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ABSTRACT X-RAY images of the Sun have recently been obtained in a number of relatively narrow wavelength bands below 20 Å. The instrument consisted of a gas-filled proportional counter with

a six channel pulse-height discriminator to provide energy resolution1. To provide spatial resolution and increase the collecting area of the detector a method discussed by Giacconi and

Rossi was used2. This involved the use of a grazing incidence paraboloidal mirror, a small stop in the focal plane of which limited the field of view to a half-angle α = _r_/(1–_d_) (Fig.

1). By a suitable choice of _r_ the field of view was reduced to a fraction of that subtended by the whole Sun. An image was built up by scanning the instrument in a systematic way across

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2021 REFERENCES * Boyd, R. L. F., _Space Sci. Res._, 4, 35 (1965). ADS  CAS  Google Scholar  * Giacconi, R., and Rossi, B., _J. Geophys. Res._, 65, 773 (1960). Article  ADS  Google Scholar 

* Rugge, H. R., and Walker, A. B. C., _Space Res._, 8, 439 (1968). Google Scholar  * Evans, K., and Pounds, K. A., _Astrophys. J._, 152, 319 (1968). Article  ADS  CAS  Google Scholar  *

Mandelstam, S. L., _Space Sci. Rev._, 4, 587 (1965). Article  ADS  Google Scholar  * Underwood, J. H., and Muney, W. S., _Solar Phys._, 1, 129 (1967). Article  ADS  Google Scholar  Download

references AUTHOR INFORMATION AUTHORS AND AFFILIATIONS * Department of Physics, University College, University of London, C. R. NEGUS & W. M. GLENCROSS Authors * C. R. NEGUS View author

publications You can also search for this author inPubMed Google Scholar * W. M. GLENCROSS View author publications You can also search for this author inPubMed Google Scholar RIGHTS AND

PERMISSIONS Reprints and permissions ABOUT THIS ARTICLE CITE THIS ARTICLE NEGUS, C., GLENCROSS, W. Spatial Variability of the Solar X-ray Spectrum below 20 Å. _Nature_ 220, 48–50 (1968).

https://doi.org/10.1038/220048a0 Download citation * Received: 09 August 1968 * Issue Date: 05 October 1968 * DOI: https://doi.org/10.1038/220048a0 SHARE THIS ARTICLE Anyone you share the

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