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Title: First Argon Gas Puff Experiments With 500 ns Implosion Time On Sphinx Driver

Journal Article · · AIP Conference Proceedings
DOI:https://doi.org/10.1063/1.3079740· OSTI ID:21255350
; ; ; ; ; ; ; ; ; ; ; ;  [1];  [2];  [3]
  1. Centres d'Etudes de Gramat, BP 80200, 46500 Gramat (France)
  2. Consultant, Philomath, OR (United States)
  3. Alameda Applied Sciences Corporation, San Leandro, CA 94577 (United States)

Experiments have been performed at the SPHINX driver to study potential of an Argon Gas Puff load designed by AASC. We present here the gas Puff hardware and results of the last shot series.The Argon Gas Puff load used is injected thanks to a 20 cm diameter nozzle. The nozzle has two annuli and a central jet. The pressure and gas type in each of the nozzle plena can be independently adjusted to tailor the initial gaz density distribution. This latter is selected as to obtain an increasing radial density from outer shell towards the pinch axis in order to mitigate the RT instabilities and to increase radiating mass on axis. A flashboard unit produces a high intensity UV source to pre-ionize the Argon gas. Typical dimensions of the load are 200 mm in diameter and 40 mm height. Pressures are adjusted to obtain an implosion time around 550 ns with a peak current of 3.5 MA.With the goal of improving k-shell yield a mass scan of the central jet was performed and implosion time, mainly given by outer and middle plena settings, was kept constant. Tests were also done to reduce the implosion time for two configurations of the central jet. Strong zippering of the radiation production was observed mainly due to the divergence of the central jet over the 40 mm of the load height. Due to that feature k-shell radiation is mainly obtained near cathode. Therefore tests were done to mitigate this effect first by adjusting local pressure of middle and central jet and second by shortening the pinch length.At the end of this series, best shot gave 5 kJ of Ar k-shell yield. PCD detectors showed that k-shell x-ray power was 670 GW with a FWHM of less than 10 ns.

OSTI ID:
21255350
Journal Information:
AIP Conference Proceedings, Vol. 1088, Issue 1; Conference: 7. international conference on dense Z-pinches, Alexandria, VA (United States), 12-21 Aug 2008; Other Information: DOI: 10.1063/1.3079740; (c) 2009 American Institute of Physics; Country of input: International Atomic Energy Agency (IAEA); ISSN 0094-243X
Country of Publication:
United States
Language:
English