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Title: Measurement of electron density in complex plasmas of the PK-3 plus apparatus on the International Space Station

Journal Article · · Journal of Applied Physics
DOI:https://doi.org/10.1063/1.3606431· OSTI ID:22036650
;  [1];  [2]
  1. Department of Electronics, Kyoto Institute of Technology, Matsugasaki, Sakyo-ku, Kyoto 606-8585 (Japan)
  2. Institute of Space and Astronautical Science, Japan Aerospace Exploration Agency, 2-1-1 Sengen, Tsukuba, Ibaraki 305-8505 (Japan)

Dust particles in discharge are often levitated in a sheath region rather than in bulk plasma under gravitational conditions (on Earth). Gravity compresses dust clouds, and the gravitational force restricts the motion of the dust particles. Microgravity gives the plasmas, including dust particles, so-called complex (dusty) plasmas, where dust particles are embedded in a completely charge-neutral region of the bulk plasma. The dust cloud, as an uncompressed strongly-coupled Coulomb system, corresponds to an atomic model with physical phenomena, e.g., crystallization, phase transition, and so on. Since the phenomena are tightly connected to plasma states expressed by plasma parameters, it is significant to estimate the plasma parameters, such as electron density and temperature. The present work shows the electron density measured by the frequency shift probe in the apparatus for microgravity experiments currently boarding on the International Space Station (PK-3 plus). The frequency shift probe measurement gave electron density in the order of 10{sup 8} cm{sup -3} as a typical value in the apparatus, and demonstrated the detection of electrons in plasmas with dust particles. The spatial distribution profile of the electron density obtained in this measurement presents an aspect for the void formation of dust clouds under microgravity.

OSTI ID:
22036650
Journal Information:
Journal of Applied Physics, Vol. 110, Issue 1; Other Information: (c) 2011 American Institute of Physics; Country of input: International Atomic Energy Agency (IAEA); ISSN 0021-8979
Country of Publication:
United States
Language:
English