The Gabriel Device, possible COP=8

[AmericanMan31]

I think people will find this excerpt pertaining similar values/effects from the Gabriel Device and "interesting" in the least:

...."the split-ring resonators (SRRs) are the most frequently used elements
for achieving effective negative permeability , excited from the time-varying magnetic
field (H-field) vertically to the SRRs plane.
In addition to the excitation from the H-field, under the electric excitation (Efield)
the SRR structures demonstrate multiple-mode  resonances, which are
classified in two groups of eigenfrequencies for electric and magnetic resonances with respect
to the polarization of the illuminating E-field . Specifically, the pure electric responses
are excited once the external E-field is polarized perpendicular to the gap side of SRRs and
can be manifested as even order modes. On the other hand, the odd order
modes all contribute to the magnetic responses that are excited by the polarization
of E-field along the gap side of SRRs.  The fundamental mode of SRRs can be also
regarded as the collective responses from individual LC resonators, in which the gap and the
metallic ring of SRR units represent equivalent capacitance (C) and inductance (L),
respectively . Probably once the spacing between neighboring metallic elements is
not far enough, the interaction among them will unambiguously influence the resonant
properties and the impact of coupling effect can no longer be neglected. In particular, by
breaking the geometrical symmetry of the coupled planar metamaterials, the exceptional
resonance with a very high quality factor can be used. Such a method provides the
additional freedom to manipulate the electromagnetic properties beyond the original resonant
responses of metamaterials.
As a consequence, in this study we introduce an asymmetrically coupled resonance
(ACR), from two different SRR structures in a unit cell whose resonant frequencies are
overlapped but their quality factors are manipulated at the respective small and great values.
By comparing the asymmetrically coupled SRRs from the symmetrically coupled ones, it is
evident to observe an additional transmittance peak with an enhanced quality factor rather
than the original transmittance dip with a low quality factor. Such sharp induced transparency
by the ACR effect originates from strong coupling between a narrow subradiant mode and a
broad superradiant mode in SRR structures, and is significantly modulated by the spacing of
two SRR constituents. Finally, based on various SRR structures including single SRRs,
symmetric SRR pairs and asymmetric SRR pairs, the refractive-index sensitivity and
corresponding sensing performance are further evaluated.
2. Design of SRR units
Referring to the model of standing-wave plasmonic resonances, the multi-mode resonant
frequencies of an SRR element can be quantitatively evaluated by its total length . Such partially
overlapped resonant frequency regions allow us to clarify the coupling effect from two
distinct plasmonic resonances as discussed in next section.
The spectral positions of these two SRR elements are similar, but their quality factors (Qfactors)
are much differentâ€" 13.6 for the SRRn and 3.3 for the SRRw.  Two SRR structures respond similarly to
introduce circulating currents, in which the anti-parallel currents in both side arms cancel each
other giving rise to nearly zero dipole moment. Therefore, the net dipole moments excited
from the external E-field are mainly contributed from the bottom arm of SRRs, leading a
longer bottom arm in the SRRw to a broader bandwidth (defined as FWHM) of resonance due
to the fact that the radiation damping increases with the particle size. In contrast, the
SRRn with a shorter bottom arm contributes to a less radiation damping, resulting in a smaller
value of FWHM,   ...."Induced transparency caused by the suppressed currents due to the destructive
interference between two radiative modes
To interpret the induced transparency from ACR response, the distribution of induced currents
in the asymmetrically integrated SRRs with four different spacings (d) is plotted as shown in
. First, while the spacing, the coupling effect from the SRRn modulates
the resonant condition in the SRRw most and indeed, the net excitation of oscillating currents
within the SRRw displays the weakest one among four cases due to the destructive
interference between resonantly interacting eigenmodes, leading the suppressed net currents to
greater transparency . To Be specific, the oscillating charges in the SRRw are excited through
two pathways: one undergoes the direct resonance in the SRRw by the external E-field, giving
rise to the induced currents in a counterclockwise direction, the other responds to the
clockwise induced currents caused by the coupling in the SRRn, and both pathways introduce
anti-parallel oscillating charges in the SRRw and in turn suppress the net excitation of induced
currents."... 17 August 2009 / Vol. 17, No. 17 / OPTICS EXPRESS 15380

[JouleSeeker]

  I realize there's a lot of interest right now in the Muller generator.  But I hope that the Gabriel device will not be forgotten or neglected!

[casman1969]

Nanoperm core is out of the question for me but I've been looking into similar permeability products I can get in the states. Both are in tape form for easy forming... Metglass and Finemet. Have feelers out for sourcing these products but if any are aware of suppliers, please post.
Finemet appears a rather interesting substitutes.

[taomaster]

The Magnaperm cores do have high permeability according to their specs ... over 70,000 U. The biggest limitation that I can see is that the largest of them is barely over an inch OD, so the device would be rather small.

I've tried attaching the PDF link of their tech specs directly from the web, so I hope it shows up here OK. (If it doesn't, I'll get it up here in the next post).

[casman1969]

Got the specs for both and both are suitable candidates. The only problem is finding suppliers willing to sell. I did find the Magnoperm tape on E-Bay but would prefer to deal directly with the mfg. Sometimes they even give you free samples for your research...
Hey, dreaming is allowed isn't it?