石英谐振加速度计振梁内部热应力的抑制方法研究

石英谐振加速度计具有抗干扰能力强、准数字输出和易于集成等优点，但温漂成为了制约其稳定性指标的关键因素。本文通过全石英无异质材料设计和热应力隔离结构方案有效抑制加速度计振梁内部产生的热应力。传感器敏感结构由惯性质量块、铰链、固定基底和微谐振器组成，均采用石英晶体材料制备，且两个微谐振器呈差动布置可以通过差分对振梁内热应力进行部分抑制。通过微谐振器的四边形框架设计可以将工作环境中产生的热应力与振梁隔离，再对固定基底上的热应力敏感部分进行拓扑优化设计来抑制工作时从固定锚点处传递至振梁内部的热应力。本文对石英谐振加速度计进行了全温度下的有限元仿真计算分析，工作环境温度从室温到75 ℃，微谐振器振梁内部产生的热应力经优化后减少了99.41%以上。     

A new approach for pulse amplitude measurement using Lagrange’s interpolation for radiation or particle detectors

In radiation detector signal processing, usually, the charge-sensitive preamplifier converts the small charge signal coming from the semiconductor-based detector into voltage form and then the signal is further amplified to measure the energy of the incoming radiation. The voltage pulse from a charge-sensitive preamplifier (CSPA) is amplified using a shaping amplifier which reduces the signal bandwidth. To achieve better energy resolution, precise measurement of the peak amplitude of shaping amplifier output is required. The signal processing methods are available in which the signal from the charge-sensitive preamplifier can be directly digitized using high-speed Analog to Digital Converters (ADC), and then further signal processing such as gain and shaping is carried out inside the Field Programmable Gate Arrays (FPGA). For multiple detector systems, digital signal processing methods are quite difficult to implement in Field Programmable Gate Arrays (FPGA). In this context, The development of an alternative technique is initiated that uses a charge-sensitive preamplifier, shaping amplifier, low sampling analog-to-digital converter, and FPGA, where LaGrange’s interpolation technique is implemented in FPGA to precisely measure the peak of the analog pulse. In this paper, the comparison of the proposed method with other pulse amplitude measurement techniques is discussed. Results show that the implemented technique gives similar energy resolution compared to digital pulse processing and standard peak detector-based techniques.