FROM LETTERS TO THE EDITOR

ON THE HISTORY OF X-RAY MICROSCOPY AND MICRORADIOGRAPHY

For the purpose of correcting an error made in Yu.’s note “New methods for detecting defects in crystals”*), as well as in the recently published book Rentgenografiya by Umanskii, Kitaigorodskii, and Trapeznikov, I ask that the following be published:

In 1936, in the Journ. de Phisique et le Radium (p. 471), a paper by Bačkovskii (now director of a physical institute in Prague) was published, in which a method was described for obtaining X-ray photographs of a crystal surface by means of a spectrograph with Bragg focusing, with rocking of the crystal but with a stationary photographic plate. Under these conditions Bačkovskii succeeded in obtaining photographs on which, as the asymmetry of the instrument increased, the side of the reflecting plane of the crystal became quite clearly visible.

I somewhat modified and improved Bačkovskii’s method by using a sharply asymmetric spectrograph with a stationary crystal. As a result of using stationary crystals and photographic plates, I was able sharply to reduce the exposure (to 10–15 minutes) and at the same time to increase extraordinarily the sharpness of the image. The numerous photographs of crystal surfaces obtained by me have, in quality, still not been surpassed by anyone. At that time I also obtained magnifications of these photographs. In 1939 this work was included as a part of my doctoral dissertation, which was defended before the Council of the Engineering-Physics Faculty of the Leningrad Polytechnic Institute. Later this part of the dissertation was published by me in the Journal of Experimental and Theoretical Physics, 1940, Nos. 1 and 2. At the same time, together with my collaborators E. E. Vainshtein and M. N. Flerova, I developed a method for studying the structure of the surface of a bent crystal in Ioganson’s spectrograph (Journal of Experimental and Theoretical Physics, 1940, No. 3). The presentation of this work was given by E. E. Vainshtein in Uspekhi Fizicheskikh Nauk in 1940–1941. He also published in Priroda (1947, No. 2) a note entitled “X-ray spectroscopic study of the surface structure of natural and deformed crystals,” in which he gave due credit to my priority. Since then, in 1947 and 1950, at the Fedorov sessions in Leningrad at the Mining Institute, in the presence of a large number of Soviet X-ray specialists, I reported on my work in this field. Unfortunately, the 1947 report was not printed, and the 1951 report is still in press, in the Proceedings of the All-Russian Mineralogical Society.

*) UFN, vol. XL, 1, 1950.

In 1949 Ivanov published a review in the Journal of Technical Physics, No. 11, under the title “Microradiography,” in which he described a method entirely analogous to my own, but with reference to Barret’s article and without mention of my priority. I immediately wrote a letter of protest to the journal’s editorial office; it was published in the Journal of Technical Physics, 1951, No. 1, in the letters-to-the-editor section.

However, my letter passed completely unnoticed, and Barret, who had introduced only minor changes into the method I had proposed, is still being cited not only in foreign literature but sometimes also in Soviet literature as the author of so important a research method as diffraction X-ray microscopy, which in fact had been almost completely developed by me.

In parallel with the development of the method for investigating the structure of a crystal surface in monochromatic light, I was also developing methods of investigation in white light by reflection of white light from a crystal. These methods also entered into my doctoral dissertation as one of its parts and were briefly published in the form of a series of consecutive articles: D. Gogoberidze, Methods for reducing exposure in photographing Lauegrams, Transactions of the Laboratory, 1938, issue 12; D. Gogoberidze, On the question of the splitting of spots in Laue radiographs. Journal of Technical Physics, 1939, issue 3; D. Gogoberidze, Some new methods for photographing Lauegrams. Journal of Experimental and Theoretical Physics, 1940, issue 8.

In general, these methods yield results worse than those of investigation in monochromatic light—there is less sharpness and contrast of the image—but they offer the convenience that setting the surface of the crystal into the reflecting position is carried out more easily and more quickly, although the actual exposure takes much longer.

I subsequently cultivated these methods little, and I basically gave preference to methods of work in monochromatic light; all the more surprising it was to me when Guinier mentioned in his works my attempts in this respect, and still more surprising when a note by Yu. appeared in Advances in the Physical Sciences, in which Guinier’s work was cited without mention of my works.

D. B. Gogoberidze