The structure of the chromosphere along the northern limb of the Sun according to eclipse observations with RT-22 PRAO AKTs FIAN at a wavelength of 1.4 cm

An acute problem in the study of the solar chromosphere is the following obvious contradiction between the results of radio astronomical measurements of the height (extension) of the chromosphere and model calculations made on the basis of classical standard atmospheric models: the height of the chromosphere according to radio data is significantly greater than the model calculations. This is largely due to the fact that the widely used models are based on UV observations and, in addition, are one-dimensional and do not take into account the strong structural inhomogeneity of the chromosphere. Numerous attempts to ``improve'' the models by introducing various elements of inhomogeneity and ``fit'' them to radio data are purely empirical and are not substantiated theoretically. In such a situation, it is important to obtain more accurate and reliable radio observation data. This is all the more important because such data can serve as a basis for testing the recently developed 3D inhomogeneous theoretical models of the solar atmosphere. The article presents new data obtained from observations of a partial solar eclipse on June 10, 2021, using the RT-22 radio telescope of the Lebedev Physical Institute at a wavelength of 1.4 cm: the estimate of the radio radius is not more than 13''. The contradictions mentioned above remain significant.