LETTERS TO THE EDITOR

REGARDING THE ARTICLE BY F. DANIELS, C. BOYD, AND D. SAUNDERS “THERMOLUMINESCENCE AS A TOOL FOR SCIENTIFIC RESEARCH”

In the journal Uspekhi Fizicheskikh Nauk, Vol. LI, No. 2, 1953, a translation was printed of the above-mentioned article by the American authors Daniels, Boyd, and Saunders (Science 117, 343 (1953)), in connection with which it is necessary to make the following comments.

1. The article completely passes over in silence the works of Soviet physicists on the study of electronic local trapping levels in crystal phosphors and, in particular, the works on the creation and development of the method of thermally stimulated glow curves, which is the principal method for their investigation. Pointing out that thermally stimulated glow curves were first obtained by Urbach in 1930, the authors further state that the method of thermally stimulated glow curves was subsequently improved by Randall and Wilkins in 1945 and by Boyd in 1949. Meanwhile, it is known that this method received substantial development in 1939 in the work of M. L. Katz and R. E. Solomonik (DAN 34, 682 (1939)) and in the author’s subsequent works devoted to the study of thermally stimulated glow in x-rayed crystals of alkali-halide compounds.

In 1941 I completed a detailed investigation of thermally stimulated glow in the visible and ultraviolet regions of the spectrum, and indicated a method for calculating the depths of local energy levels from thermally stimulated glow curves. In the same year the work was reported at a colloquium at the Odessa Institute of Physics, but since the materials remained during the war in temporarily occupied Odessa, they could be published only after the war, about which an appropriate note was made in the article (ZhETF 18, 501 (1948)).

The experiments of A. N. Brilliantov and Z. L. Morgenshtern (ZhETF 8, 401 (1938)) on the thermally stimulated glow of rock salt are directly related to the method under consideration, although their observations were not expressed in the form of thermally stimulated glow curves. In 1940 M. N. Dyatchenko applied the method of thermally stimulated glow curves to the investigation of the luminescence of x-rayed rock-salt crystals (ZhETF 10, 288 (1940)). Finally, V. V. Antonov-Romanovskii for the first time in 1946 gave a detailed theoretical analysis of the method of thermally stimulated glow curves on the basis of the bimolecular mechanism of luminescence (Izv. AN SSSR 10, 477 (1946)).

Thus, we have the right to assert that, in essence, the method of thermally stimulated glow curves was first developed in the Soviet Union. However, in the review article by Daniels, Boyd, and Saunders there is no ...

contains not a single reference to our work. It should be noted here that, in addition to those mentioned above, there are a number of other works by Soviet physicists in which the method of thermal bleaching found wide application and was further developed in the study of the energy localization levels and the mechanism of luminescence of crystal phosphors (see, for example, V. V. Antonov-Romanovskii, V. L. Levshin, Z. L. Morgenshtern, Z. A. Trapeznikova, Izv. AN SSSR, Ser. Fiz. 13, 75 (1949); V. V. Antonov-Romanovskii, DAN 68, 457 (1949); A. I. Parfianovich, ZhETF 21, 1389 (1951); M. L. Kats, DAN 58, 1935 (1947); ZhETF 23, 720 (1952); M. L. Kats and A. S. Andrianov, DAN 61 (1948), etc.).

1. Speaking of the thermoluminescence of colored crystals of alkali-halide compounds containing no extraneous activators, Daniels, Boyd, and Saunders cite an unpublished doctoral dissertation by the American Heckelsberg, completed in 1951, so that the reader is given the false impression that the thermal bleaching of the indicated crystals was investigated by them for the first time. However, thermal bleaching and luminescence of crystals of alkali-halide compounds containing no extraneous activators were first studied in detail in works by the author published in the period from 1936 to 1952 (Nature 138, 833 (1936); Sow. Phys. 12, 373 (1937); ZhETF 8, 100 (1938); DAN 58, 1637 (1947); Izv. AN SSSR, Ser. Fiz. 15, 667 (1951); ZhETF 22, 78 (1952), etc.).

Not knowing, or consciously suppressing, the works of Soviet authors, Daniels, Boyd, and Saunders attribute to themselves or to other American investigators long-known facts established and expounded in works published by us. Thus, for example, the aforementioned authors write in their article: “if alkali halides are irradiated at the temperature of liquid air, then new peaks appear on the glow curve at low temperatures,” and cite Heckelsberg’s dissertation (1951), despite the fact that this phenomenon was studied in detail by Kats and Solomonkov as early as 1939 in the work mentioned above.

Further, the authors report that they have “completed preliminary work on studying the influence of impurities on thermoluminescence” (p. 276), and as an example they indicate that in sodium chloride containing 1 mol.% silver chloride, the intensity of thermoluminescence increases 100-fold. The thermoluminescence of such phosphors has also been studied in detail by Soviet physicists (A. Polonskii, DAN 21, 15 (1938); A. I. Parfianovich, ZhETF 19, 605 (1949); M. L. Kats, DAN 85, 539 (1952)).

Finally, it should be noted that Daniels, Boyd, and Saunders investigated the thermoluminescence of alkali-halide compounds only in the visible region, since the apparatus they used did not allow, as the authors themselves note, investigations to be carried out in the ultraviolet region (the luminescence intensity is low!). In the works of the author of these lines, however, the thermoluminescence of colored crystals of alkali-halide compounds was studied not only in the visible, but also in the ultraviolet region (see, for example, ZhETF 18, 501 (1948)) with the aid of a photon counter specially designed for this purpose (Sow. Phys. 9, 254 (1936)).

In general, it is known that some American researchers suppress the works of Soviet physicists and, not infrequently, while repeating or developing published works of Soviet investigators, provide no references whatsoever, or else provide them so reluctantly and in such a form as greatly to diminish their value. Daniels, Boyd, and Saunders have done just this.

M. L. Kats