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.

Characterization of compact-toroid injection during formation, translation, and field-penetration

July 2016 | T. Matsumoto | Review of Scientific Instruments | Paper

We have developed a compact toroid (CT) injector system for particle refueling of the advanced beam- driven C-2U field-reversed configuration (FRC) plasma. The CT injector is a magnetized coaxial plasma gun (MCPG), and the produced CT must cross the perpendicular magnetic field surrounding the FRC for the refueling of C-2U.

A mass resolved, high resolution neutral particle analyzer for C-2U

July 2016 | Ryan Clary | Review of Scientific Instruments | Paper

C-2U is a high-confinement, advanced beam driven field-reversed configuration plasma experiment which sustains the configuration for >5 ms, in excess of typical MHD and fast particle instability times, as well as fast particle slowing down times.

Innovative high-gain optically pumped far-infrared laser

July 2016 | B. Deng | Applied Optics | Paper

A new optically pumped far-infrared (FIR) laser with separate pump beam reflector and FIR output coupler has been developed. The new design greatly simplifies the tuning of the laser and enables the optimization of the pump beam absorption without affecting the laser alignment.