Space and Time Resolved Measurements of Current and Electron Density Profiles Around High Current Z-Pinches

IT IS PROPOSED TO USE A SENSITIVE LASER PROBE BEAM TO MEASURE, VIA BEAM REFRACTION AND FARADAY ROTATION, THE PLASMA DENSITIES AND MAGNETIC FIELDS (HENCE CURRENT PROFILES) AROUND HIGH CURRENT Z-PINCHES. DURING PHASE I, A SIMPLE VERSION OF THE PROPOSED LASER METROLOGY TOOL, USING MANY COMPONENTS ALREADY AVAILABLE AT SRL, WILL BE VALIDATED BY MEASURING THE -0.5 MA CURRENTS (100-300 T MAGNETIC FIELDS) AND 1020 CM-3 ELECTRON DENSITIES AROUND A DENSE PLASMA FOCUS (DPF) Z-PINCH, WHICH IS ALSO ALREADY AVAILABLE AT SRL. ALTHOUGH THIS DPF PINCH OPERATES AT RELATIVELY LOW CURRENT, THE MAGNETIC FIELDS AND ELECTRON DENSITIES ARE WITHIN A FACTOR OF 2-3 OF THOSE EXPECTED IN HIGHER CURRENT SLMULATORS SUCH AS PHOENIX OR DECADE. THE PHASE I VALIDATION TESTS WILL THEREFORE PROVIDE RELIABLE DESIGN CRITERIA FOR A HIGHER POWERED VERSION OF THE LASER METROLOGY TOOL FOR PHASE II. DURING PHASE II, SUCH AN UPGRADED VERSION OF THE LASER TOOL WILL BE BUILT AND TESTED ON HIGH CURRENT Z-PINCH SOURCES SUCH AS PHOENIX OR DECADE.