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Modified 3D-helix-like instability structure for imploding Z-pinch liners that are premagnetized with a uniform axial field

Awe, Thomas J.; Jennings, Christopher A.; McBride, Ryan D.; Cuneo, M.E.; Lamppa, Derek C.; Martin, Matthew; Rovang, Dean C.; Sinars, Daniel S.; Slutz, Stephen A.; Owen, Albert C.; Gomez, Matthew R.; Hansen, Stephanie B.; Harding, Eric H.; Herrmann, Mark H.; Jones, Michael J.; Knapp, Patrick K.; Mckenney, John M.; Peterson, Kyle J.; Robertson, Grafton K.; Rochau, G.A.; Savage, Mark E.; Schmit, Paul S.; Sefkow, Adam B.; Stygar, William A.; Vesey, Roger A.; Yu, Edmund Y.; Tomlinson, Kurt T.; Schroen, Diana G.

Abstract not provided.

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TYPE Presentation YEAR 2014
OSTI

Signatures of hot electrons and fluorescence in Mo Kα emission on Z

Physics of Plasmas

Hansen, Stephanie B.; Ampleford, David A.; Cuneo, M.E.; Ouart, N.; Jones, Brent M.; Jennings, C.A.; Dasgupta, A.; Coverdale, Christine A.; Rochau, G.A.; Dunham, Gregory S.; Giuliani, J.L.; Apruzese, J.P.

Recent experiments on the Z accelerator have produced high-energy (17 keV) inner-shell K-alpha emission from molybdenum wire array z-pinches. Extensive absolute power and spectroscopic diagnostics along with collisional-radiative modeling enable detailed investigation into the roles of thermal, hot electron, and fluorescence processes in the production of high-energy x-rays. We show that changing the dimensions of the arrays can impact the proportion of thermal and non-thermal K-shell x-rays. © 2014 AIP Publishing LLC.

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TYPE Conference YEAR 2014
ScopusOSTI

Modified helix-like instability structure on imploding z-pinch liners that are pre-imposed with a uniform axial magnetic field

Physics of Plasmas

Awe, Thomas J.; Owen, Albert C.; Gomez, Matthew R.; Hansen, Stephanie B.; Herrmann, Mark H.; Jones, Michael J.; Mckenney, John M.; Robertson, Grafton K.; Rochau, G.A.; Savage, Mark E.; Stygar, William A.; Jennings, Christopher A.; McBride, Ryan D.; Lamppa, Derek C.; Martin, Matthew; Rovang, Dean C.; Sinars, Daniel S.; Slutz, Stephen A.; Cuneo, M.E.

Abstract not provided.

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TYPE Journal Article YEAR 2014
OSTIDOI

X-ray power and yield measurements at the refurbished Z machine

Review of Scientific Instruments

Jones, Brent M.; Ampleford, David A.; Cuneo, M.E.; Hohlfelder, Robert J.; Jennings, C.A.; Johnson, Drew J.; Jones, Brent M.; Lopez, M.R.; Macarthur, J.; Mills, Jerry A.; Preston, T.; Rochau, G.A.; Savage, Mark E.; Spencer, D.; Sinars, Daniel S.; Porter, J.L.

Advancements have been made in the diagnostic techniques to measure accurately the total radiated x-ray yield and power from z-pinch implosion experiments at the Z machine with high accuracy. The Z machine is capable of outputting 2 MJ and 330 TW of x-ray yield and power, and accurately measuring these quantities is imperative. We will describe work over the past several years which include the development of new diagnostics, improvements to existing diagnostics, and implementation of automated data analysis routines. A set of experiments on the Z machine were conducted in which the load and machine configuration were held constant. During this shot series, it was observed that the total z-pinch x-ray emission power determined from the two common techniques for inferring the x-ray power, a Kimfol filtered x-ray diode diagnostic and the total power and energy diagnostic, gave 449 TW and 323 TW, respectively. Our analysis shows the latter to be the more accurate interpretation. More broadly, the comparison demonstrates the necessity to consider spectral response and field of view when inferring x-ray powers from z-pinch sources. © 2014 AIP Publishing LLC.

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TYPE Journal Article YEAR 2014
ScopusOSTIDOI

Observations of Modified Three-Dimensional Instability Structure for Imploding z -Pinch Liners that are Premagnetized with an Axial Field

Physical Review Letters

McBride, Ryan D.; Gomez, Matthew R.; Hansen, Stephanie B.; Herrmann, Mark H.; Mckenney, John M.; Robertson, Grafton K.; Rochau, G.A.; Savage, Mark E.; Stygar, William A.; Jennings, Christopher A.; Lamppa, Derek C.; Martin, Matthew; Rovang, Dean C.; Slutz, Stephen A.; Cuneo, M.E.; Owen, Albert C.; Sinars, Daniel S.

Novel experimental data are reported that reveal helical instability formation on imploding z -pinch liners that are premagnetized with an axial field. Such instabilities differ dramatically from the mostly azimuthally symmetric instabilities that form on unmagnetized liners. The helical structure persists at nearly constant pitch as the liner implodes. This is surprising since, at the liner surface, the azimuthal drive field presumably dwarfs the axial field for all but the earliest stages of the experiment. These fundamentally 3D results provide a unique and challenging test for 3D-magnetohydrodynamics simulations.

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TYPE Journal Article YEAR 2013
OSTIDOI
Results 101–125 of 365
Results 101–125 of 365