title: An ultrafast reciprocating probe.
abstract: For tokamak plasma diagnostics, an ultrafast reciprocating probe system driven by magnetic field coils, achieving a maximum velocity of 21 m/s, is introduced. The probes are attached with a driving hoop made of carbon steel and accelerated by three acceleration coils in series, then decelerated by two deceleration coils and buffer springs and return slowly. The coils with a current of about 1 kA generate a magnetic field of about 1 T. This probe system has been tested on the SUNIST (Sino-UNIted Spherical Tokamak) spherical tokamak. Radial profiles of the floating potential and other plasma parameters measured by this probe system are given.
authors.affiliation: Department of Engineering Physics, Tsinghua University, Beijing 100084, China.
authors.forename: Wenbin
authors.initials: W
authors.lastname: Liu
authors.affiliation: Department of Engineering Physics, Tsinghua University, Beijing 100084, China.
authors.forename: Yi
authors.initials: Y
authors.lastname: Tan
authors.affiliation: Department of Engineering Physics, Tsinghua University, Beijing 100084, China.
authors.forename: Wenhao
authors.initials: W
authors.lastname: Wang
authors.affiliation: Department of Engineering Physics, Tsinghua University, Beijing 100084, China.
authors.forename: Zhe
authors.initials: Z
authors.lastname: Gao