Basic considerations for scaling <i>Z</i>-pinch x-ray emission with atomic number

Whitney, K. G.; Thornhill, J. W.; Apruzese, J. P.; Davis, J.

doi:10.1063/1.345642

Cited by 114 publications

(47 citation statements)

References 16 publications

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“…9D antl 9H, the two-level (10) (solid curves) and the 1D WhitneyGiuliani (20) scaling-model (dashed curves) of K-shell yields are in qualitative agreement with those measured. These K-shell models depend only on the kinetic energy delivered to the load, the effective stagnation radius, and participating mass, and ignoire the multi-dimensional dynamics of the implosion and plasma radiation after stagnation.…”

Section: Figure 9 (A)supporting

confidence: 70%

Variation of high-power aluminum-wire array Z-pinch dynamics with wire number, load mass, and array radius

Sanford

Mock

Marder

et al. 1997

The Fourth International Conference on Dense Z-Pinches

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Abstract. 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 -1.4 mm. In this "plasma-shell regime," many of the global radiation and plasma characteristics are in agreement with those simulated by 2D-FWHC 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.

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Section: Figure 9 (A)supporting

confidence: 70%

Variation of high-power aluminum-wire array Z-pinch dynamics with wire number, load mass, and array radius

Sanford

Mock

Marder

et al. 1997

The Fourth International Conference on Dense Z-Pinches

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“…Thermonuclear neutron yield from a Z-pinch plasma scales with current as J4, like the K-shell x-ray yield in an "inefficient regime" of implosion [33], and for the same reason, see Section II.C below. The peak current of the Z accelerator exceeds the Saturn current by about a factor of 2 to 2.4, so the thermal neutron yield scaled up to Z conditions from the results of [32] is (4 to 8) x 1013 .…”

Section: B Thermonuclear Fusion Conditions Produced In Fast Z-pinch mentioning

confidence: 99%

Z-pinch plasma neutron sources

et al. 2007

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Public reporting burden for this collection of information is estimated to average 1 hour per response, including the time for reviewing instructions, searching existing data sources, gathering and maintaining the data needed, and completing and reviewing this collection of information. Send comments regarding this burden estimate or any other aspect of this collection of intormation, including suggestions for reducing this burden to Department ot Defense, Washington Headquarters Services, Directorate for Information 14. ABSTRACT A deuterium gas-puff load imploded by a multi-MA current driver from a large initial diameter could be a powerful source of fusion neutrons, a plasma neutron source. Unlike the beam-target neutrons produced in Z-pinch plasmas in the 1950s and deuterium-fiber experiments in the 1980s, the neutrons generated in deuterium gas-puffs, with current levels achieved in recent experiments on the SNL Z facility, could contain a substantial fraction of thermonuclear origin. For recent deuterium gas-puff shots ont Z, our analytical estimates and I-D and 2-D simulations predict thermal neutron yields -5 x 1013, in fair agreement with the yields measured on Z. It is demonstrated that the hypothesis of a beam-target origin of the observed fusion neutrons implies a very high Z-pinch-driver-to-fast-ions energy transfer efficiency, 5 to 10%, which would make a multi-MA deuterium Z-pinch the most efficient light-ion accelerator. No matter what mechanism is eventually determined to be responsible for generating fusion neutrons in deuterium gas-puff shots on Z, the neutron yield is shown to scale as y~ I_4 where Im is the peak current of the pinch. Theoretical estimates and numerical modeling of deuterium gas-puff implosions demonstrate that the yields of thermonuclear fusion neutrons that can be produced on ZR and the next generation machines are sufficiently high to make Plasma Neutron Sources (PNS) the most powerful, cost-and energy-efficient laboratory sources of 2.5 to 14 MeV fusion neutron, just like Plasma Radiation Sources (PRS) are the most powerful sources of soft and keV x-rays. In particular, the predicted neutron-producing capability of PNS driven by ZR and ZX accelerators, from -6 x 1016 to _ 1 0 18 matches the projected capability of the NIF laser at thermonuclear energy gains of 1 and 20, respectively.

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“…It is also possible that this continued compressional and joule heating does not in fact occur because current, rather than continuing to flow through the gas, is shorted in a region where the anode-cathode gap is narrow and does not contain a significant amount of radiating plasma. This speculation remains to be tested, but it is consistent with a computational approach used by Whitney, et al 13 whereby the current driving the collapsing plasma is ignored following the development of a prescribed radial kinetic energy. Taking into account only the energy in the sharply rising part of the pulse, the energy radiated beyond 1 kV is about 20 kJ in about 200 ns, compared with measured values of 3 to 20 kJ and about 100 ns.…”

Section: 331mentioning

confidence: 72%