New paper from Chile. Low pressure D2 plasma produces low neutron emission
Evidence of nuclear fusion neutrons from an extremely small plasma focus device operating at 0.1 Joules
Leopoldo Soto1,2,3,a), Cristián Pavéz1,2,3, José Moreno1,2,3, Luis Altamirano2,4, Luis Huerta2,5, Mario Barbaglia6, Alejandro Clausse6, and Roberto E. Mayer7
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Physics of Plasmas 24, 082703 (2017
ABSTRACT
.We report on D-D fusion neutron emission in a plasma device with an energy input of only 0.1 J, within a range where fusion events have been considered very improbable. The results presented here are the consequence of scaling rules we have derived, thus being the key point to assure the same energy density plasma in smaller devices than in large machines. The Nanofocus (NF)—our device—was designed and constructed at the P4 Lab of the Chilean Nuclear Energy Commission. Two sets of independent measurements, with different instrumentation, were made at two laboratories, in Chile and Argentina. The neutron events observed are 20σ greater than the background. The NF plasma is produced from a pulsed electrical discharge using a submillimetric anode, in a deuterium atmosphere, showing empirically that it is, in fact, possible to heat and compress the plasma. The strong evidence presented here stretches the limits beyond what was expected. A thorough understanding of this could possibly tell us where the theoretical limits actually lie, beyond conjectures. Notwithstanding, a window is thus open for low cost endeavours for basic fusion research. In addition, the development of small, portable, safe nonradioactive neutron sources becomes a feasible issue.
Mizuno-Sensei uses about ~500 Pa.
Los investigadores
"The detectors only gave off neutron signals in deuterium discharges under pressures from 1 to 4 mbar and from 14.5 to 17.5 mbar."
"a device working at a few joules, with 103 to 104 shots at a frequency of 10 to 100 Hz,
will produce a neutron yield of 104 to 106 events per second, .
A deuterium-tritium mixture would boost this by up to 100 times."
"In much smaller devices, the surface/volume ratio seems to be more favorable for plasma heating and compression. "
"We conclude that ...an extremely small plasma device operating at only 0.1–0.2 J, can produce D-D fusion reactions."