The algorithm for solving the problem of local surface shape errors correction by small-size ion beam is proposed in the paper. The algorithm involves a sequential search of heights relative to the average value with the aim to find the most optimal etching point that satisfies the criterion - reducing the sum of the modules of the derivatives on the etching spot. It is shown that the new approach makes it possible to significantly expand the range of spatial frequencies that can be influenced at a given size of the ion beam.

Описаны методики прецизионной обработки поверхности оптических элементов пучками ускоренных ионов. Приведены характеристики и возможности оборудования, а также решаемые с помощью него задачи. Подробно описаны возможности финишной коррекции локальных ошибок формы малоразмерным ионным пучком, осесимметричной коррекции/асферизации широкоапертурным сильноточным ионным пучком и ионной полировки. Представлены значения эффективной шероховатости поверхности плавленого кварца, ситалла, Zerodur'а, ULE в диапазоне пространственных частот q[2.5·10-2-6.0·101 μm-1], а также примеры формирования сферической поверхности и профиля асферизации. Ключевые слова: ионно-пучковая методика, пучок ускорения, кварц, ситалл.

The paper presents the results of studying the energy dependences of the sputtering coefficient and the effective surface roughness of single-crystal silicon irradiated with neon ions with an energy of 100-1000 eV. As a result of the work, the parameters of ion-beam etching with accelerated Ne ions were determined, providing a high sputtering coefficient (etching rate) and an effective roughness value in the spatial frequency range 4.9∙10-2-6.3∙101 μm-1 less than 0.3 nm for the main cuts of single-crystal silicon (<1 0 0>, <1 1 0> and <1 1 1>).

The paper proposes the use of diamond-carbide-silicon composite "Skeleton"® coated with amorphous silicon as substrates for multilayer X-ray mirrors for powerful synchrotron radiation sources (3rd+ and 4th generation). The surfaces with the following parameters were obtained using standard deep polishing methods: flatness at the level of RMS90%=54.2 nm; effective roughness sigmaeff~1.0 nm; high-frequency roughness sigma2х2~0.1 nm.

The paper demonstrates the pulse mechanism of physical sputtering taking into account the evolution of the surface. The model is based on pulsed energy transfer in collision cascades. The main feature is the consideration of surface roughness. The results of numerical simulation qualitatively coincide with those observed in experiments. It is shown that the angular dependences calculated in the framework of this model have closer values of the sputtering yields to the experimental ones than those calculated in TRIM.