High sensitivity far infrared laser diagnostics for the C-2U advanced beam-driven field-reversed configuration plasmas

August 2016 | B. H. Deng | Review of Scientific Instruments | Paper

A high sensitivity multi-channel far infrared laser diagnostics with switchable interferometry and polarimetry operation modes for the advanced neutral beam-driven C-2U field-reversed configuration (FRC) plasmas is described. The interferometer achieved superior resolution of 1 ⇥ 1016 m 2 at >1.5 MHz bandwidth, illustrated by measurement of small amplitude high frequency fluctuations.

Jet outflow and open field line measurements on the C-2U advanced beam-driven field-reversed configuration plasma experiment

August 2016 | D. Sheftman | Review of Scientific Instruments | Paper

Knowledge and control of the axial outflow of plasma particles and energy along open-magnetic-field lines are of crucial importance to the stability and longevity of the advanced beam-driven field- reversed configuration plasma. An overview of the diagnostic methods used to perform measurements on the open field line plasma on C-2U is presented, including passive Doppler impurity spectroscopy, microwave interferometry, and triple Langmuir probe measurements.

Hanle effect as a magnetic diagnostics for field-reversed configuration plasmas

August 2016 | D. K. Gupta | Review of Scientific Instruments | Paper

Hanle effect is presented as a low magnetic-field diagnostic for field-reversed configuration (FRC) plasmas. The non-perturbative technique is capable of measuring not only magnetic-field pro- file and direction but also field-null position and its shape.

End loss analyzer system for measurements of plasma flux at the C-2U divertor electrode

August 2016 | M. E. Griswold | Review of Scientific Instruments | Paper

An end loss analyzer system consisting of electrostatic, gridded retarding-potential analyzers and pyroelectric crystal bolometers was developed to characterize the plasma loss along open field lines to the divertors of C-2U. The system measures the current and energy distribution of escaping ions as well as the total power flux to enable calculation of the energy lost per escaping electron/ion pair.

First fast-ion D-alpha (FIDA) measurements and simulations on C-2U

August 2016 | N. G. Bolte | Review of Scientific Instruments | Paper

The first measurements of fast-ion D-alpha (FIDA) radiation have been acquired on C-2U, Tri Alpha Energy’s advanced, beam-driven field-reversed configuration (FRC). These measurements are also forward modeled by FIDASIM. This is the first measurement and simulation of FIDA carried out on an FRC topology.

Absolute calibration of neutron detectors on the C-2U advanced beam-driven FRC

August 2016 | R. M. Magee | Review of Scientific Instruments | Paper

In the C-2U fusion energy experiment, high power neutral beam injection creates a large fast ion population that sustains a field-reversed configuration (FRC) plasma. The diagnosis of the fast ion pressure in these high-performance plasmas is therefore critical, and the measurement of the flux of neutrons from the deuterium-deuterium (D-D) fusion reaction is well suited to the task.

Fast imaging diagnostics on the C-2U advanced beam-driven field-reversed configuration device

August 2016 | E. M. Granstedt | Review of Scientific Instruments | Paper

The C-2U device employed neutral beam injection, end-biasing, and various particle fueling tech- niques to sustain a Field-Reversed Configuration (FRC) plasma. As part of the diagnostic suite, two fast imaging instruments with radial and nearly axial plasma views were developed using a common camera platform.

Dual wavelength imaging of a scrape-off layer in an advanced beam-driven field-reversed configuration

August 2016 | D. Osin | Review of Scientific Instruments | Paper

A dual wavelength imaging system has been developed and installed on C-2U to capture 2D images of a He jet in the Scrape-O↵ Layer (SOL) of an advanced beam-driven Field-Reversed Configuration (FRC) plasma. The system was designed to optically split two identical images and pass them through 1 nm FWHM filters.

Enhanced magnetic field probe array for improved excluded flux calculations on the C-2U advanced beam-driven field-reversed configuration plasma experiment

August 2016 | T. Roche | Review of Scientific Instruments | Paper

External flux conserving coils were installed onto the exterior of the C-2U confinement vessel to increase the flux confinement time of the system. The 0.5 in. stainless steel vessel wall has a skin time of ⇠5 ms. The addition of the external copper coils e↵ectively increases this time to ⇠7 ms.