Design Of High Resolution Angular Trimmer For Monochromator

The synchrotron light source is a new high-performance intense light source with many advantages that traditional light sources do not have,and plays a key role in supporting research in many basic sciences.Usually,monochromators are used to monochromatize the synchrotron light source to meet the needs of different experiments.In the process of Bragg angular motion,the relative attitude of the two crystals directly affects the quality of the light emitted from the experimental station,which has a great impact on the experimental results.The two crystals need to adjust their attitude continuously during the whole process to ensure the smooth operation of the experiment,so the mechanism carrying the crystals needs to have the ability of high-resolution angle adjustment.At the same time,the mechanism also needs to be vibration-resistant to ensure the stability of the emitted light.Based on the above,two high-resolution angular trimming mechanisms for monochromators are designed in this paper.In this paper,we analyze the interference factors that the bicrystal monochromator will be subjected to in the process of use by means of finite element analysis,and combine them with engineering requirements to determine the index requirements that the angle trimmer mechanism needs to achieve.This paper first designs a trapezoidal four-link angle trimming mechanism,which is based on a four-link and a trapezoidal platform,combined with a flexible hinge to achieve high resolution and vibration resistance.In order to verify the reasonableness of the mechanism,a physical model was established to analyze its theoretical resolution and inherent frequency,and then verified by means of finite element analysis.After confirming the reasonableness of the model,the trapezoidal four-link mechanism is optimized by this model,and its performance is ensured by changing key parameters.After the analysis of the trapezoidal four-link angle trimming mechanism,this paper designs an angle trimming mechanism based on the bridge amplification mechanism,which has better vibration resistance and can achieve linear angle adjustment compared with the trapezoidal four-link angle trimming mechanism.In this paper,the physical model of the mechanism is also established,its rationality is verified by finite element simulation,and its optimization is carried out under the condition that the model analysis is reasonable.After completing the above work,an experimental prototype of the trapezoidal four-link angle trimmer mechanism was fabricated and tested in this paper.The experimental test results show that the trapezoidal four-linked rod angle trimming mechanism in the case of step size1μrad,the resolution average step size between 0.988μrad and 1.032μrad,the standard deviation is less than 0.08μrad;grating closed-loop repeatability is less than 0.365μrad,closed-loop self-collimator repeatability is less than 0.476″;the first-order inherent frequency is63 Hz.All the indexes meet the requirements of the monochromator,which further illustrates the reasonableness and feasibility of the mechanism.