Tagged Questions

1
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0answers
48 views

How to absorb a characteristic line in a spectrum

I have an x-ray tube. When I see the spectrum, I notice the characteristic lines of the anode. What do I have to do if I want to absorb a characteristic line? I have thought that I can add a filter. ...
0
votes
2answers
56 views

Do excited electrons drop back to same quantum state?

I'm trying to wrap my head around spectroscopy, therefore, I am looking for as complete an answer as possible here, hence why I have broken the question into a different points. Here is what I know ...
1
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1answer
31 views

Electronic, vibrational and rotational autoionization

Can anyone please explain me the concept of electronic, vibrational and rotational autoionization. What I understood is, autoionization usually occurs when the ion core is rotationally or ...
4
votes
1answer
124 views

QM with complex eigenvalues

What class of theories/physical systems own finite/infinite complex eigenvalues? I do know that e.g., quasinormal modes of BH do have complex eigenvalues, but are they finite or infinite in number? ...
1
vote
1answer
85 views

Mysterious spectra?

In my blog post Why riemannium? , I introduced the following idea. The infinite potential well in quantum mechanics, the harmonic oscillator and the Kepler (hygrogen-like) problem have energy spectra, ...
0
votes
0answers
32 views

Thermionic emission, delayed emission and predissociation

In molecular photodissociation, the thermionic emission, delayed emission and predissociation are the same? otherwise, what is the difference between them? My question is not about the solids, but I ...
1
vote
3answers
552 views

Franck Condon Principle and Born Oppenheimer approximation

My question here is purely fundamental. I am confused with the concept in Franck Condon (FC) principle and Born Oppenheimer (BO) approximation. The FC principle is in accordance with the BO ...
1
vote
1answer
59 views

Can I prove boundedness of an operator without checking it for its whole domain?

(I don't have a direct reference so this is a little fishy and I'll delete it if nobody recognises what I'm talking about, but I though for starters I'll ask anyway) I've heard at university that if ...
2
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0answers
39 views

How large would the electric field need to be to split the mj -/+1 626.6 nm line of neon?

I am an undergraduate considering an extension on a quantum beats experiment with neon. The premise is to excite neon atoms coherently from a metastable 'ground' state into a superposition of excited ...
1
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3answers
108 views

Why is the planck function continuous and not discrete?

If we imagine a object made up of Hydrogen gas that is optically thick to all radiation, and is in thermal equilibrium, then, microscopically, photons will be emitted and absorbed as ...
1
vote
0answers
45 views

Correlation function in relaxation in NMR

I am new in this community, I am from a chemistry background. I want to know a detailed solution of a density matrix for a singlet state using the concept of spin lattice relaxation in NMR. I will ...
2
votes
2answers
315 views

Energy shift between hydrogen and deuterium

Stated: The atomic spectra of hydrogen and deuterium are similar however shifted in energies. So im trying to explain why it is that the emission lines are shifted and how they are shifted. Since ...
1
vote
2answers
156 views

How the spectrum of the hydrogen atom is checked/detected experimentally?

When solving the hydrogen atom, as a 2 body problem, we have the motion of the center of mass and the motion relative to the center of mass. The well known energy spectrum, $E_n$, that goes like ...
2
votes
2answers
194 views

Why are overtones forbidden within the harmonic approximation?

In vibrational spectroscopy only transitions between neighboring vibrational states ($\Delta \nu = \pm 1$, $\nu$ being the vibrational quantum number) are allowed within the harmonic approximation. ...
5
votes
2answers
1k views

Relation between total orbital angular momentum and symmetry of the wavefunction

My question essentially revolves around multi-electron atoms and spectroscopic terms. I understand the idea that the total wavefunction for Fermions should be antisymmetric. Consider as an example, ...
2
votes
2answers
1k views

How do electron configuration microstates map to term symbols?

I am trying to understand energy levels of electron configurations. I visited the NIST web site and discovered that the notation used here are called term symbols. After reading corresponding ...
2
votes
3answers
587 views

Unstable energy levels

Well, reading about "Raman Effect" I saw that when the electron absorb some energy, with frequency $ \omega_{abs} $, that is different from $ \omega_{n} - \omega_{n-1} \neq \omega_{abs1} $, it go to ...
4
votes
1answer
591 views

Selection Rules in electron spectroscopy

How to derive the selection rules $\Delta L= \pm 1$, $\Delta S=0$ for electron spectroscopy?
2
votes
3answers
621 views

Photon absorption probability for a given molecule in gas phase

So I'm pretty sure I'm approaching this problem in the wrong way and I need some guidance (my first hint is that I think I'm thinking about a quantum mechanical problem too classically) Suppose there ...
3
votes
1answer
163 views

Is it possible to determine timescales of electron dynamics from the natural linewidth of an electronic transition?

A lot of work has been done recently on electron dynamics using attosecond pump-probe techniques; for instance in this paper. In this particular paper, the authors photoionized the neutral ...