A prototype of a laser driven proton accelerator is built at Peking University. Protons exceeding IOMeV are accelerated from micrometer-thick aluminum targets irradiated by tightly focused laser pulse with 1.8 J energ...A prototype of a laser driven proton accelerator is built at Peking University. Protons exceeding IOMeV are accelerated from micrometer-thick aluminum targets irradiated by tightly focused laser pulse with 1.8 J energy and 30fs duration. The beam energy spectrum and charge distribution are measured by a Thomson parabola spectrometer and radiochromic fihn stacks. The sensitivity of proton cut-off energy to the focusing of the laser beam, the pulse duration, and the foil thickness are systematically investigated in the experiments. Stable proton beams have been produced with an optimized parameter set, providing a cornerstone for the future applications of laser accelerated protons.展开更多
本文主要完成了基于LPC2148的激光酒精检测系统的信号发生电路设计。在设计中使用LPC2148主控芯片对的AD9854 DDS(direct digital frequency synthesis,直接数字频率合成)芯片进行控制,以产生所需要的正弦信号。先进的DDS技术的应用使得...本文主要完成了基于LPC2148的激光酒精检测系统的信号发生电路设计。在设计中使用LPC2148主控芯片对的AD9854 DDS(direct digital frequency synthesis,直接数字频率合成)芯片进行控制,以产生所需要的正弦信号。先进的DDS技术的应用使得AD9854芯片可以产生高度稳定的频率、振幅可编程的正弦和余弦输出。采用93C56B存储芯片使用户可以对设定的参数进行便捷地存储和读取。同时使用3.2英寸的触摸屏作为人机交互界面,为参数设定、存取以及正弦信号的使能与禁止提供友好的操控界面,提高了系统的易用性。本文主要介绍了相关硬件及软件系统的设计,实际电路测试表明该系统稳定可靠,使用简便可以很好地满足酒精检测系统对于信号发生电路的需求。展开更多
基金Supported by the National Basic Research Program of China under Grant No 2013CBA01502the National Natural Science Foundation of China under Grant Nos 11475010,11575011 and 11535001the National Grand Instrument Project under Grant No 2012YQ030142
文摘A prototype of a laser driven proton accelerator is built at Peking University. Protons exceeding IOMeV are accelerated from micrometer-thick aluminum targets irradiated by tightly focused laser pulse with 1.8 J energy and 30fs duration. The beam energy spectrum and charge distribution are measured by a Thomson parabola spectrometer and radiochromic fihn stacks. The sensitivity of proton cut-off energy to the focusing of the laser beam, the pulse duration, and the foil thickness are systematically investigated in the experiments. Stable proton beams have been produced with an optimized parameter set, providing a cornerstone for the future applications of laser accelerated protons.
文摘本文主要完成了基于LPC2148的激光酒精检测系统的信号发生电路设计。在设计中使用LPC2148主控芯片对的AD9854 DDS(direct digital frequency synthesis,直接数字频率合成)芯片进行控制,以产生所需要的正弦信号。先进的DDS技术的应用使得AD9854芯片可以产生高度稳定的频率、振幅可编程的正弦和余弦输出。采用93C56B存储芯片使用户可以对设定的参数进行便捷地存储和读取。同时使用3.2英寸的触摸屏作为人机交互界面,为参数设定、存取以及正弦信号的使能与禁止提供友好的操控界面,提高了系统的易用性。本文主要介绍了相关硬件及软件系统的设计,实际电路测试表明该系统稳定可靠,使用简便可以很好地满足酒精检测系统对于信号发生电路的需求。
