The dissertation is devoted to the theoretical synthesis and new solution of the scientific problem of technology and equipment improvement of the combined electron-beam processing of optical elements.
To implement the combined electron beam processing (combination of resistive method of deposition of thin coatings and electron beam processing in one technological cycle) the modernization of technological vacuum equipment and technological equipment (Pierce electronic gun, forming a tape-shaped electronic stream, resistive evaporator, electronic evaporator, mechanism for moving optical plates, quartz heaters for preheating and final cooling, high-voltage power supply, electronic flow control system and electronic control system -radiation processing).
A number of methods have been developed, namely: the method of modifying the surfaces of combined electron beam processing optical materials (determines the technological sequence of operations in combined electron beam processing optical elements to obtain high quality surfaces), the method of assessing the surface quality of optical elements by atomic force microscopy (determines the surface quality of optical elements). technological modes that provide minimal roughness of the treated surface). A method for diagnosing and controlling the current density distribution of a low-energy electronic stream of tape shape is proposed, which allows to automatically determine the spatial and energy characteristics of the parameters of the tape electronic stream directly in the process of electron beam processing. The use of an automated system of flexible control of electron-beam processing modes allows to control the specific power directly during the operating cycle and change its distribution by changing the voltage on the modulator, which leads to increased accuracy (5… 8%) and repeatability (2.2… .2.5 times) the results of processing.
To understand the processes that occur as a result of the interaction of the electron flow with thin films on optical glass, a mathematical model for determining the spatial temperature distribution in such a system is built.
Тhis model which takes into account the geometric and energy parameters of the electron flow obtained in real time and by means of which the distribution of thermal fields in an optical element is operatively determined.
A computer model of the Pierce electronic gun of a given design is constructed, and the calculations of the electrostatic field and the trajectory of the electrons are performed, taking into account the influence of the bulk charge and the initial velocity. To increase the efficiency (the ratio of the current of the electronic flow, which falls to the total current of the electronic flow), the voltage is controlled on the modulator, which will increase the efficiency of the electronic flow and change its shape.
As a result of probing the electron flow of the tape shape, it was found that at different parameters of the Pierce gun in practice there are different laws of current density distribution, which are different from the Gaussian distribution. This is due to the differences in the design of the electron beam gun from the ideal optics of Pierce. Probing the electron flow in the process of combined electron beam processing will allow you to control and manage the parameters of the electron flow, which will improve the quality of optical elements.
The use of combined electron-beam treatment leads to improved surface of thin films (increased structure homogeneity and reduced microdefects, reduced average surface roughness, thin films obtained by the basic technology have more zones with high mechanical stresses, compared to thin films obtained by the technology obtained). It is established that after electron beam processing the sensitivity of the elements of PPR devices increases 1.7 times.
The results of the work have found practical application in domestic and foreign enterprises.
