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Diagnostic Support Systems

NSTX-U Systems Capable of Supporting Active Diagnostics – January 2015

(black – available for experiments, blue – under active development)


Purpose of system


Used in diagnostic:


Heating Neutral Beam

Provide neutral population to produce beam emission for various diagnostics

D, 90 - 100 keV, ~50cm V x 20cm H, ~ 150mA/cm2 neutrals entering plasma


T. Stevenson - PPPL

Diagnostic Neutral Beam

Provide excited neutral atoms for intensity and polarimetry measurement

H, 40 keV, 1 - 2 cm dia.,  30 mA neutrals entering plasma


Y. Sechrest, F. Levinton – Nova Photonics

Supersonic Gas Injector

Provides low divergence, high pressure gas jet

Laval nozzle, on midplane probe

Thermal atomic beam spectroscopy

V. Soukhanovskii - LLNL

Laser Blow-Off Impurity Injector

Provides low divergence source (pulse) of atomic impurities for transport studies

Midplane location, multi-pulse, multi-slide, 1 J laser outside NTC

Impurity spectroscopy

P. Beiersdorfer, V. Soukhanovskii - LLNL

Gas Puff Manifold

Provides neutral atoms to highlight edge density turbulence

Linear manifold ^ to edge B field, multiple 1 mm dia holes, D, He or Ar.

gas puff imaging

S. Zweben - PPPL

TAE antenna

Excite stable Alfvén waves to measure linear damping

5-turn radial loop antenna, ≤ 1 kW

Fast Mirnov Coil

E. Fredrickson - PPPL