol. 71, Issue 11 https://doi.org/10.1063/1.1318921	journal	January 2000
Magnetically driven filament probe Schmid, A.; Herrmann, A.; Rohde, V. Review of Scientific Instruments, Vol. 78, Issue 5 https://doi.org/10.1063/1.2735942	journal	May 2007
Mirror Langmuir probe: A technique for real-time measurement of magnetized plasma conditions using a single Langmuir electrode LaBombard, B.; Lyons, L. Review of Scientific Instruments, Vol. 78, Issue 7 https://doi.org/10.1063/1.2754392	journal	July 2007
Wall scanning probe for high-field side plasma measurements on Alcator C-Mod Smick, Noah; LaBombard, Brian Review of Scientific Instruments, Vol. 80, Issue 2 https://doi.org/10.1063/1.3069290	journal	February 2009
Fast scanning probe for the NSTX spherical tokamak Boedo, J. A.; Crocker, N.; Chousal, L. Review of Scientific Instruments, Vol. 80, Issue 12 https://doi.org/10.1063/1.3266065	journal	December 2009
Fast reciprocating probe system on the EAST superconducting tokamak Zhang, W.; Chang, J. F.; Wan, B. N. Review of Scientific Instruments, Vol. 81, Issue 11 https://doi.org/10.1063/1.3499237	journal	November 2010
A magnetically driven reciprocating probe for tokamak scrape-off layer measurements Gunn, J. P.; Pascal, J. -Y. Review of Scientific Instruments, Vol. 82, Issue 12 https://doi.org/10.1063/1.3661128	journal	December 2011
Surface thermocouples for measurement of pulsed heat flux in the divertor of the Alcator C-Mod tokamak Brunner, D.; LaBombard, B. Review of Scientific Instruments, Vol. 83, Issue 3 https://doi.org/10.1063/1.3689770	journal	March 2012
Scanning retarding field analyzer for plasma profile measurements in the boundary of the Alcator C-Mod tokamak Brunner, D.; LaBombard, B.; Ochoukov, R. Review of Scientific Instruments, Vol. 84, Issue 3 https://doi.org/10.1063/1.4793785	journal	March 2013
Feedback system for divertor impurity seeding based on real-time measurements of surface heat flux in the Alcator C-Mod tokamak Brunner, D.; Burke, W.; Kuang, A. Q. Review of Scientific Instruments, Vol. 87, Issue 2 https://doi.org/10.1063/1.4941047	journal	February 2016
An ultrafast reciprocating probe Liu, Wenbin; Tan, Yi; Wang, Wenhao Review of Scientific Instruments, Vol. 87, Issue 11 https://doi.org/10.1063/1.4962060	journal	September 2016
Intermittent transport across the scrape-off layer: latest results from ASDEX Upgrade Kočan, M.; Müller, H. W.; Nold, B. Nuclear Fusion, Vol. 53, Issue 7 https://doi.org/10.1088/0029-5515/53/7/073047	journal	June 2013
The effect of transient temporal pulse shape on surface temperature and tungsten damage Yu, J. H.; De Temmerman, G.; Doerner, R. P. Nuclear Fusion, Vol. 55, Issue 9 https://doi.org/10.1088/0029-5515/55/9/093027	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 Brunner, D.; LaBombard, B.; Churchill, R. M. Plasma Physics and Controlled Fusion, Vol. 55, Issue 9 https://doi.org/10.1088/0741-3335/55/9/095010	journal	July 2013
The Plasma Boundary of Magnetic Fusion Devices Stangeby, Peter C. Plasma Physics and Controlled Fusion, Vol. 43, Issue 2 https://doi.org/10.1887/0750305592	book	January 2000

Cited By (4)

Outlier classification using autoencoders: Application for fluctuation driven flows in fusion plasmas Kube, R.; Bianchi, F. M.; Brunner, D. Review of Scientific Instruments, Vol. 90, Issue 1 https://doi.org/10.1063/1.5049519	journal	January 2019
An experimental assessment of methods used to compute secondary electron emission yield for tungsten and molybdenum electrodes based on exposure to Alcator C-Mod scrape-off layer plasmas McCarthy, W.; LaBombard, B.; Brunner, D. Plasma Physics and Controlled Fusion, Vol. 60, Issue 3 https://doi.org/10.1088/1361-6587/aaa51c	journal	February 2018
Edge transport and mode structure of a QCM-like fluctuation driven by the Shoelace antenna Golfinopoulos, T.; LaBombard, B.; Brunner, D. Nuclear Fusion, Vol. 58, Issue 5 https://doi.org/10.1088/1741-4326/aab2c8	journal	March 2018
Outlier classification using Autoencoders: application for fluctuation driven flows in fusion plasmas Kube, R.; Bianchi, F. M.; Brunner, D. arXiv https://doi.org/10.48550/arxiv.1804.08927	text	January 2018

Similar Records

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

Dataset · Tue Oct 16 00:00:00 EDT 2018 · OSTI ID:1880103

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

Journal Article · Tue Feb 09 23:00:00 EST 2016 · Review of Scientific Instruments · OSTI ID:1897622

Observation of Efficient Lower Hybrid Current Drive at High Density in Diverted Plasmas on the Alcator C-Mod Tokamak

Dataset · Thu Jan 17 23:00:00 EST 2019 · OSTI ID:1881223

Related Subjects

70 PLASMA PHYSICS AND FUSION TECHNOLOGY

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

Citation Formats

References (20)

Cited By (4)

Similar Records

Related Subjects