**3. Areas for specific application of SFCO** *absolute-***position sensors**

Besides the usage of the SFCO technology - based *absolute*-position sensors in seismic predicttion & protection, they might be also effectively applied in: *security systems*; *geophysics & town-planning; micro- & nano-electronics; military science*, *engineering & intelligence;* etc.:

Fig. 9-10. The *SFCO-*sensor based *Early Warning Security System* can secure the runway and specific underwater perimeter with the invisible and totally passive security net, and can detect over the ground and underground, as well as underwater moving intruders.

*in security systems:* The new (**SFCO**) technology *absolute-*position sensor-based ultra-sensitive seismic detectors and vacuum gages may give rise to many markets & applications, and bring to products that can serve both military & civilian applications. Early warning security systems (**EWSS**) are natural applications that can serve to protect State & Federal borders, provide Ports security & control, as well as Civilian applications of perimeter security

the replacement of the normal-metallic coil by the superconductive one. This may improve the tunnel diode oscillator stability by at least 1-2 orders of magnitude [2]. The next improvement relates with the substitution of the tunnel diode by the superconductive *S/I/S* hetero-structure as much more less-powered active element (*compared to tunnel diodes*) for the measuring oscillator of the *SFCO absolute-*position sensor, with a few orders of magnitude less steep of its *I-V* curve's negative differential resistance [16]. This may raise the oscillator stability by another 2-3 orders of a value [2]. Even these two modernizations are enough in order to enhance the stability of the measuring and reference oscillators of such a technique (Fig.3) and hence, to increase the signal-to-noise ratio (*sensitivity*) of the *SFCO* technologybased seismic detectors – by at least 3-4 orders of a value. As follows from the Fig.5, the *absolute-*resolution of such a new sensor drops exponentially when a normal-conducting plate moves away from the coil face. This property of *SFCO* sensors makes easy adjustment of the sensitivity (*resolution*) of such a new position sensor, for various practical usages in future.

**3. Areas for specific application of SFCO** *absolute-***position sensors** 

Besides the usage of the SFCO technology - based *absolute*-position sensors in seismic predicttion & protection, they might be also effectively applied in: *security systems*; *geophysics & town-planning; micro- & nano-electronics; military science*, *engineering & intelligence;* etc.:

 Fig. 9-10. The *SFCO-*sensor based *Early Warning Security System* can secure the runway and specific underwater perimeter with the invisible and totally passive security net, and can detect over the ground and underground, as well as underwater moving intruders.

*in security systems:* The new (**SFCO**) technology *absolute-*position sensor-based ultra-sensitive seismic detectors and vacuum gages may give rise to many markets & applications, and bring to products that can serve both military & civilian applications. Early warning security systems (**EWSS**) are natural applications that can serve to protect State & Federal borders, provide Ports security & control, as well as Civilian applications of perimeter security

Fig. 11. The *SFCO-*sensor based *Early Warning Security System* can secure the ground and underground, as well as specific underwater perimeter with the invisible and totally passive security net, and identify the location of underwater moving intruders.

layer flat coil of about 1mm in diameter [23] – *as an effective needle-type probing instrument with better than* 100nm *predicted lateral resolution*. Such a radically new probe will have considerably *large work-distances* (more than 100m) *between the probe and surface of the object*, which enables a "visual" control of the local area of probing of the object, and, if needed,

*in military science, engineering and Intelligence:* to detect onset and amount of attacking soldiery of enemy arm-forces in the absence of direct visibility, and to reveal and detect lowpowered nuclear weapon tests. Besides, to solve the perimeter or/and zone-security prob-

*In a precision sensor industry:* for creation of non-contact acceleration sensors (*the pickups*) of

application of test perturbations (for example, exposition to laser radiation).

lems for the intelligence group(s), as well as for the special mission unit(s).

a) b)

the *sub*-Angstrom *spatial-*resolution gravity-wave detection.

Fig. 12. Dependence of the *SFCO* technique's *TD* oscillator frequency shift

the lateral position of the *1D* grid-shaped metallic object (**a**) relative to the "*probe-formative*"

*in a basic research:* for high-precision measurements of the Casimir Force and very little friction related with it. Besides, high- and/or low-*T*c superconductive coil-based 3D analogue of such a new, ultra-sensitive *SFCO-*position sensor seems to be very useful also for

A new class super-broadband nano-scale-resolution position sensor appeared quite recently. It can be used, in particular, as an additional sensor in seismographs. It enables to extend the frequency-band (up to "zero"), and enhance the absolute-resolution (*sensitivity*) of the vibrometers and seismographs, available on the market, by 10-100 times, depending on the model of the base product (such as the American KS-1/KS-54000 and FBA-23, the European GS-13 and STS-1/STS-2, and the Russian SM-3 – presented and discussed above *SFCO*sensor was installed just inside the SM-3 seismometer, and compared with its own sensor).

*(*

*F)[kHz]* (**b**) on

*super-*high resolution.

flat coil face.

**4. Conclusion** 

controls such as security of oil pipelines, airports, and private properties. The new technology sensors may also enable detection and recognition of various mobile targets (*walking or crawling man*, *vehicles*, *tanks*, *or other human activities*) approaching any zone (*military camps, state properties, banks, or other critical high priority infrastructures*) or borders without the need of physical line of sight.

Figures 9 through 11 are pictorial depictions of systemic applications to real world security scenarios, showing the flexibility and versatility of this new technology rendering one of the highest quality EWSS for military or civilian applications, covering detection for underground movements, over the ground movements, and underwater movement.

*in geophysics and town-planning:* for gas and oil prospecting, and also to reveal too much weak vibrations and slow bending (*twist*) of the buildings, constructions and bridges, as well as for permanent monitoring of old bridges aging;

*in micro- and nano-electronics:* for creation of *New Generation* microscopes with long-range action "*magnetic-field*" probes.

Our recent research shows [17-18], that flat coil based *TD-*oscillators can be activated also with their internal capacitances (*without an external capacitance C in their resonant circuits –* see **Fig.3**). That is the result of relatively high value of internal capacitances of single-layer flat coils compared to their parasitic capacitances with respect to the surrounding radiotechnical environment. This opens one more exotic area for flat-coil oscillator application. Namely, a "*needle-like*" testing magnetic field of such a flat coil (see **Fig.12a**), used as a pick-up in such a stable *TD*-oscillator, enables a novel method (*new approach*) for surface probing, based on replacement of short-range, solid-state probes of acting microscopes (*such as needles or cantilevers of tunneling* [19-20] *and atomic-force* [21] *microscopes*, *probes of the near-field microscopes*, etc.) by the long-range action non-solid-state ones. Such an unusual probe shows strong dependence of a detected signal on the size of the spatial-gap between the probe and the surface of the object crucial for the probe microscopy (**PM**) [22]. This opens an opportunity for creating of the "*magnetic-field*" probes with a *RF* power applied to the sample lying in the range of 1nW to 5W. The gap between such a "*probe-formative*" flat coil and the object can be larger than 100m [18], compared with the 1nm gap of the acting probe microscopes [22]. In our tests we reached a lateral resolution 1m even for the relatively large diameter (2*R*coil ~ 14mm) flat-coil technique [18].

Such a *SFCO*-probe may also "*notice*" and distinguish details of the relief of the normal-metallic object – with about 10µm spatial-resolution, presently (**Fig.12**). In order to demonstrate that, we performed an experiment with one-dimensional (**1D**) metallic grid made of 6 copper wires (see **Fig.12a**): each wire was 20-30m in dia. and was positioned with an average interval of about 200m between the wires. Copper wires distort the coil *RF*-field configuration when they move (*or*, *when the coil moves relative to the grid*), leading to changes of the oscillator frequency or/and amplitude. The effect is maximum when each wire reaches to the coil center. **Fig.12b** illustrates detected dependence of the oscillator frequency shift, *(F)*, vs. the lateral position of the metallic-comb relative to the flat-coil face (*relative to "magneticfield" probe*). Average distance between the detected 6 vertical neighboring peaks on the curve in **Fig.12b** is 200m just in agreement with the experimental setup in **Fig.12a**. That is why, we believe, that *SFCO***-**probe may also in future distinguish (*both by amplitude and frequency of the TD-oscillator*) details of the relief of the magnetic or metallic 2D grids, in *sub*micrometer scales. For such high lateral resolution, there is need to work out and create the *SFCO* method-based advanced "*magnetic-field*" probe, with a lithographically made singlelayer flat coil of about 1mm in diameter [23] – *as an effective needle-type probing instrument with better than* 100nm *predicted lateral resolution*. Such a radically new probe will have considerably *large work-distances* (more than 100m) *between the probe and surface of the object*, which enables a "visual" control of the local area of probing of the object, and, if needed, application of test perturbations (for example, exposition to laser radiation).

*in military science, engineering and Intelligence:* to detect onset and amount of attacking soldiery of enemy arm-forces in the absence of direct visibility, and to reveal and detect lowpowered nuclear weapon tests. Besides, to solve the perimeter or/and zone-security problems for the intelligence group(s), as well as for the special mission unit(s).

*In a precision sensor industry:* for creation of non-contact acceleration sensors (*the pickups*) of *super-*high resolution.

Fig. 12. Dependence of the *SFCO* technique's *TD* oscillator frequency shift *(F)[kHz]* (**b**) on the lateral position of the *1D* grid-shaped metallic object (**a**) relative to the "*probe-formative*" flat coil face.

*in a basic research:* for high-precision measurements of the Casimir Force and very little friction related with it. Besides, high- and/or low-*T*c superconductive coil-based 3D analogue of such a new, ultra-sensitive *SFCO-*position sensor seems to be very useful also for the *sub*-Angstrom *spatial-*resolution gravity-wave detection.
