The EQ-10 Electrodeless Z-Pinch™ Metrology Source

The EQ-10 is a discharge-produced plasma Z-pinch source operating in xenon, which relies on induction via a transformer core rather than conduction via electrodes to generate the Z-pinch current. In the basic design, the transformer primary circuit consists of two copper plates connected by a conductive tube at the center. The primary current flows radially in on one plate, axially through the central connection, and radially outward through the second plate. The induced secondary currents flow in a plasma through three electrically parallel paths that pierce the primary structure in three places (the plasma return holes), and then combine in the central bore. Figure 4.1 shows this geometry. Sandwiched between the plates are two magnetic cores. The inner core, closely surrounding the central bore, provides the magnetic flux linkage between the primary current path through the copper and the three parallel secondary currents flowing in the plasma, which combine in the bore to generate the magnetic Z-pinch. The second core is near the outer radius of the device and surrounds the three plasma return holes. This core functions as a magnetic switch with a specific volt-second capacity matched to the capacitance and charging system described below. Figure A4.2 shows a crosssection of the structure.