Investigations of Azimuthal Uniformity, Radial Extrapolation, and View-Factor Corrections for Yield Measurements of K-Shell X-Ray Sources at the Z Accelerator

• Published in: IEEE transactions on plasma science Vol. 38; no. 4; pp. 589 - 597
• Main Authors: Coverdale, Christine A, LePell, P David, Deeney, Christopher, Beutler, David E, Jones, Scott C, Chantler, Gary, Greenwoll, J, Chittenden, J P, Bateson, T, Dudley, K J, Cuneo, Michael E
• Format: Journal Article
• Language: English
• Published: New York IEEE 01-04-2010; The Institute of Electrical and Electronics Engineers, Inc. (IEEE)
• Subjects: Ablation; Acceleration; Accelerators; Arrays; Assessments; Atoms & subatomic particles; Correlation analysis; Diagnostic systems; Extrapolation; K-shell radiation; Measurement; Optical pulses; Optical recording; Phase measurement; Physics; Plasma; Plasma (physics); Plasma measurements; plasma pinch; Position (location); Power measurement; Pulse measurements; Stainless steel; X-ray imaging; X-ray measurements; X-rays
• ISSN: 0093-3813; 1939-9375
• DOI: 10.1109/TPS.2009.2038782

Z -pinch experiments at pulsed-power facilities generally field a wide range of diagnostics, designed to make measurements and study the relevant physics during all phases of the Z -pinch. Optical and X-ray images are collected to study ablation, implosion, and the stagnated pinch; yield and power measurements are made at various photon energies; and time-integrated and time-resolved spectroscopies are recorded to infer plasma conditions before, during, and after stagnation. Typically, diagnostics fielded are dispersed azimuthally around the Z -pinch and at varying distances relative to the Z -pinch. The data are then analyzed and interpreted as a single entity to provide detailed information about a particular process or physics effect. Correlation of the results of the individual diagnostics in this fashion assumes that each diagnostic would measure the same result regardless of its azimuthal or radial location. Assessments of diagnostics to measure K-shell yield at the Z accelerator, which are fielded at varying azimuthal locations and radial distances, are presented. These measurements illustrate that the K-shell emission is azimuthally uniform for titanium, stainless-steel, and copper wire arrays and that the standard correction for radial distance is valid. The importance of view-factor corrections is also discussed.