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classes:2009:fall:phys4101.001:q_a_1009

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classes:2009:fall:phys4101.001:q_a_1009 [2009/10/12 15:37] – x500_sohnx020classes:2009:fall:phys4101.001:q_a_1009 [2009/10/22 12:21] (current) – czhang
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 I may have made some mistakes like where 2pi goes, so please carefully check if you are interested in this issue. I may have made some mistakes like where 2pi goes, so please carefully check if you are interested in this issue.
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 +=== Can 10/21 10:52am ===
 +For Yuichi, instead of saying A^2 is probability, I think it would make much more sense if we think of A^2 as incident intensity, just my personal opinion not sure if it is rigorous. Recall that the square of the amplitude of for E field is proportional to the intensity , E^2 is proportional to I, same analogy can be made here, then the probability can be interpreted as transmitted intensity versus incident intensity. <math>T=\frac{F^2}{A^2}</math>. At least, I think this might be easier to understand transmission intuitively, maybe not mathematically, one still has to work out all the math.
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 Why is k a known for a scattering problem? Why is k a known for a scattering problem?
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 +===Can 10/22 12:15pm ===
 +Since for scattering problem <math>E=\frac{h^2k^2}{2m}</math> which means <math>k=\frac{\sqrt{2mE}}{h}</math>, and E is the incident energy of the particle, which can be manually tuned. E is known , so k is known.
  
 ====Aspirin 10/12, 2:30pm==== ====Aspirin 10/12, 2:30pm====
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 I'm not quite sure I understood that correctly, but if I say, when a particle moves from the left to the right direction, it will transmitt through the Delta function well. In other words, there is no physical values from the right to the left direction. If we think of the opposite situation, a particle moves from the right to the left, in the first region, <math> \psi_I = Ae^{ikx} + Be^{-ikx} </math>, A would be removed because nothing can go back to the right direction. I'm not quite sure I understood that correctly, but if I say, when a particle moves from the left to the right direction, it will transmitt through the Delta function well. In other words, there is no physical values from the right to the left direction. If we think of the opposite situation, a particle moves from the right to the left, in the first region, <math> \psi_I = Ae^{ikx} + Be^{-ikx} </math>, A would be removed because nothing can go back to the right direction.
  
 +====Blackbox 10/12, 6:00pm====
 +I might write wrong in my note though. On last Wednesday, Yuichi mentioned the unit of α is Energy/length. Isn't it Energy*length? 
  
 ====Links==== ====Links====
classes/2009/fall/phys4101.001/q_a_1009.1255379842.txt.gz · Last modified: 2009/10/12 15:37 by x500_sohnx020

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