Author: Publisher:
ISBN:
Category :
Languages : en
Pages : 19
Book Description
Spectroscopic Measurements of Recent Aluminum Wire Array Z-Pinch Implosions on the Z-Accelerator
Author: Variation of High-power Aluminum-wire Array Z-pinch Dynamics with Wire Number, Array Radius, and Load Mass
Author: Publisher:
ISBN:
Category :
Languages : en
Pages : 18
Book Description
A systematic study of annular aluminum-wire z-pinches on the Saturn accelerator shows that the quality of the implosion, including the radiated power, increases with wire number. Radiation magnetohydrodynamic (RMEC) xy simulations suggest that the implosion transitions from that of individual wire plasmas to that of a continuous plasma shell when the interwire spacing is reduced below (approximately) 1.4 mm. In the plasma-shell regime, the experimental implosions exhibit 1D- and 2D-code characteristics as evidenced by the presence of a strong first and a weak second radiation pulse that correlates with a strong and weak radial convergence. In this regime, many of the radiation and plasma characteristics are in agreement with those simulated by 2D-RMHC rz simulations. Moreover, measured changes in the radiation pulse width with variations in array mass and radius are consistent with the simulations and are explained by the development of 2D fluid motion in the rz plane. Associated variations in the K-shell yield are qualitatively explained by simple K-shell radiation scaling models.
Variation of High-power Aluminum-wire Array Z-pinch Dynamics with Wire Number, Load Mass, and Array Radius
Author: Publisher:
ISBN:
Category :
Languages : en
Pages : 14
Book Description
A systematic study of annular aluminum-wire z-pinches on the Saturn accelerator shows that the quality of the implosion, (as measured by the radial convergence, the radiated energy, pulse width, and power), increases with wire number. Radiation magnetohydrodynamic (RMHC) xy simulations suggest that the implosion transitions from that of individual wire plasmas to that of a continuous plasma shell when the interwire spacing is reduced below (approximately) 1.4 mm. In this plasma-shell regime, many of the global radiation and plasma characteristics are in agreement with those simulated by 2D-RMHC rz simulations. In this regime, measured changes in the radiation pulse width with variations in load mass and array radius are consistent with the simulations and are explained by the development of 2D fluid motion in the rz plane. Associated variations in the K-shell yield are qualitatively explained by simple radiation-scaling models.
The Physics of Long-Pulse Wire Array Z-Pinch Implosions
Author: Publisher:
ISBN:
Category :
Languages : en
Pages : 34
Book Description
Recent improvements in z-pinch wire array load design at Sandia National Laboratories have led to a substantial increase in pinch performance as measured by radiated powers of up to 280 TW in 4 ns and 1.8 MJ of total radiated energy. Next generation, higher current machines will allow for larger mass arrays and comparable or higher velocity implosions to be reached, possibly extending these result.dis the current is pushed above 20 MA, conventional machine design based on a 100 ns implosion time results in higher voltages, hence higher cost and power flow risk. Another approach, which shifts the risk to the load configuration, is to increase the implosion time to minimize the voltage. This approach is being investigated in a series of experimental campaigns on the Saturn and Z machines. In this paper, both experimental and two dimensional computational modeling of the fist long implosion Z experiments will be presented. The experimental data shows broader pulses, lower powers, and larger pinch diameters compared to the corresponding short pulse data. By employing a nested array configuration, the pinch diameter was reduced by 50% with a corresponding increase in power of> 30%. Numerical simulations suggest load velocity is the dominating mechanism behind these results.
Dense Z-Pinches
Author: Jeremy ChittendenPublisher: AIP Conference Proceedings / P
ISBN:
Category : Science
Languages : en
Pages : 400
Book Description
This proceedings volume summarizes the state-of-the-art in Z-pinch research pertaining to applications in inertial confinement fusion, x-ray radiation sources and high energy density plasma physics. Topics include: wire array Z-pinches, single wires and fibers, X-pinches, gas-puffs, plasma focus, capillary discharges and soft X-ray lasers, pulsed power drivers, diagnostic techniques and spectroscopy, as well as theoretical concepts.
Streaked Visible-light Spectroscopy Measurements of Aluminum Wire-array Z-pinches on COBRA.
Author: Energy Research Abstracts
Author: Dense Z-Pinches Fourth International Conference
Author: Nino R. PereiraPublisher: American Institute of Physics
ISBN:
Category : Science
Languages : en
Pages : 662
Book Description
The Proceedings of this Fourth International Conference brought together 129 delegates from 13 countries, with the largest contingents from the US, Russia, the UK, and France. The results of theri rewsearch represent a huge increase in our knowledge of the z-pinch, thanks to new and more comprehensive diagnostics, better computer models, and even more powerful pulse generators. The most prominent example of the latter is the PBFA-Z machine at Sandia National Laboratories, whose record-shattering radiation output is being studied at Sandia and at collaborating laboratories elsewhere.
Numerical Simulations of Annular Wire-array Z-pinches in (x, Y), (r, [theta], and (r, Z) Geometries
![Numerical Simulations of Annular Wire-array Z-pinches in (x, Y), (r, [theta], and (r, Z) Geometries PDF](https://books.google.com/books/content/images/frontcover/jIZjnQAACAAJ?fife=w80-h100)
Author: Publisher:
ISBN:
Category :
Languages : en
Pages : 25
Book Description
The Total Immersion PIC (TIP) code has been used in several two-dimensional geometries to understand better the measured dynamics of annular, aluminum wire-array z-pinches. The areas investigated include the formation of the plasma sheath from current-induced individual wire explosions, the effects of wire number and symmetry on the implosion dynamics, and the dependence of the Rayleigh-Taylor instability growth on initial sheath thickness. A qualitative change in the dynamics with increasing wire number was observed, corresponding to a transition between a z-pinch composed of non-merging, self-pinching individual wires, and one characterized by the rapid formation and subsequent implosion of a continuous plasma sheath. A sharp increase in radiated power with increasing wire number has been observed experimentally near this calculated transition. Although two-dimensional codes have correctly simulated observed power pulse durations, there are indications that three dimensional effects are important in understanding the actual mechanism by which these pulse lengths are produced.
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