K-shell X-ray sources at the Z Accelerator

• Published in: High energy density physics 2010-06, Vol.6 (2), p.143-152
• Main Authors: Coverdale, C.A., Jones, B., Ampleford, D.J., Chittenden, J., Jennings, C., Thornhill, J.W., Apruzese, J.P., Clark, R.W., Whitney, K.G., Dasgupta, A., Davis, J., Guiliani, J., LePell, P.D., Deeney, C., Sinars, D.B., Cuneo, M.E.
• Format: Article
• Language: English
• Subjects: K-shell X-rays; Z Accelerator
• ISSN: 1574-1818; 1878-0563
• DOI: 10.1016/j.hedp.2010.01.006

The Z Accelerator has been used for many years as a research facility for high energy density plasmas, with applications ranging from astrophysics to inertial confinement fusion. The available current at the Z Accelerator (>15 MA) has also allowed for experiments over a wide range of K-shell X-ray sources, including Al (∼1.6 keV), Ar (∼3.1 keV), Ti (∼4.8 keV), stainless steel (SS, ∼6.7 keV), and Cu (∼8.4 keV). The K-shell sources provide excellent opportunities for studying the details of a z-pinch through radiated output in various photon energy regimes, imaging, and spectroscopy. Variations in initial load configurations illustrate the difficulty in achieving appropriate plasma conditions for K-shell emissions, particularly for stainless steel and Cu. The requirement for large diameter loads (>40 mm) enhances the growth of the magnetic Rayleigh–Taylor instability during the implosion; evidence of this instability is presented in stagnated pinch data. Data from a variety of K-shell sources and load configurations are presented and discussed to illustrate the details of the imploding and stagnated z pinches. The application of existing and modified scaling theories to the K-shell data is also described, as are multi-dimensional calculations that can be directly compared to the experimental observations. The recent refurbishment of the Z Accelerator will ultimately increase the coupled energy available to a load, with an anticipated peak current of ∼26 MA into a wire array. The current waveforms measured to date are presented, along with a brief discussion of the current status of K-shell work at the Z Accelerator.