Questions tagged [atomic-physics]

Atomic physics is the field of physics that studies atoms as an isolated system of electrons and an atomic nucleus. It is primarily concerned with the arrangement of electrons around the nucleus and the processes by which these arrangements change. This includes ions as well as neutral atoms and, unless otherwise stated, for the purposes of this discussion it should be assumed that the term atom includes ions.

Filter by
Sorted by
Tagged with
0
votes
0answers
12 views

How does increasing the binding energy per nucleon release energy [duplicate]

I don’t get it. if let’s say Uranium undergoes fission to produce Barium and Krypton. Barium and Krypton will have a greater binding energy per nucleon meaning they require more energy to hold the ...
0
votes
0answers
26 views

Can we fully ionize an atom by annhilating its electrons with a positron beam?

I am unable to digest research papers on this topic so I am asking here. Can an atom be fully ionized by a positron beam through positron-electron annhilation? What are the limitations of this process ...
1
vote
0answers
23 views

Second quantization for atomic or molecular models

I'm trying to learn QED in the context of quantum chemistry (ie to model relativistic effects for heavy atoms) and I'm struggling conceptually with second quantization: specifically, what is the ...
2
votes
1answer
56 views

Hydrogen Transitions in Foot

I was reading through Foot's Atomic Physics, and saw this depiction of the transitions of the hydrogen atom. My understanding is that here we must require $\ell - \ell' = \pm 1$. Indeed, this is what ...
0
votes
0answers
4 views

Two questions on assumptions relating to a spectroscopy experiment with moving ions

In expermental trials reported in 2014 by B. Botermann et al. (atom-ph:1409.7951) selected groups of ${}^7{\rm Li}^+$ ions were moving with speeds in a narrow range close to the nominal rounded value ...
1
vote
3answers
36 views

What is the exponential (or geometric) rule (or law) for uranium enrichment?

Uranium ore starts at about .72% U-235... At ~20% U-235, it is considered to be about '90% of the way' to weapons-grade uranium, which is about ~90% U-235... Because uranium enrichment in centrifuges ...
1
vote
1answer
45 views

Conservation of isospin

Our particles course has two contradicting descriptions of how isospin must be conserved in strong interactions (assuming a perfect sitution with only the strong interaction so isospin symmetry is ...
1
vote
0answers
45 views

Confused about spontaneous emission

I thought that in spontaneous emission (say for an atom with 2 energy levels) we have the electron in the excited state and then it decays to the ground state emitting a photon at the resonance ...
1
vote
1answer
32 views

What is the spin-orbit force?

I am trying to brush up on my physics knowledge, and I have run across a term used to justify some results in a few texts that I don't recognize, the spin-orbit force $\vec s \cdot \vec l$. Quickly ...
3
votes
1answer
56 views

Is Rutherford scattering formula inconsistent with reality?

On our way to deriving the famous Rutherford scattering formula, we get a formula for the fraction ($f$) of incident alpha particles scattered by $\theta$ or more and this formula has the form $$f=\pi ...
0
votes
0answers
25 views

Why does $n \lambda = 2 \pi r$ cause a standing wave in a circle? [duplicate]

Repeat of this question since I did not find the answer satisfying as I do not see how the wave would destructively interfere with itself if the circumference is not an integer multiple of the ...
1
vote
1answer
27 views

Derivation of the radial Hartree-Fock equations

Can anyone help deriving the radial Hartree-Fock equations of atoms from the Hartree-Fock equations $$(h_i + J_i - K_i) \psi_i = E_i \psi_i$$ where each orbital $\psi_i$ involves three space ...
0
votes
0answers
10 views

How are collisions included in the optical Bloch equations?

I'm looking for a simple way of including the effect of collisions in the semi-classical optical Bloch equations. For example, spontaneous emission is included by adding a damping term with rate $\...
0
votes
0answers
17 views

What are the possible orbital occupation for a triplet state?

I am trying to run some Hartree fock calculation for interaction between an atom and a molecule. The molecule is in its triplet state and i have to indicate the orbitals that these unpaired electrons ...
0
votes
1answer
15 views

Ionization energy meaning in terms of Bohr model

Ionization energy means the energy required to remove an electron from the valence shell of an atom. Now Bohr did believe in orbits, so what does ionization energy mean in the Bohr model? I understand ...
0
votes
0answers
16 views

Finding the lowest ground state of $\rm Ne$ spin-3/2 [closed]

enter image description here The hypothetical configuration is $(1s)^4(2s)^4(2p)^2$. However, I do not understand why $p=1$ is antisymmetric in this case. The solution I have uses the 1x1 C-G ...
0
votes
0answers
19 views

The interaction of an ion with all ions in KCL crystal structure deducing its relationship as $𝑈_𝑖 = −|𝛼| 𝑒 ^2 /𝑅 + 𝛽 𝐵_𝑛 / 𝑅^𝑛$

please, if someone can answer this question? deduce the relationship of the interaction of an ion with all ions in KCL crystal structure as $𝑈_𝑖 = −|𝛼| \frac{𝑒^2}{𝑅} + 𝛽 \frac{𝐵_𝑛}{𝑅^𝑛}$
-2
votes
1answer
35 views

How does an atom for non-metals look like?

Here, I have drawn a orbit. Now, what I have studied in this atomic structure for non metals is that electron are present in orbitals. So, I have drawn them with yellow colour. Also, they (Online and ...
0
votes
1answer
56 views

What does the notation $^1 S_0$ represent in particle physics?

I'm coming across the notation $^1 S_0$, $^3 P_1$, $^1D_2$ etc. in relation to particle states. What do the two numbers and the letter represent? I've tried googling to no avail and it just appears in ...
1
vote
0answers
18 views

Calculating frequency shift due to atomic recoil momentum [closed]

The question: An atom of hydrogen emits a photon of energy $2eV = hf_0$. As a result, the H atom recoils causing the frequency of the photon to be changed to $f$. Write an expression for the change in ...
1
vote
1answer
47 views

Bohr's model of atom

In our textbook, under developments that lead to Bohr's atomic model, it is stated Dual nature of electromagnetic radiation. atomic spectra which could be explained only by assuming quantized ...
0
votes
4answers
89 views

Bohr's quantization of angular momentum

I cannot seem to find a derivation for $L=\frac{nh}{2\pi}$ I do not understand what led Bohr to quantize angular momentum in units of Planck's constant and how he was sure it works. I understand that ...
5
votes
4answers
144 views

How to explain smooth absorption spectrum of nature (plants, etc.) while the atoms have discrete absorption lines?

From quantum mechanics, a photon of energy exactly equal $h\nu=E_2-E_1$ could be captured by an atom that has the energetic level levels $E_1$ and $E_2$ (with $E_1<E_2$). This corresponds to "...
2
votes
1answer
87 views

Why was the AC Stark effect only discovered after the laser was invented?

I was reading a paper about the theory of the AC Stark effect, and I was struck by the following assertion: For instance, the first observation of the AC Stark effect initiated by the laser radiation ...
1
vote
1answer
85 views

Wavepacket for hydrogen atom?

We normally observe classical behaviour due to the time dependent schrodinger equation in simple quantum systems when we introduce 'Gaussian wavepackets' which have bell shaped uncertainty in energy, ...
0
votes
2answers
49 views

Is heat kinetic energy or changes in electron energy levels? or both?

Both sort of make sense, but some sources say that it's vibrations while others say it's electron level change.
1
vote
0answers
16 views

Hydrogen gas tube in hydrogen spectrum experiment

Generally to detect the hydrogen spectrum people uses the hydrogen gas tube as a light source. Initially the gas is formed by molecular $H_2$ and since in the experiment we detect the atomic hydrogen ...
2
votes
0answers
58 views

How is the collapse of the wave function explained through electron atom scattering?

I have learned from this answer/comments that people have put much effort into understanding how scattering of electrons on atoms could explain where, for example on a screen behind a double-slit ...
0
votes
0answers
59 views

Finding lowest energy for a comparmentialized quantum spherical well

I have a model for an electron in a box that has spherical symmetry. This is a model for a real-world problem, and I'm trying to find the lowest energy for the box. The potential trapping the electron ...
2
votes
1answer
28 views

Why is only spin-orbit interaction considered in fine structure?

There are three effects in the fine structure of atoms: the spin-orbit interaction, the relativistic kinetic energy, and the Darwin term. However, for atoms heavier than hydrogen, fine structure and ...
0
votes
0answers
16 views

How is the central potential calculated in the central field approximation?

In the central field approximation for atoms, one first guesses a central potential and then solves the TISE to obtain the electron wavefunctions. The self-consistent field approach now calculates an ...
0
votes
2answers
31 views

Modified Spectroscopic Notation (Shankar)

In Shankar's Chapter on addition of angular momentum in his Principles of Quantum Mechanics (Chapter 15 of the 2nd edition), he includes the section attached after describing the basic strategy for ...
4
votes
2answers
224 views

Why are nuclides with an even number of protons and neutrons more stable? [duplicate]

I am currently learning about Radioactivity and Nuclear Physics. Why are nuclides with an even number of protons and neutrons more stable? I have read that nuclides with an even number of protons or ...
0
votes
1answer
31 views

Best resource for dynamical symmetry of hydrogenic atom and its energy levels

I am looking to learn about how one can use group theory methods to obtain the spectrum of a hydrogenic atom algebraically. I have found many such resources online, such as this paper: http://web.mit....
2
votes
1answer
33 views

What keeps dry flat pieces of sand crumbles together (even if you microwave them)?

Originally these flat pieces get created as the top layer on the beach where water pulls back (low tide), leaving the sand to dry on the Sun. The top layer dries and creates a separate layer, making ...
1
vote
0answers
23 views

Bohr Sommerfeld in the quantum well

The Bohr Sommerfeld rule is given by: $$\oint p dx = 2\pi\left(n+\frac{1}{2} \right) $$ for potentials of the form $$u_0(x)-\lambda. $$ The proof I was presented pertained to a particle moving in a 1D ...
3
votes
1answer
72 views

What is the experimental evidence for the hydrogen atom having a Coulomb potential?

It is famously impossible to deduce the shape of a drum from its spectrum, in general. In the case of the hydrogen atom, there are non-Coulomb potentials that produce the same spectral series! (See ...
0
votes
1answer
49 views

Which book should I start to know good understanding of light-matter interaction?

Please suggest to me one or two books. And also if there is anything else interesting to follow (lectures or lecture notes).
0
votes
1answer
26 views

Deuteron magnetic moment for $l=2$

Considering the Deuteron in its $l=2$ state, I dont understand why its magnetic dipole moment is composed of $3$ terms: $$ \mu_d = \mu_n + \mu_p + \mu_{orb}$$ where the first two are the intrinsic ...
1
vote
0answers
24 views

How to work in the states $|F,m_F\rangle$ in hyperfine structure?

Suppose that we have two atoms with one proton one electron each, and these electrons interact with each other. The states for the electrons are the singlet ($S=0$) and the triplet states ($S=1$). My ...
0
votes
1answer
37 views

Is the Lamb shift big or small?

The shift is about 1000 MHz. Is this a significant number by the standard of modern spectroscopy? I mean, is it fairly easy to detect this shift nowadays? It might be difficult in 1947.
1
vote
2answers
36 views

If greater the binding energy per nucleon, more the stability, then why is Uranium (7.7MeV/nucleon) unstable?

My book says that if the binding energy per nucleon is high, then the nucleus is stable, which is why Fe (iron), with 8.8 MeV, is most stable. Why then is Uranium unstable and subject to nuclear decay?...
0
votes
0answers
17 views

Spectral lines under Zeeman splitting for sodium

For Zeeman splitting in sodium how many spectral lines are possible between $2P_{1/2}$ and $2D_{3/2}$? The selection rule says that change in $M_{J}$ should be $0, +1 \text{ or} -1$.
0
votes
0answers
36 views

On orbiting electrons losing energy in radiation

I know questions about this have been asked before, but I want to know something specific I haven't seen in the answers for those. Apparently, an accelerating charged particle loses energy, due to ...
2
votes
2answers
28 views

Can the Auger effect cause a second electron to be just excited instead of ionised and emitted from the atom?

From what I understand, the Auger effect is usually defined as when an electron deexcited but instead of releasing its change in binding energy as a photon, it transfers it as kinetic energy to ...
1
vote
2answers
69 views

Is it possible to travel at the speed of light? [duplicate]

I'm asking this question because atoms can definetely not travel at the speed of light. Atoms have electrons orbiting them at a speed very close to the speed of light, so, is it really possible for ...
3
votes
1answer
39 views

Balmer Continuum

I'm trying to simulate the Balmer series emission lines and am trying to compute the wavelengths. The Rydberg formula does this fine, up until the point where you're trying to model the spectrum at ...
1
vote
2answers
89 views

Why do we need large time assumption for energy conservation in electron transitions?

For electron absorption calculations (with an electric field perturbation $\Delta H = eE_0x \cos(\omega t)$) we end up with an integral like: $$c_2(t) \propto \int \rho(\omega) \left( \frac{\sin(\...
2
votes
1answer
28 views

Link between rotating wave approximation and stimulated emission and absorption?

In my lecture notes deriving the probability density of a two energy level atom we arive at the following equation: $$c_f(t) = \frac{1}{2} \Omega \left[\frac{1-e^{i(\omega + \omega_0)t}}{(\omega + \...
0
votes
0answers
26 views

Why cant we treat electron as a dipole in nucleus' magnetic field in this way in hyperfine structure?

In hyperfine structure modifications, the magnetic field due to magnetic moment of nucleus couples with the orbital angular momentum of the electron. The interaction(perturbation) term of the ...

1
2 3 4 5
45