I assume Eric & the team’s paper will be in the next issue. In the mean time I noticed a few DPF related papers in the January issue
S. Lee et al., “Characterizing Plasma Focus Devices—Role of the Static Inductance—Instability Phase Fitted by Anomalous Resistances,” Journal of Fusion Energy (12, 2010), http://www.springerlink.com/content/b7k152278n905703/.
Morteza Habibi, “Study of Shock Wave and Magnetic Pressure Effects on the Rail Gap Switch Surface Used at the APF Plasma Focus Device,” Journal of Fusion Energy (12, 2010), http://www.springerlink.com/content/fq2u837347720222/.
G. R. Etaati et al., “Angular Distribution of Argon Ions and X-Ray Emissions in the Apf Plasma Focus Device,” Journal of Fusion Energy (11, 2010), http://www.springerlink.com/content/01n65674tg1187k6/.
Lee’s paper is probably the more important of the three. It investigates differences in the current profile between devices with different inductances. Showing the existing Lee model still fits well for low inductance devices but higher inductance devices have an extended dip in the radial phase of the current profile. The extended dip is attributed to a high anomalous resistance:
It is generally accepted [27] that after the regular dynamic phases ending in the formation of the plasma focus pinch, at the end of the pinch the system becomes unstable, develops a high ‘anomalous’ resistivity and breaks up. The overall processes to start this instability takes an exceedingly short time, the experimental observations indicate that the breakup time is far shorter than the ‘regular’ radial phases. This is evident for example in the streak photograph of Fig. 1 which shows that the break up time is less than the duration of the pinch which is measured as 30 ns after a duration of some 80 ns for the radial inward shock and reflected shock phases. There appears to be large number of competing instability processes [27], among which are some with exceedingly short time scales. Hence it appears reasonable to assume that the speed at which the plasma can convert the remnant inductive energy into anomalously resistive energy is ultimately limited by the time scales of the gross electrical components which have to supply the energy for the break-up processes.
It would be interesting to compare FoFu-1 with the others devices.
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