Experimental Research on Micro-electroforming for Fabricating Cantilever Used in Micro-machined Tunneling Gyroscope

悬臂梁式微机械隧道陀螺仪是一种以悬臂梁作为换能构件，以电子隧道效应作为输出敏感方式的高精度和高灵敏度的角振动传感器，解决了传统微机械陀螺仪因尺寸减小而导致的灵敏度降低的缺点。加工工艺是制约其产业化的关键。悬臂梁是其核心构件，它将输入的角速度转为梁的振动位移，为了达到高的响应频率和输出，悬臂梁应达到一定的厚度和尺寸精度，这给悬臂梁的制作带来一定的难度。本文利用近紫外线厚胶光刻和微电铸的方法实现悬臂梁的制作，主要的研究工作包含如下几个部分：  根据微机械隧道陀螺仪的工作原理和悬臂梁的结构特点，分析制作要求和工艺难点；查阅资料了解当前主要的MEMS加工工艺，特别是三维结构的加工，选...Micro-machined tunneling gyroscope with cantilever is a kind of angular rate sensor with high sensitivity and resolution, in which cantilever works as transducer and electron tunneling effect is employed as sensor. It overcomes the traditional one’s reduction in sensitivity when miniaturized. The fabrication problem is the key issue impeding its commercialization. The cantilever is the critical co...学位：工学硕士院系专业：物理与机电工程学院机电工程系_测试计量技术及仪器学号：20012900

A new measurement of the K-+/- -> pi(+/-)gamma gamma decay at the NA48/2 experiment

The NA48/2 experiment at CERN collected two data samples with minimum bias trigger conditions in 2003 and 2004. A measurement of the rate and dynamic properties of the rare decay K-+/- -> pi(+/-)gamma gamma from these data sets based on 149 decay candidates with an estimated background of 15.5 +/- 0.7 events is reported. The model-independent branching ratio in the kinematic range z = (m(gamma gamma)/m(K))(2) > 0.2 is measured to be B-MI(z > 0.2) = (0.877 +/- 0.089) x 10(-6), and the branching ratio in the full kinematic range assuming a particular Chiral Perturbation Theory description to be B(K-pi gamma gamma) = (0.910 +/- 0.075) x 10(-6). (C) 2014 The Authors. Published by Elsevier B.V. This is an open access article under the CC BY license (http://creativecommons.org/licenses/by/3.0/)

Study of the K-+/- -> pi(+/-)gamma gamma decay by the NA62 experiment

A study of the dynamics of the rare decay K-+/- -> pi(+/-)gamma gamma has been performed on a sample of 232 decay candidates, with an estimated background of 17.4 +/- 1.1 events, collected by the NA62 experiment at CERN in 2007. The results are combined with those from a measurement conducted by the NA48/2 Collaboration at CERN. The combined model-independent branching ratio in the kinematic range z = (m gamma gamma/m(K))(2) > 0.2 is B-MI(z > 0.2) = (0.965 +/- 0.063) x 10(-6), and the combined branching ratio in the full kinematic range assuming a Chiral Perturbation Theory description is B(K-pi gamma gamma) = (1.003 +/- 0.056) x 10(-6). A detailed comparison of the results with the previous measurements is performed. (C) 2014 The Authors. Published by Elsevier B.V

Search for the dark photon in pi(0) decays

A sample of 1.69 x 10(7) fully reconstructed pi(0) -> gamma e(+)e(-) decay candidates collected by the NA48/2 experiment at CERN in 2003-2004 is analyzed to search for the dark photon (A') production in the pi(0) -> gamma A' decay followed by the prompt A' -> e(+)e(-) decay. No signal is observed, and an exclusion region in the plane of the dark photon mass m(A') and mixing parameter epsilon(2) is established. The obtained upper limits on epsilon(2) are more stringent than the previous limits in the mass range 9 MeV/c(2) pi(+/-)A' decay is also evaluated. (C) 2015 The Authors. Published by Elsevier B.V