Atomic physics Definition and 108 Threads

How much do the neutron fields (including the reflector) weaken on the reactor protection?

According to my understanding, when an electron is added into an atom, it emits energy in the form of photons because it is a form of de-excitation or relaxation. This is when electron affinity will be positive (exothermic). But there is one case where energy must be provided to an electron for...

Also, why does red taper off slope towards the end of the subsequence, but green and purple never taper off in slope (flatten out)?

I have Optical Emission Spectroscopy data on nitrogen's second positive system and first negative system. I would like to calculate the electron temperature using the line-ratio method, which is given as: $$k_b T_e = (E_2 - E_1) * ( ln( \frac{I_1 \lambda_1 g_2 A_2}{I_2 \lambda_2 g_1 A_1} )...

Is it realistic to switch from atomic theory to nuclear or high energy theory?

The binding energy per nucleon for each element has a specific pattern. It increases from hydrogen to iron and then decreases again. What is the fundamental reason why the binding energy per nucleon has this pattern? According to my investigation, the range of action of the strong force is...

At low photon energies, the probability of the photoelectric effect to occur increases, but the probability of the photoelectric effect to happen also increases when going towards most inner shells like K shell but inner shells require much more photon energies to be broken, so isn't there a...

Can you explain to me the reason why Thomson Scattering can not explain what happens when light meets an electron at low intensity, and what does that have to do with light being a wave or particle or relativistic/QM effects? https://en.wikipedia.org/wiki/Compton_scattering

IE = KZ(Em – E) where IE is the intensity of photons with energy E, Z is the atomic number of the target, Em is the maximum photon energy, and K is a constant. As pointed out earlier, the maximum possible energy that a bremsstrahlung photon can have is equal to the energy of the incident...

We know from molecular spectroscopy that incoming light on a molecule can change a molecule's rotational, vibrational and electronic energy levels. If the incoming light is, on the far-infrared and microwave region the molecule gets rotational energy.(microwave spectra) on the near-infrared...

I think Atomic physics gets into specific examples and experiments but I think I’m probably wrong. So, I have to ask, what is atomic physics and how is it different than quantum physics?

it is known that azimutal quantum number takes the values from 0 to n-1. how did they find it ?

(I need help with the 2nd part as I can answer the theory part properly). For E=4 eV we can find the wavelength of emitted photon. E= 4 eV = 6.4087e-19 J Using E= hc/λ we get λ=310 nm (approx) My doubt is that this should fall in the Balmer Series but we know that the lowest wavelength value...

Hello there, for the above question I have no issue finding the term symbols but I am a little unsure about employing Hund's rules to the electron configuration, particularly those referring to the energies based on the total angular momentum J. These state: - In a less than ##\frac12##-filled...

Hello everyone! I have two questions which had bothered me for quite some time. I am sorry if they are rather trivial. The first is about the general solution of the hydrogen atom schrödinger-equation: We learned in our quantum mechanics class that the general solution of every quantum system...

Can someone explain me conceptually how one can use trapped ions to make atomic clocks? My basic understanding of trapped ions is, we can think of an ionized atom which is controlled by electric and magnetic fields. But i am wondering how can one build an atomic clock using trapped ions.

To measure the atomic hydrogen spectrum people often uses hydrogen gas tubes as light source. Since the gas in the tube is the molecule ##H_2## , why we obtain the spectrum of atomic hydrogen? My guess is that because the voltage is so high, so that the molecules are totally dissociated. If...

I do not really know the relationship between potential energy and mass difference. Isn't the difference in mass of protons and neutrons due to their quarks? (the neutron is made of two down quarks and an up quark and the proton of two up quarks and a down quark.) Please help.

I was studying about atomic spectra of mono-electron species and in the pic it describes the ##4## series (principal, sharp, diffuse and fundamental). However I'm a little confused by the formula.Here my doubts are: Thanks for reading. [1]: [2]...

Hello, Next semester I'll be in my 3rd year of a physics degree in a UK university and I'll have a course on Atomic Physics. The recommended textbooks are: D G C Jones (1997). Atomic Physics. G K Woodgate (1983). Elementary Atomic Structure. Does anyone know if they are good? Are there better...

Two questions, where the 1st is related to previous discussion regarding thes couplings: The selection rules for LS coupling is quite clear - it's based on calculating the compatible electric dipole matrix element. However, in the case of jj coupling we end up with different selection rules...

The difference between light and very heavy atoms reflects itself in these two schemes. My question is why one scheme for the vector sum is necessarily the right & suitable sum model for one case, and the 2nd scheme suits the 2nd case ? In other words, why & how the relative magnitude of the...

Consider a multi-electron atom. (In our course we deal with alkalis mostly so that we have energy levels which are similar to the hydrogenic ones with quantum defect. I don't know if that is relevant here) Edit: l = orbital angular momentum of a single electron, L = total orbital angular...

Homework Statement We are investigating hydrogen in a plasma with the temperature 4500 ºC. Calculate the probability per atom and second for stimulated emission from 2p to 1s if the lifetime of 2p is 1.6 ns Homework Equations Planks radiation law: ##\rho (f) = \frac{8* \pi...

Homework Statement The spectrum shows the series 3p - nd, n = 4 - 7 in Na as well as the resonance line 3s - 3p, with the experimental vacuum wavelengths in Å.Calculate the quantum defect for the nd ##^2D## n = 4-7 terms. Estimate, as accurately as possible, the wavelength for 3p - 8d. The...

Homework Statement We are investigating hydrogen in a plasma with the temperature 4500 ºC. Calculate the probability per atom and second for stimulated emission from 2p to 1s if the lifetime of 2p is 1.6 ns Homework Equations ##A=\frac{1}{\Sigma \tau}## $$A_{2,1} = \frac{8*\pi *h *...

Okey so I think this question or a similar one was here recently but I can't find it so creating a new. Homework Statement The figure below shows the hyperfine structure in the transition 6s ##^2S_{1/2} - 8p ^2P_{3/2}## in 115In (I = 9/2). The measurement is made using a narrow-band tunable...

Homework Statement In He-like Carbon, C V, the excitation energy of 1s3s ##^1S## is 2851180 ##cm^-1## and for 1s4s ##^1S## it is 2988246 ##cm^-1##. Estimate the ionization energy. Compare with the value in the NIST database! Homework Equations ##E_{io}= T + E_{excitation}, ## ##T =...

Homework Statement The Ca spectrum below, recorded using a Fourier Transform Spectrometer (FTS), shows the resolved ##3d4s ^3D - 3d4p ^3D## multiplet. The wavenumbers and their relative intensities are given in the table. Identify all the lines and determine the fine structure constants in the...

Homework Statement The figure below shows the hyperfine structure in the transition 6s $^2S_{1/2}$ - 8p $^2P_{3/2}$ in 115In (I = 9/2). The measurement is made using a narrow-band tunable laser and a collimated atomic beam; hence the Doppler width is greatly reduced. The 6 components shown have...

Homework Statement The total spin of an Mg atom is zero and remains zero after absorption or emission of a photon. To which states can one of the electrons in the outer shell get by absorption of a single photon: 4s, 5s, 3p, 4p, 3d, 4d?2. The attempt at a solution I am not sure which of the...

I need to calculate the energy of the ground state of a helium athom with the variational method using the wave function: $$\psi_{Z_e}(r_1,r_2)=u_{1s,Z_e}(r1)u_{1s, Z_e}(r2)=\frac{1}{\pi}\biggr(\frac{Z_e}{a_0}\biggr)^3e^{-\frac{Z_e(r_1+r_2)}{a_0}}$$ with ##Z_e## the effective charge considered...

Homework Statement Considering the molecule of ##C_2^+## in an excited state with valence configuration ##2\sigma_g^2## ##2\sigma_u^2## ##1\pi_u^2## ##3\sigma_g^1##. Finding all the possible term symbol. Homework Equations Term symbol ##^{2S+1}\Lambda## ##L=0 \rightarrow \Sigma## ##L=1...

Radial and angular nodes are simply a region where the wavefunction is zero. But speaking about their dimensions, do they have any thickness or are they just an infinitesimal point in space without dimensions? Thanks a lot!

Homework Statement Homework EquationsThe Attempt at a Solution Hi All, My problem is that when I calculate this integral or use software to do it for me I get (3*i*pi)/16, when I've been told that the answer is 1/2i giving a probability of 1/4. Would someone be able to point out where my...

Okay, so I've been set this homework to find the normalisation constant, N, for the radial wave function in the 2s state for hydrogen (my title was too long to fit that vital information in). thing is; I'm having a bloody hard time and in the process confusing myself with trying to take out all...

Hi, I have an assignment to derive the two following expressions: R(J)-P(J)=2B'(2J+1) R(J-1)-P(J+1)=2B''(2J+1) where Bis the rotational constant and prime ' stands for upper level and bis '' for lower level. Bv=Be-α(v+1/2) using the selection rules (I guess in this case ΔJ=±1) and...

Homework Statement Earlier in the book it was remarked that early in the history of nuclear physics the electrically neutral mass of nuclei now attributed to neutrons was considered to arise from neutral particles composed of combinations of protons and electrons (as opposed to neutrons in...

Homework Statement [/B] Consider the hydrogen atom in the 42F5/2 state. Take into account the effects of finestructure (spin-orbit coupling). (a) Write down the spectroscopic notation of the state that the 42F5/2 is degenerate with, in the absence of an external magnetic field. (b) Calculate...

Question (a) Write down the quantum numbers for the states described in spectroscopic notation as 2S3/2, 3D2 and 5P3. (b) Determine if any of these states are impossible, and if so, explain why. (Please note that these could describe states with more than one electron.) My Attempt A) I came...

Hello everybody, while I tried to understand the Rubidium level scheme, I realized that I have some issues concerning the energy levels in general... If in addition to the orbital Momentum the spin momentum of an electron is considered for example the p level splits to the 2P1/2-level and the...

Why do galaxy and galaxy clusters look so colorful?

Homework Statement Consider an electron in a state described by angular wavefunction $$\psi(\theta,\phi)=\sqrt{\frac{3}{4 \pi}}\sin \theta \cos \phi$$ Here θ and φ are the polar and azimuthal angles, respectively, in the spherical coordinate system. i. Calculate the probability that a...

i´ve got a question concerning Ramsey interferometry and fringes. Consindering the case we have 2 pi/2 pulses as usual. For this case it is easy to calculate the mean value of the Bloch component w by applying a rotation matrix, say rotating around the Bloch component v. Then applying a rotation...

Homework Statement Using Hund's rules, find the ground state L, S and J of the following atoms: (a) fluorine, (b) magnesium, and (c) titanium. Homework Equations J = L + S The Attempt at a Solution I'm having trouble understanding what L, S and J mean on a basic level. I read the textbook...

Dear Everyone, Could anyone explain why we count only the number of radial nodes between the subshells that have the same orbital angular momentum l ? For example, 3p-orbitals have 1 radial node that exists between the 3p- and 2p-orbitals. Shouldn't be there additional radial nodes that exist...

In multiple-electron atoms the effective charge of nucleus for a given electron, is reduced by the presence of other electrons (including those from more external shells, against the shell theorem): Z_eff = Z - s where the screening constant s depends on Z and the concerning orbital. It is...

Can anyone explain the second rule, because the Wikipedia page is not very clear? Hund's zeroth rule - Ignore all inner shells and focus on the outermost shell. Hund's first rule - Put the electrons such that they maximize spin, ##s##. So far so good. Hund's second rule appears to be simply...

Homework Statement Homework EquationsThe Attempt at a Solution Very confused by this problem. For one thing, it doesn't specify if there is or isn't any light present to drive the stimulated emission/absorbtion. I guess there's no reason to assume that there is no light - but since the...

Hello friends. My question consists two parts, 1-What is the difference between an optical and an acoustic phonon? 1-What are the conditions by which we can decide the type of phonon i.e optical or acoustic phonon ? Hope to get the reply soon.