skip to main content
OSTI.GOV title logo U.S. Department of Energy
Office of Scientific and Technical Information

Title: Electrostatic Dust Detection and Removal for ITER

Abstract

We present some recent results on two innovative applications of microelectronics technology to dust inventory measurement and dust removal in ITER. A novel device to detect the settling of dust particles on a remote surface has been developed in the laboratory. A circuit board with a grid of two interlocking conductive traces with 25 μm spacing is biased to 30 – 50 V. Carbon particles landing on the energized grid create a transient short circuit. The current flowing through the short circuit creates a voltage pulse that is recorded by standard nuclear counting electronics and the total number of counts is related to the mass of dust impinging on the grid. The particles typically vaporize in a few seconds restoring the previous voltage standoff. Experience on NSTX however, showed that in a tokamak environment it was still possible for large particles or fibers to remain on the grid causing a long term short circuit. We report on the development of a gas puff system that uses helium to clear such particles. Experiments with varying nozzle designs, backing pressures, puff durations, and exit flow orientations have given an optimal configuration that effectively removes particles from an area up to 25 cm²more » with a single nozzle. In a separate experiment we are developing an advanced circuit grid of three interlocking traces that can generate a miniature electrostatic traveling wave for transporting dust to a suitable exit port. We have fabricated such a 3-pole circuit board with 25 micron insulated traces that operates with voltages up to 200 V. Recent results showed motion of dust particles with the application of only 50 V bias voltage. Such a device could potentially remove dust continuously without dedicated interventions and without loss of machine availability for plasma operations.« less

Authors:
; ; ; ; ;
Publication Date:
Research Org.:
Princeton Plasma Physics Laboratory (PPPL), Princeton, NJ
Sponsoring Org.:
USDOE Office of Science (SC)
OSTI Identifier:
938797
Report Number(s):
PPPL-4351
TRN: US0806132
DOE Contract Number:  
DE-AC02-76CH03073
Resource Type:
Conference
Resource Relation:
Conference: Twenty-Second IAEA Fusion Energy Conference - 50th Anniversary of Controlled Nuclear Fusion Research, 13 - 18 October 2008, Geneva, Switzerland.
Country of Publication:
United States
Language:
English
Subject:
70 PLASMA PHYSICS AND FUSION TECHNOLOGY; CARBON; CONFIGURATION; DETECTION; DUSTS; ELECTRICAL FAULTS; ELECTROSTATICS; FIBERS; HELIUM; IAEA; MICROELECTRONICS; NOZZLES; PLASMA; REMOVAL; THERMONUCLEAR REACTORS; TRANSIENTS; ITER; Dust Diagnostics; Dust Particles

Citation Formats

C.H. Skinner, A. Campos, H. Kugel, J. Leisure, A.L. Roquemore, and S. Wagner. Electrostatic Dust Detection and Removal for ITER. United States: N. p., 2008. Web.
C.H. Skinner, A. Campos, H. Kugel, J. Leisure, A.L. Roquemore, & S. Wagner. Electrostatic Dust Detection and Removal for ITER. United States.
C.H. Skinner, A. Campos, H. Kugel, J. Leisure, A.L. Roquemore, and S. Wagner. Mon . "Electrostatic Dust Detection and Removal for ITER". United States. https://www.osti.gov/servlets/purl/938797.
@article{osti_938797,
title = {Electrostatic Dust Detection and Removal for ITER},
author = {C.H. Skinner and A. Campos and H. Kugel and J. Leisure and A.L. Roquemore and S. Wagner},
abstractNote = {We present some recent results on two innovative applications of microelectronics technology to dust inventory measurement and dust removal in ITER. A novel device to detect the settling of dust particles on a remote surface has been developed in the laboratory. A circuit board with a grid of two interlocking conductive traces with 25 μm spacing is biased to 30 – 50 V. Carbon particles landing on the energized grid create a transient short circuit. The current flowing through the short circuit creates a voltage pulse that is recorded by standard nuclear counting electronics and the total number of counts is related to the mass of dust impinging on the grid. The particles typically vaporize in a few seconds restoring the previous voltage standoff. Experience on NSTX however, showed that in a tokamak environment it was still possible for large particles or fibers to remain on the grid causing a long term short circuit. We report on the development of a gas puff system that uses helium to clear such particles. Experiments with varying nozzle designs, backing pressures, puff durations, and exit flow orientations have given an optimal configuration that effectively removes particles from an area up to 25 cm² with a single nozzle. In a separate experiment we are developing an advanced circuit grid of three interlocking traces that can generate a miniature electrostatic traveling wave for transporting dust to a suitable exit port. We have fabricated such a 3-pole circuit board with 25 micron insulated traces that operates with voltages up to 200 V. Recent results showed motion of dust particles with the application of only 50 V bias voltage. Such a device could potentially remove dust continuously without dedicated interventions and without loss of machine availability for plasma operations.},
doi = {},
journal = {},
number = ,
volume = ,
place = {United States},
year = {2008},
month = {9}
}

Conference:
Other availability
Please see Document Availability for additional information on obtaining the full-text document. Library patrons may search WorldCat to identify libraries that hold this conference proceeding.

Save / Share: