In order to put the Pulse Line Ion Accelerator （PLIA） concept to its practical application, a small experimental platform was built. It was found that the actual axial electric field is smaller than the theoretical ...In order to put the Pulse Line Ion Accelerator （PLIA） concept to its practical application, a small experimental platform was built. It was found that the actual axial electric field is smaller than the theoretical calculation, so the accelerated ions will enter into the deceleration zone before leaving the helix, which will seriously affect the acceleration process. Based on the improved parameters, the He＋ with 24 keV is accelerated to 55 keV, and the proof-of-principle experiment is completed on this platform.展开更多
ITD(Ibrahim Time Domain)法利用结构自由振动响应,通过3次不同延时的采样,建立特征方程,求解结构的模态参数。延时采样过程中,时延的取值与模态参数识别精度息息相关,因此需要对ITD法的时延展开研究。通过理论分析推导出时延为采样间...ITD(Ibrahim Time Domain)法利用结构自由振动响应,通过3次不同延时的采样,建立特征方程,求解结构的模态参数。延时采样过程中,时延的取值与模态参数识别精度息息相关,因此需要对ITD法的时延展开研究。通过理论分析推导出时延为采样间隔的倍数应小于采样频率为系统最大固有频率的倍数的一半。利用数值仿真及悬臂梁实验验证了该理论,分析了噪声环境下时延变化对模态参数识别的影响规律。结果表明,适当增大时延能提高ITD法的模态参数识别精度,降低噪声模态的影响。展开更多
基金Supported by National Natural Science Foundation of China(10921504,11105197,11105195)Knowledge Innovation Project of Chinese Academy of Sciences(Y115280YZD)
文摘In order to put the Pulse Line Ion Accelerator （PLIA） concept to its practical application, a small experimental platform was built. It was found that the actual axial electric field is smaller than the theoretical calculation, so the accelerated ions will enter into the deceleration zone before leaving the helix, which will seriously affect the acceleration process. Based on the improved parameters, the He＋ with 24 keV is accelerated to 55 keV, and the proof-of-principle experiment is completed on this platform.
文摘ITD(Ibrahim Time Domain)法利用结构自由振动响应,通过3次不同延时的采样,建立特征方程,求解结构的模态参数。延时采样过程中,时延的取值与模态参数识别精度息息相关,因此需要对ITD法的时延展开研究。通过理论分析推导出时延为采样间隔的倍数应小于采样频率为系统最大固有频率的倍数的一半。利用数值仿真及悬臂梁实验验证了该理论,分析了噪声环境下时延变化对模态参数识别的影响规律。结果表明,适当增大时延能提高ITD法的模态参数识别精度,降低噪声模态的影响。
