X-ray Structures of the Sun during the Importance 1N Flare of 8 June 1968.

High-resolution solar x-ray images were obtained with a rocket-borne grazing incidence telescope. The x-ray flare is large in extent, has fine strulctuire, and follows a neutral magnetic line. X-ray emitting coronal links interconnect active regions. The general coronal emission at the limb and several faint regions on the disc are observed.

Orthogonal Mirror Telescopes for X-ray Astronomy.

Crossed mirror telescopes are presented as an alternative to the present telescope systems used in x-ray astronomy. These instruments generally have a higher x-ray collecting efficiency but a poorer angular resolution than the more conventional paraboloid-hyperboloid telescopes. They also can be made more easily and quickly as was demonstrated by a recent rocket flight that used a simplified mirror design with only one-dimensional focusing.

Background suppression in double-beam interferometry.

An optical background suppression technique is described in which the lower spatial frequencies of a background field are effectively suppressed, thereby enhancing the detectability of localized sources. The technique is particularly applicable for use in image-forming double-beam interferometers in which the individual detector elements are matched to the diffraction-limited resolution of the instrument. The technique uses pairs of optical systems whose modulation transfer functions are suitably matched, and a number of these pairs are described.