DD202476A5 - EXTREMELY LIGHTWEIGHT, LARGE-LANDED COLLAR MIRROR WITH ELASTIC, MAGNETIC OR LIGHT-PRINTED ELASTIC MIRRORS - Google Patents

Abstract

Large-area paraboloidal mirror for concentrating sunlight or for imaging weak astronomical light sources by the elastic deformation of prestressed, mirrored, thin membranes, in which the longitudinally rigidly clamped membranes of their closed circumference are deformed either by electric, magnetic or light pressure action in the appropriate manner. In this case, for mirrors with relatively small focal lengths, the deformation forces can be generated by electric or magnetic fields with constant or sufficiently high frequency, for larger focal lengths - without the possibility of fine correction of Paraboloidabweichungen - by aufteffende light photons.

Description

Extremely light, large collecting mirror with electric, magnetic or light pressure deformed elastic mirrors

Field of application of the invention

The invention relates to an extremely lightweight, large-scale collecting mirror with elastic, magnetic or by light · deformable elastic mirrors for the production of solar energy on the earth and in space and for imaging optics in weightless space stations.

Characteristic of the known technical solutions

Since the electromagnetic light waves penetrate exponentially decaying into metallic mirror layers, an aluminum layer of

Δ ^{a 1 O} ' ^{S m}

Thickness to reflect more than 90 % of the incident, visible light au.

This allows the construction of material-saving mirror optics for solar energy production on the Srd.e and in space as well as astronomical imaging optics in weightless space stations. The required shaping has hitherto been based on technologies developed by us by forming an equilibrium surface of elastic reflecting film of negligible bending stiffness. This foil is attached to a circular

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clamped rigid ring and closes a flat disc-shaped space -ab, which is under negative pressure.

Under the flowed the tangential $ ~ ^ S of the membrane provides a Gleichgewichtaförm the mirror films by the differential equation

1- + JL = E- 2

"1 / ^ ₁ + 1 / β> i ^e Gaussian curvature and ρ is the normal pressure on the membrane. The mathematical relations are aind. in Pig »1 shown in perspective.

Object of the invention

The aim of the invention is to avoid the relatively high cost of generating the negative pressure »

Explanation of the essence of the invention

The object of the invention is to provide a weightlessness in space 'adapted large-scale collecting mirror, which allows a good concentration of large radiation power ·

This is inventively achieved by a large-scale mirror for the concentration of sunlight or for imaging weak astronomical light source, which consists of a biased Polie by the Maxwell's

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Tensile forces Cc £. electric fields the desired

    2 - optical form adopts »

The imaged or concentrating mirror can through the Maxwelüaihen Zagkräfte A-oH magnetic fields the

desired optical form or by the electro-

2 p

magnetic light pressure forces ~ - ·

The electric or magnetic fields can either be constant or oscillate at a sufficiently high frequency,

The mirror surface can advantageously be readjusted by mechanical shaping of the rear-side electrode surface and its electrical potential distribution »

It may also be expedient that the mirror surface can be toned by mechanical shaping of the back pole surface and its magnetic potential distribution »

Auaführungsbeispiel

The invention will be explained in more detail below with reference to embodiments »In the accompanying drawings show:

Fig. 1: the perspective view of the mathematical relationships of a known solution;

2 shows an embodiment of an electrically deformable mirror;

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I ¹ Xg. FIG. 3: an external form of a magnetically deformable mirror; FIG.

Xg. 4: A carrion shape of a light-deformable mirror.

According to the invention, according to. 2 the lorinal pressure ρ by the Maxwellian tensile stress

2 (4)

generated an electric field between the conductive mirror diaphragm (1) and suitable for this purpose _s-shaped counter electrode (2), "which is connected to the Hochspannungsqueile (3), forms"

For a typical field strength B = 1Cr Y / mm and

£ o = 8,859 «1CT ¹² 4§ is calculated ρ -. = 443

vm ö-LSK. "

By forming the counter electrode (2) into many individual electrodes with arbitrarily controllable potential distribution. can be inventively distribute the field strength E on the mirror electrode for the purpose of fine adjustment in the desired manner. The voltage source can represent a high DC or AC voltage sufficiently high frequency.

Analogous to the electrical pressure force distribution can be according to the invention according to FIG. 3, the Maxwellsehe tensile stress in the field direction of the magnetic induction

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= - H ² = 1 atm at B = 0.5 Desla Use deformation of magnetic mirror membrane.

For example, (5) represents the mirror membrane and (6) the mechanically adjustable counter pole, both of which are magnetically conductive. The constant field forming between (5) and (6) is generated by the permanent magnetic ring (7).

Because of the mentioned low mirror thickness S and thus low mass occupancy can be used according to the invention, the electro-magnetic sunlight pressure to Pig ... 4 for molding large solar concentrator mirror »

Because the light reflected by a mirror at angle cc is the pressure

^ exercises

with a luminous flux of S = 1.36 kW / m for the near-Earth

Space and the speed of light c = 3 · 10 m / sec is ρ = 9.4 10 ~ ⁶ I / m ² ,

Because of the weightlessness of unpowered space stations can in this way large collecting mirror for. Concentration of large radiation powers over also low-mass stiff edge rings (8) are stretched »

Claims (6)

Erfindungaanapruch Extremely light, large collecting mirror with elastic, magnetic or deformed by light pressure elastic mirrors, characterized in that the imaging or concentrable mirror consists of a prestressed foil, which by the Maxwellian tensile forces. ¹ electric fields assumes the desired optical shape. 2 p - = - takes the desired shape. 2 · Mirror according to item 1, characterized in that the imaging or concentrating mirror by the Maxwellian tensile forces magnetic fields assumes the desired optical shape. 3. Mirror according to item 1, characterized in that the Mirror by the electromagnetic light pressure forces 4. mirror according to the points 1 and 2, characterized in that the electrical or magnetic fields are either constant or oscillate at a sufficiently high frequency. , 5. Mirror according to item 1, characterized in that by mechanical shaping of the rear electrode (J O-7- 4.11.1982 61 083/17 surface and its electrical potential distribution, the mirror surface can be readjusted » 6. mirror according to item 2, characterized in that by mechanical shaping of the back pole face and its magnetic Potentialvertellung the mirror surface can be nachustiert. - For this. 1 page drawing -