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研究弛豫对光磁共振信号的影响

时间:2018-04-10 21:43来源:毕业论文
粒子数偏极化程度改变不了原子内部的塞曼能级大小,在稳恒磁场中,塞曼能级是固定的,因此发生光磁共振所要施加的射频磁场大小也是固定的,因此驰豫过程不会影响铷原子的g因子

摘要本次实验主要研究弛豫过程对光抽运信号、光磁共振信号以及g因子测量的影响,本文首先介绍了磁共振及其测量方法,接着引出国内外在光磁共振方面的一些研究,找出优缺点,发现实验点,明确此次实验研究意义。在第二章中重点介绍此次实验所涉及的实验仪器和实验的一些基本原理,最后分析实验结果,通过实验发现弛豫过程中,光抽运信号在驰豫趋于饱和的过程中不断增强,并且通过示波器定量测量了光抽运信号强度在弛豫过程的随时间的变化过程。加入射频磁场,光磁共振信号在驰豫增强的过程中也同样增强,追踪信号强度随时间的演化,发现光磁共振信号比光抽运信号容易达到最大值。固定扫场,改变水平场方法,测得不同驰豫条件下的g因子,发现g因子的大小并不随着弛豫过程改变。深入分析我们发现在光磁共振实验中,增强驰豫过程有利于保持粒子数分布的偏极化程度,观察到更加明显的光抽运信号。同样粒子数平衡分布有助于增加塞曼能级之间的跃迁,增强光磁共振信号。但是粒子数偏极化程度改变不了原子内部的塞曼能级大小,在稳恒磁场中,塞曼能级是固定的,因此发生光磁共振所要施加的射频磁场大小也是固定的,因此驰豫过程不会影响铷原子的g因子的测量。20895
关键词  光磁共振 弛豫过程 光抽运  g因子
毕业论文设计说明书(论文)外文摘要
Title    Effect of magnetic resonance relaxation optical signal
Abstract
The influence of the relaxation process on the optical pumping signals,opto-magnetic resonance and g factor is investigated . The magnetic resonance and the method of measuring it are introduced. The studies on the optical-magnetic resonance at home and abroad can be referenced to, finding the advantages and disadvantages ,discovering the key of the experiments ,being sure to the importance of this experiment .The experimental apparatus and some basic principle are presented in chapter 2. Finally analysis the results of the experiment .It is shown that during the relaxation process , the optical pumping signals increases continuously when the relaxation tend to saturation. The oscilloscope quantitative measure the strength of the optical pumping signals changing with time during the relaxation process.Magnetic resonance signal light rises with the increasing of the relaxation process when entering RF magnetic field ,tracking the evolution of the signal intensity changes with time,finding out magnetic resonance signal light is much easier to reach the maximum than the optical pumping signals.Fixing the sweep field and changing the level field obtains g factor under different relaxation conditions. It is shown g factor doesn’t vary with the relaxation process .In the opto-magnetic resonance experiment ,enhancing the relaxation process makes for keeping the particle number distribution of the degree of polarization ,observing more apparent optical pumping signals.While the balance distribution of paticle numbers contributes to add zeeman energy level transition and increase he opto-magnetic resonance signals.However,the degree of polarization of particle numbers can’t change the value of zeeman energy level in interior atoms.In the steady-state magnetic field,the zeeman energy is steady,as a result,the opto-magnetic resonance needs the RF magnetic field that is fixed ,finally the relaxation process isn’t influent the measurement of g factor of rubidium atoms .
Keywords  Optical resonance  Optical pumping  Relaxation process  g factor
目   次
 1  引言    1
1.1  磁共振    1
1.2  磁共振测量方法    1
1.3  国内外研究背景    2
1.4  实验研究意义    7 研究弛豫对光磁共振信号的影响:http://www.751com.cn/wuli/lunwen_12848.html
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