Vibrating superconductors

This review is concerned with effects in the energy dissipation and elastic modulus of superconductors vibrating in a magnetic field. The physics of superconducting vibrating reeds and reeds made of superconducting suspensions is thoroughly described as well as the main features observed in other oscillators applied to flux pinning studies. It is argued that among the diversity of methods to study superconducting and pinning properties as a function of magnetic field and temperature, the vibrating reed technique is one of the most sensitive due to the accurate measurement of frequency and dissipation with feasible magnetometry applications. Results of the elastic coupling between the flux line lattice and the atomic lattice in high- and low-T _c superconductors obtained with the vibrating reed are summarized as well as the behavior of vibrating type II superconductors near their lower critical field. Results from mechanical measurements in high-temperature superconductors are reviewed, which support the model of thermally activated depinning and vortex diffusion.     

Vibrating wires for beam diagnostics

A new approach to the technique of particle beam scanning by wires has been developed. The novelty of the method is that the wire heating quantity is used as a source of information about the number of interacting particles. The wire heating measurement is performed as a change of the wire natural oscillation frequency. The excitation of wire natural oscillations is provided by interaction of a current through the wire with a permanent magnetic field. A shift in the wire natural oscillation frequency characterizes the change in the conditions of wire irradiation by the measured beam. By the rigid fixing of the wire ends on the support an unprecedented sensitivity of the frequency to the temperature and to the corresponding flux of colliding particles is obtained. The range of frequencies used (about 10 kHz) and characteristic time of heat transfer limit the speed characteristics of the proposed scanning method; however, the high sensitivity makes it a prospective one for investigation of beam halo and weak beam scanning. Traditional beam profile monitors generally focus on the beam core and loose sensitivity in the halo region where a large dynamic range of detection is necessary. The scanning by a vibrating wire can also be used in profiling and detecting of neutron and photon beams.     

振弦式硅微机械陀螺

提出了一种新的振弦式硅微机械陀螺的设计方案,这一陀螺的制作采用硅微机械工艺.一方面,陀螺驱动模块采用电磁力驱动,这样能极大地提高驱动幅度;另一方面,陀螺检测模块采用差分的双振弦方式,从而提高了检测精度.通过陀螺检测模块的振弦将角速度的变化直接转换成输出信号的频率变化,这样能够极大地提高信号的抗干扰能力.理论分析表明,这...     

微小型振弦式数字陀螺

本文在作者原有的研究基础上提出了微小型振弦式数字陀螺的设计方案,这一陀螺结构简单,并且可以采用传统的精密机械加工工艺来制作,因而成本低廉。本文给出了微小型振弦式数字陀螺的基本结构,并分析了其工作原理和主要特性指标。     

机械零件振动的可靠性设计

以传统的振动设计方法为基础,提出了机械零件振动的可靠性设计方法。把机械零件的固有频率、激振力频率、振动响应按照实际处理为随机变量,使用概率设计法确定机械零件振动设计的可靠度。文中介绍了机械零件振动设计量分布参数的确定方法和避开(或落入)共振、限制振动响应、避开流体诱发振动的可靠性计算模型。给出了旋转机械的转子、叶片、轴承、壳体、热交换器的管束和振动机械的可靠性设计分析方法和一些应用实例。