Numerical simulation of thermal effect influenced by incident angle in the ion beam figuring

Ion beam has the advantages of high accuracy and little damage to components, which has been widely used in the figuring of optical components. However, in figuring, the collision between the ions with high-speed collides and the surface of the optical component will cause the temperature of the optical component to rise quickly. In order to investigate the thermal effect of the ion beam figuring, the thermal deposition model is established based on the Sigmund theory of sputtering, and the thermal power density function of the surface heat source is obtained. On this basis, taking BK7 glass as the research object, Monte Carlo method was used to obtain the total power of thermal deposition under the different incidence angle of ion beam. Then the finite element method was used to simulate the thermal effect of the ion beam figuring. The result shows that the deposition energy, maximum temperature and the maximum stress decrease with the increase of incidence angle, and the maximum stress appeared in the clamping position of fixture. The corresponding simulation result shows that comparing with the fixing fixture, the maximum stress in the optical component could be reduced more than 70% by using elastic fixture.