Turbulence Imaging on the TORPEX Device S. H. M

1
Turbulence Imaging on the TORPEX DeviceS. H.
Müller, A. Fasoli, B. Labit, O. Pisaturo, M.
Podestà, F.M. PoliCRPP Swiss Federal Institute
of Technology
Basic confinement mechanism Toroidal magnetic
field with small vertical component
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Turbulence Imaging on the TORPEX DeviceS. H.
Müller, A. Fasoli, B. Labit, O. Pisaturo, M.
Podestà, F.M. PoliCRPP Swiss Federal Institute
of Technology

• However, simplistic model overestimates
  confinement time by factor of three
• Disagreement seems to be of type of global
  multiplicative factor Missing transport
  channel? must show same Bz dependence
• Turbulence? Possible, as Bz plays also key role
  for turbulence (connection length prop. to Bz-1)
• Look at fluctuations as function of Bz (hydrogen
  plasma)

A lot of reproducible, non-trivial variation
ideal prerequisites for further investigations,
in particular comparison with numerical
simulations
3
Turbulence Imaging on the TORPEX DeviceS. H.
Müller, A. Fasoli, B. Labit, O. Pisaturo, M.
Podestà, F.M. PoliCRPP Swiss Federal Institute
of Technology
Diagnostic development for turbulence imaging
HEXTIP

• Goal
• Space and time
• Background and fluctuations
• Ion saturation current and/or floating potential
• Design
• 4 independent rings mountable at different
  toroidal positions
• 86 ring-shaped tips separated by 3.5 cm
• Mounted on TORPEX mobile sector
• Tests and preliminary results