Recent content by jonas_nilsson

  1. J

    Characteristic X-rays, intensity ratios

    Hi! What can be said about the intensity ratios of characteristic X-rays (Kalpha to Kbeta ) originating from a X-ray tube? I mean roughly and in general, not for some very specific anode material. I first thought that K-L (Kalpha) transitions would be more likely to happen than K-M:s...
  2. J

    REUs (or similiar) for europeans

    Kippis! Hello nordic friend! I really like Helsinki, I was there a few weeks ago and have good friends there. I think I will do what you suggest, yes. I feel I connect well with at least one professor, and perhaps she can give some advices aswell. By the way, we go for master right away...
  3. J

    REUs (or similiar) for europeans

    Hi! I feel I am on the road to research, and I would like to get some experience. I've been starting to look for something like the REU programs, but the problem is they are only open for US citizens. I guess it has with the funding to do. I must congratulate you US people on this forum...
  4. J

    Finding the Higgs: Identifying the Decay Processes in Muon Colliders

    Yes, of course the experimentalists can stand there empty handed. But I think that for example the LHC will be historical anyway, either since it discovered the Higgs or because it proved the theory wrong. And just the effort of building the LHC+experiments will be worth a note in the history...
  5. J

    Finding the Higgs: Identifying the Decay Processes in Muon Colliders

    Hi, I've been looking at ways to create Higgs bosons in lepton colliders, mostly muon colliders. I have a question on how one would be certain that it is actually the Higgs that has been found. The main channel that is going to be used seems to be the so-called s-channel, where \mu^+ + \mu^-...
  6. J

    Determening allowed states in atoms

    No I don't mean n=1 but rather 2S+1 = 1. I tried to hang the "1" a bit higher with tex-code, but it didn't work out perfectly I guess. To clarify: with upper case I mean the total spin/orbital angular momentum of all the electrons and with lower case spin/orbital angular momentum of an...
  7. J

    Determening allowed states in atoms

    Hello, there is one thing about atomic states I don't understand. I try to look at what states are possible for a np^2 configuration (that is, all lower shells are filled and don't contribute to the case). For example my textbook says that the ~^1 P state is not allowed because of the Pauli...
  8. J

    Is There a Correct Way to Post on Physicsforums.com?

    I think so too, and I think I usually do so (in forums and in real life). In case one doesn't I think the whole point of learning is kind of forgotten. I take that as a compliment =) And I think your intentions are wise, for my part I will do my best to follow them. Thanks for the feedback...
  9. J

    Is There a Correct Way to Post on Physicsforums.com?

    Hi, as it is being discussed today, I would like to ask about how to post correctly on physicsforums.com. I re-read the (updated?) agreement today, and I found this rule about where to post questions. I am still an undergraduate (I think, the levels seem to be different in different countries...
  10. J

    How Does a Strong Magnetic Field Affect LS-Coupling in Atoms?

    A question concerning atoms in magnetic fields: Why does the LS-coupling break down in a strong magnetic field (Paschen-Back effect)? I have until now only gotten this stated as a fact, but if anyone could give a few arguments it would be appreciated. Why aren't the individual components of...
  11. J

    Basic description of quantum beats

    Hi! I'm doing a basic course in atomic physics, and right now I'm looking at quantum beats. I've found several sources for basic descriptions, but there are some things that confuse me. I'm going to present some of the material in short here, and hope for comments that might make things more...
  12. J

    Local potential and diagonal

    Hello, in my lecture notes I have made a note that if V is a local potential, then <r|V|r'> is diagonal. Is this true, and how come? It popped up with the Lippmann-Schwinger equation, and I know it's important that V is local, but does really locality implicate diagonality? Jonas
  13. J

    Pure and not pure states, an example

    Aaaah, thanks George, now I sort of get the question I was trying to answer. Didn't make any sense to put question of type 1 in a test (which I am looking at). For case 2 I certainly get a mixed state. I did this approach: In case we measure a_1 the wave function collapses into: |\Psi_1> =...
  14. J

    Pure and not pure states, an example

    Hi there, I was looking at a problem, where the state (a pure state) of a two-particle system was given as: | \Psi> = A_{11}| a_1 b_1 > + A_{12} | a_1 b_2> + A_{21} | a_2 b_1> + A_{22} | a_2 b_2> In the system particle a can only be in the states a_1 or a_2 and particle b in b_1 or...
  15. J

    Scattering theory - phase shift - best approx.

    Hi all, we're looking at scattering theory in the QM course right now, and I've got a question concerning the approximative ways of calculating the phase shift \delta_l of the partial waves in the partial wave expansion of the scattered wave. One way (the semi-classical) to calculate it is...
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