measurea

Measurement Axion (Spin) Fields

(Continuation, beginning in N1/98)

For measurement of axion fields it is meaningful to alter an active element of the generator described in N2/97, how, it is shown on Fig.1. It is necessary to execute electrodes 3, 4 and 5 from tin or aluminium, and to ensure a good contact to a surface of a ferrite tube. The ferrite is necessary for choosing with the greatest possible magnetic permeability and specific electrical resistance.

Fig.1

Fig.2

On electrodes 3 and 5 the variable voltage by amplitude 10 - 50 volts relative to an electrode 4, and frequency 300 - 1500 kHz (thickness of walls of a ferrite tube 1 - 4 mm) through the scheme represented on Fig.2.

By set-up of the balance capacitor C and resistor R, it is necessary to achieve minimum value of voltage on of a winding 1,2 at absence of axion field.

The variable voltage on electrodes 3,4 and 5, deflect THREADS fxion fields passing through a ferrite tube in parallel its axis, to its centre, to its perimeter. It is equivalent to periodic input and output of an coil with a current in a ferrite tube. The parameters of a design are necessary for choosing proceeding from the assumptions that the equivalent current of THREADS of axion field can reach 10^-12 - 10^-15 ampere with internal electrical resistance 10¹⁴ - 10¹⁶ ohm. Naturally, are effective a current can be amplified, and the resistance is reduced by two - three order if to use the scheme of feedback on axion field as it is offered in N1/98.

Together with variable voltage, on contacts A and B it is desirable to submit adjustable constant voltage for displacement axion of THREADS to working area of the detector (wall of a ferrite tube).

Fig.3

Axion fields with a small longitudinal momentum can be modulated using three-layered the capacitor with plate from a thin aluminium foil 3,4,5 (Fig.3) and polyethylene-terephthalate dielectric.

Plate 3 and 5 ground, and on plate 4 the pulsing positive voltage ensuring periodic choking axion of a beam directed through the capacitor and ferrite tube on its axis moves. Thus of polyethylene-terephthalate dielectric allows on the order to lower choking voltage.

At such design of the modulator, there is no necessity for electrodes covering a ferrite tube, but, for adjustment of a position of THREADS of axion field in working area of the detector (the walls of a ferrite tube), are necessity to pass a current of displacement through a measuring winding 1,2 (on 1 moves +).

In the given design, also it is meaningful to use the scheme of introduction of feedback on axion field as it is offered in N1/98.

At measurement, the largest problem will be the coordination of large internal "electrical" resistance of axion field with input resistance of the measuring device and stray capacitance of a design. On idea, the detector should execute a function transformer with a large factor of downturn of voltage (~10⁹), i.e. the measuring winding 1,2 should contain much less than one turn of a wire. How it to make? It can be made by breaking all magnetic flow, in walls of a ferrite tube, on set of fragments covered by one turn as it, for example, is shown on Fig.4 or 5.

Fig.5

Fig.4

The arrangement of turn of a winding 1,2 should provide minimum inter-turn capacitance.

Fig.6

To operate a axion field it is possible also by magnetic field (passing an variable current through an electrical winding 5,6), using for measurement the differential scheme (on cleat 1,2,4). But thus, it will be necessary to apply many efforts on electrical (and magnetic) balancing of a measuring circuit.

As the core 3 it is possible to use a ferromagnetic film and there is no special sense to adhere to the form toroid. So, for example, it is possible toroid on Fig.5 and 6 to compress from sides and to reel by it a spiral. Then, densely by compressing turn of a ferromagnetic film to generate set of the local closed magnetic circuits with the magnetic wind (thus, increasing effectiveness of use of volume of the detector), etc.

(see N3/95 , N5/95 , N2/96 , N3/96 , N2/97 , N1/98 , N1/99 , N2/99)

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