Long Pulse Operation of the Centrifugal Mirror Fusion Experiment (CMFX)*

The goal of CMFX is to investigate the stability and scalability of centrifugally confined plasmas for fusion energy production. An applied voltage across the magnetic field yields an azimuthal E x B drift with supersonic speeds that creates velocity shear that stabilizes and heats the plasma.  A pair of superconducting magnets are used to produce 3 T mirror fields and 0.375 T at midplane. The cylindrical chamber with a length of 6.7 m and diameter of almost 0.8 m contains a high-voltage center electrode, tungsten-coated circular grounding limiters, and bucket-shaped insulators to allow for applied voltages of up to 100 kV. A hydrogen gas-puff system allows for discharges exceeding 200 ms with peak voltages of 20 kV and densities of order 10¹⁸-10¹⁹ m^-3 with momentum confinement times measured at 20 – 30 ms and higher. Ion Doppler spectroscopy, interferometric density diagnostics, and neutron detectors are now operational. Plans for x-ray diagnostics, Thomson scattering, and preliminary data from deuterium discharges at peak voltages of 50 kV are presented.