Draft:Princeton Beta Experiment - Modification

• Comment: As is stated when the page was created, it is a draft so belongs as one. The page has trivial spelling errors, incorrectly structured references, does not follow WP:MOS and undefined numbers such as the radius units. Please correct all these and submit your draft for review, otherwise you are making work for volunteer editors. Ldm1954 (talk) 12:47, 22 December 2025 (UTC)

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The Princeton Beta Experiment Modification (PBX-M) was a tokamak constructed at the Princeton Plasma Physics Laboratory (PPPL) in Princeton, NJ, USA for research in nuclear fusion power.

The ultimate goal of this and similar experiments is to advance the science and technology for fusion energy which could provide relatively safe and clean energy. PBX-M was a modification of the Princeton Divertor Experiment - Modification (PDX-M), which one of the first tokamaks constructed with a divertor for reducing the edge heat load and particle recycling into the core plasma. PBX-M had a close-fitting conducting shell and various RF systems to study indented plasmas, and various Radio-Frequency (RF) systems in order to study the physics of current and pressure profile control, and ease the access to the second stability regimes. It achieved suppression of turbulent transport, Edge Lcalized Modes (ELMs) and other related enerey loss mechanisms, and Ion Bernstein Wave modification of H-mode discharges. It demonstrated that enhanced L-mode is most likely due to the large aspect ratio (ratio of major and minor plasma radii = 5.5) of PBX-M either on its own or in combmation with the high triangularity associated with indentation. PDX and PDX-M were operated from roughly 1979-1983 and the PBX-M in 1984-1986. PBX-M was disassembled in 2003.

The PDX, PDX-M, PBX, and PBX-M series of experiments occured between the Princeton Large Torus (PLT) and the Tokamak Fusion Test Reactor (TFTR) experiments at PPPL. Both PLT and TFTR plasmas had toroidal shapes with approximately sircular crossections, unlike those of the PBX series. PLT was the first tokamak to achieve core ion temperatures is the range of 10 keV needed for large rates of fusion of the plasmas with isotopes of hydrogen. TFTR was the first tokamak to perform experiments with relatively large rates of fusion of deuterium with tritium ions.