Langmuir probe diagnostic suite in the C-2 field-reversed configuration

Journal Article · Sat Nov 15 00:00:00 EST 2014 · Review of Scientific Instruments

DOI:https://doi.org/10.1063/1.4890535· OSTI ID:22308612

Armstrong, S.; Knapp, K.; Slepchenkov, M. ^[1]; Sun, X. ^[2]

---

1. Tri Alpha Energy Inc., PO Box 7010, Rancho Santa Margarita, California 92688 (United States)
2. Department of Modern Physics, University of Science and Technology of China, Hefei Anhui 230026 (China)

Several in situ probes have been designed and implemented into the diagnostic array of the C-2 field-reversed configuration (FRC) at Tri Alpha Energy [M. Tuszewski et al. (the TAE Team), Phys. Rev. Lett. 108, 255008 (2012)]. The probes are all variations on the traditional Langmuir probe. They include linear arrays of triple probes, linear arrays of single-tipped swept probes, a multi-faced Gundestrup probe, and an ion-sensitive probe. The probes vary from 5 to 7 mm diameter in size to minimize plasma perturbations. They also have boron nitride outer casings that prevent unwanted electrical breakdown and reduce the introduction of impurities. The probes are mounted on motorized linear-actuators allowing for programmatic scans of the various plasma parameters over the course of several shots. Each probe has a custom set of electronics that allows for measurement of the desired signals. High frequency ( > 5MHz) analog optical-isolators ensure that plasma parameters can be measured at sub-microsecond time scales while providing electrical isolation between machine and data acquisition systems. With these probes time-resolved plasma parameters (temperature, density, spatial potential, flow, and electric field) can be directly/locally measured in the FRC jet and edge/scrape-off layer.

• OSTI ID: 22308612
• Journal Information: Review of Scientific Instruments, Vol. 85, Issue 11; Other Information: (c) 2014 AIP Publishing LLC; Country of input: International Atomic Energy Agency (IAEA); ISSN 0034-6748
• Country of Publication: United States
• Language: English

Related Subjects

71 CLASSICAL AND QUANTUM MECHANICS
GENERAL PHYSICS
46 INSTRUMENTATION RELATED TO NUCLEAR SCIENCE AND TECHNOLOGY
ACTUATORS
BORON NITRIDES
DATA ACQUISITION SYSTEMS
DISTURBANCES
ELECTRIC FIELDS
ELECTRICAL FAULTS
ELECTRON TEMPERATURE
FIELD-REVERSED THETA PINCH DEVICES
ION TEMPERATURE
LANGMUIR PROBE
PLASMA
PLASMA DENSITY
PLASMA IMPURITIES
PLASMA JETS
PLASMA SCRAPE-OFF LAYER
TIME RESOLUTION