US 4,740,276 A · Fabrication of cooled faceplate segmented aperture mirrors (SAM) by electroforming

Abstract

An electroforming method is described for making a cooled segmented aperture (SAM) mirror suitable for use with high energy laser irradiation. The method avoids the problems associated with discrete segment SAMs by using electroforming to fabricate a continuous faceplate having a surface shape of the desired array of segments and coolant channels just below the optical surface to provide improved performance under high energy laser irradiation. A master mirror is fabricated from discrete segments. Raised circular lands on the rear of the segments aid alignment of the segments. A negative faceplate is electroformed on the master mirror. A positive faceplate is electroformed on the negative faceplate. Cooling channels are electrical discharge machined into the back of the positive faceplate and additional material electrodeposited to close the channels. A manifold for coolant flow through the cooling channels and bosses for safety screws are attached to the back of the positive faceplate and held in place by a further electrodeposition. Large substrates are epoxy bonded to the electroformed negative and positive faceplate deposits before separation from their respective masters to prevent elastic deformation of the deposits. Separator bars are used to facilitate separation. The structure of the CSA mirror made from the method is also disclosed.

Claims16

Dependent claims

A method for making a cooled segmented aperture mirror tile, comprising the steps of:

(a) providing a master;
(b) electroforming a first layer of material onto the face of the master to form a negative faceplate having a front surface facing the master and a rear surface;
(c) bonding a first conforming substrate to the rear surface of the negative faceplate;
(d) separating the negative faceplate and substrate assembly from the master;
(e) electroforming a second layer of material onto the front surface of the negative faceplate to form a positive faceplate having a front surface facing the front surface of the negative faceplate and a rear surface;
(f) forming coolant channels in the rear surface of the positive faceplate;
(g) electrodepositing a third layer of material over the second layer to enclose the coolant channels;
(h) opening passages through the third layer to the coolant channels;
(i) positioning at least one manifold against the third layer so that the manifold operative interconnects to the coolant channels through the opened passages;
(j) electrodepositing a fourth layer of material over the third layer and manifold to attach and seal the manifold to the third layer;
(k) bonding a second conforming substrate to the fourth layer, the second conforming substrate having an opening for the manifold;
and,
(l) separating the positive faceplate from the negative faceplate, whereby the positive faceplate, third and fourth layers, manifold and second substrate comprise the mirror tile.

10 more elements

Dependencies are inferred from the claim text.

Fabrication of cooled faceplate segmented aperture mirrors (SAM) by electroforming

Life of this patent

Fabrication of cooled faceplate segmented aperture mirrors (SAM) by electroforming

Life of this patent

Abstract

Claims16