Effect of the particular temperature field on a National Ignition Facility deformable mirror

• The surface shape of a NIF deformable mirror is investigated under different temperature fields.
• The PV and RMS change with temperature field in a certain rule.
• Temperature response of the mirror helps us better control the ambient conditions in actual work.

The changes caused by temperature in the surface shape of a deformable mirror used at the National Ignition Facility has been investigated previously. In this paper the temperature induced surface shape under different temperature fields is further studied. We find that the changes of the peak and valley (PV) or root-mean-square (RMS) value rely on the temperature gradient as well as the difference between the mirror and the environment with a certain rule. This work analyzes these quantitative relationship, using the finite element method. Some experiments were carried out to verify the analysis results. The conclusion provides guidance to minimize the effect of the temperature field on the surface shape. Considerations about how to improve the temperature induced faceplate in actual work are suggested finally.