This recent report from Focus Fusion continues to show great
progress. Here they have learned how to
manage the size of the plasmoid itself which will be critical in order to work
with increased densities. It is always
important to find some way to vary the parameters.
I was unable to attach the pictures from the report so it will
be necessary to go to the Lawrenceville site itself to see them. What is different is the introduction of a
coil around the plasmoid.
This is all great progress and this continues to be the
ultimate fusion project able to power starships and everything else with direct
power in the form of electron flow.
December
28, 2011 2
At
right, the AFC is shown in a diagram from LPP’s 2009 US patent; undergoing maintenance
within the detached vacuum chamber by LPP’s researcher Aaron Blake (left).
Lower right –chief scientist Eric Lerner stands under the FF-1 vacuum chamber.
But how can one reliably control a
tornado with a butterfly? First, you need a system that magnifies the effect of
the butterfly’s wings. In FF-1, the magnetic coil—our butterfly—wrapped around
the inside of the vacuum chamber, produces a small vertical magnetic field.
This magnetic field pushes the main current of the device, moving inwards from
the outer electrode, very slightly to the side – perpendicularly, creating a
slight circular motion of the current. This circular motion of the mighty main
electric current in the same direction as the coil’s current increases
the vertical magnetic field. This stronger field then pushes the current ever
more strongly to the side, leading to exponential growth of the vertical field
and the circular current as depicted on Figure 2. This is the magnifying
instability process, similar to the way a tiny swirl in the still water of a
sink produces a fast-spinning vortex when the plug is pulled. It is also
closely related to the non-magnetic process by which meteorological tornadoes
form.
Left:
the copper electrodes mounted onto the FF-1 before the vacuum chamber is added.
The outer 16 rods are the cathodes and the thick inner anode is in the center.
These are the FF-1’s “main electrodes” where main electric currents converge
toward the hole in the anode. 3
Figure
2. As the main current (white) in FF-1 flows inward to the central electrode
(anode), the magnetic field generated by the AFC (not shown here) pushes the
current in a circular direction (yellow arrows), creating a stronger field and
more push, allowing a tiny current to control a huge one.
To control the process, however, you need
to get rid of all but one of the butterflies in the system. This is not
practical for weather control, but is possible in a small vacuum chamber. LPP
researchers have been working hard since August to reduce ―accidental
butterflies by carefully eliminating any sources of random asymmetry that could
set in motion unwanted circular currents. For example, FF-1’s electrodes are
now centered on their shared axis to an accuracy of a thousandth of an inch.
The aim of all this effort is to add more
spin—angular momentum—to the magnetic vortex that compresses the gas down to
form the tiny plasmoid, the dense ball of plasma (electrically conducting gas)
that heats up to produce fusion reactions. (Click for
animation). This idea was first proposed in 2005
by LPP research team member Aaron Blake, and is protected by LPP’s patents in
the US and Australia . With
more spin, the plasmoid can grow bigger, engulfing more plasma and thus
producing more reactions.
However, too much spin will prevent full
compression, so the amount of spin added has to be carefully controlled.
The December 21st result dramatically
shows this control. As the team varied the current in the AFC between zero
(turned off) and 4.5 amps, the high-energy x-rays produced by the plasmoid
changed by over a factor of ten (Figure 3), peaking when the AFC was at a
current of 4.0 amps. The x-rays were measured with a Near Time-of-Flight
instrument, referred to as NTF, which was shielded by 6 mm thick copper filter.
This filter allowed only highly energetic, penetrating x-rays that were
generated by electrons hotter than 100 keV (kiloelectron-Volts, equivalent to
1.1 billion degrees C) to pass through to the NTF, and absorbed less energetic
ones. 4
Figure
3. X-ray output peaks ten-fold in a narrow range of AFC current, showing the
coil’s effectiveness (with error bars).
The data shows that for the narrow range
of AFC from 3.5-4 amps, the plasma is being heated much hotter than for other
settings. Most significantly, the difference in x-ray yield between the average
of the shots at 4 amps and those at zero amps is 15 times greater than the
random variation of yield between the two shots at 4 amps. This allows great
confidence that the effect observed is real, even though only two shots were
taken at each setting in this particular series of tests.
Fusion reactions were also enhanced by
the AFC (Figure 4), although by a factor of 2, not 10. The difference in fusion
yield between the 4-amp and zero-amp settings is still four times as much as
the variation in yield between the two shots at 4 amps, indicating a
significant effect. The greater enhancement of x-rays from the electrons shows
that the electrons were both hotter and the plasmoid was larger, while the
fusion reactions were only increased by the size of the plasmoid, as predicted
by LPP’s theory.
The ability to control the spin of
FoFu-1’s magnetic tornado will be crucial in future experiments, when the
density of the gas is increased to generate far higher fusion yields, and more
spin is required for the denser, slower-moving plasma. LPP’s team then expects
to see even more dramatic results from our magnetic butterfly. 5
Figure
4. Fusion yield doubles in the same narrow range of AFC current, 3.5-4 amperes.
New data archive reveals 4
billion-degree electrons
This December, LPP compiled a data
archive covering the first two years of operation of FF-1, from October 2009 to
October 2011. Preliminary analysis of this data has revealed that at least for
a 30-shot series in September-October 2011, electrons were being consistently
heated to above 400 keV (4 billion degrees C), more than twice as hot as the
ions are heated in our hottest shots. (FLASHBACK: Find discussions of ion
energy earlier in 2011 here). X-rays from such super-hot plasma can be used for
LPP’s spin off technology, X-Scan, for non-destructive inspection.
Earlier in the fall of 2011, we had
performed experiments to measure the spectrum of the x-rays. We know that the
more energetic the x-rays we have, the hotter the electrons that must have
produced them. On Sept 27-Oct 5, we had placed an additional filter in front of
the NTF, so it had 6 mm of total copper thickness, while the FTF, Far Time
of-Flight, continued to have the 3 mm thick filter. The copper filter acts on
the x-rays the way a colored glass filter acts on light, blocking less
energetic x-rays and allowing more energetic ones to pass. Just as a glass
filter that blocked red light and allowed blue to pass would show a brightening
as a metal rod was heated from red-hot to white-hot, the 6mm copper filter
allows us to measure how ―hot‖ (that is, energetic) the x-rays are. We can do
this by comparing the amount of x-rays that pass through the 6 mm filter with
those that only pass the 3 mm one. Now that we have the archive and the
calibration curve, we can go back and compare these 30 shots taken when the NTF
and FTF had different filters with those taken when both devices had the same
filter. 6
We found that no significant difference in the ratio of the NTF to FTF
signals occurred because of the filter. The x-rays were acting as if the 3 mm
copper was transparent. This could only be the case if the x-rays were produced
by electrons that had an average energy of at least 400 keV. We are eager to
analyze more shots for the electron temperature, which is crucial for heating
the ions and thus overall fusion yield. Thanks to LPP’s IT Consultant, Ivana
Karamitsos, for archiving, software tweaks, and data analysis collaboration!
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