Production of dense plasmas in a hypocycloidal pinch apparatus

A new type of high‐power pinch apparatus consisting of disk electrodes was developed and diagnostic measurements to study its mechanism of dense plasma production have been made. The collapse fronts of the current sheets are well organized and dense plasma foci are produced on the axis with radial stability in excess of 5 μsec. A plasma density greater than 1018 cm−3 is determined with Stark broadening and CO2 laser absorption. Essentially complete absorption of a high‐energy CO2 laser beam has been observed. A plasma temperature of approximately 1 keV is measured with differential transmission of soft x rays through thin foils. The advantages of this apparatus over the coaxial plasma focus are improvements in (1) plasma volume, (2) stability, (3) containment time, (4) access to additional heating by laser or electron beams, and (5) the possibility of scaling up to a multiple array for high‐power operation.