the practice of separating a signal by frequency (or sometimes energy or momentum) and analyzing the resulting spectrum.

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48 views

Unknown peaks on RBS spectrum

I was given a sample, that it is supposed to be a medium thickness Rhodium on top of an infinite silicon waffer. The experimental RBS spectrum along with the simulation looks like that Apparently, ...
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1answer
50 views

Wigner Threshold law in Photodetachment and Photoionization

I am writing this question here because I have a problem in understanding the Wigner Threshold law in Photodetachment and Photoionization. The Wigner Threshold Law is given by: $\sigma$=$E^{L+1/2}$. ...
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1answer
34 views

What will be the effect of placing a light source very close to a photodiode?

What will be the effect of placing a photodiode really close to a laser source and what should be the appropriate distance between a light source and photodiode to get maximum output current?
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72 views

Resolution in a Fourier transform spectroscopy setup

I am a bachelor physics student and as an assignment we had to perform measurements on an FT spectroscopy setup. Context. Our setup consisted of a Michelson interferometer through which the light ...
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1answer
123 views

Why is an exciton only observed when we excite to the conduction band and not to other electronic level inside the bandgap?

Excitons can be observed when we excite electrons to the conduction band. I don't know about excitons being observed when we excite the electrons to an electronic level that would eventually be in ...
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373 views

What is the secondary electron cutoff in ultraviolet photoelectron spectroscopy?

While the fasted emitted electrons comes from the fermi level of the material in UPS measurement, where does the slowest, which is called secondary electron cut-off orginate from? I really can't ...
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90 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 ...
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220 views

What is electron momentum density in solids and molecules?

Can someone kindly help me to know how can i get electron momentum density for one orbital like home? what is the theory of electron momentum density? how can I derive electron momentum density from ...
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60 views

Interchange symmetry for states with identical particles

I was reading this web page about interchange symmetry for states with identical particles here: http://quantummechanics.ucsd.edu/ph130a/130_notes/node317.html The article states that the highest ...
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111 views

Is there a difference between “two photon absorption” and “double quantum transitions”?

Wikipedia has articles on two photon absorption. And a lot of NMR literature refers to double quantum transitions. But is there a difference? As far as I can tell, a double quantum transition is has ...
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31 views

Quantum description of Raman effect

In the classical description of Raman effect the object of study is the electric polarizability of the system. Since I'm interested in learning the quantum description of the Raman effect and in ...
3
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0answers
48 views

SHS Interferometer and diffraction limit

I'm currently researching Spatial Heterodyned Spectrometers (SHS) and I'm a bit at a loss understanding the influence of the diffraction limit. I'll be measuring a diffuse visible light source with ...
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102 views

Line-shape asymmetry in undergraduate Hydrogen-Deuterium experiment

I'm working as an LA (undergraduate TA) for an undergraduate physics laboratory experiment where students test the Bohr model and use reduced mass to determine the approximate mass of the neutron. In ...
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49 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 ...
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7 views

Dielectric resonance spectroscopy of thin and thick film

How does the technique vary for dielectric resonance spectroscopy for thin film of ~ 3 micrometer and a relatively thick film of 100 micrometer?
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45 views

Autocorrelation function for deterministic nonlinear dynamical systems

I am quite puzzled with the problem that spectral analysis has been either applied to noisy dynamical systems or to chaotic ones. I was wondering why nobody makes analysis of non-linear dynamical ...
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50 views

Why does inelastic X-ray scattering probe the longitudinal dielectric function as opposed to the transverse dielectric function?

Light is a transverse wave. Therefore, light in the optical range (i.e. visible light) couples to transverse collective excitations of a material when measuring the optical conductivity for instance. ...
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8 views

Spatial Resolution in Magnetocardiography

In the science paper called Development of an optical cardio-magnetometer by George Bison, it is mentioned that spatial resolution of 10-20mm is required for mapping MCG signal(page 52). What does the ...
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115 views

Intensive radiative heat transfer in very hot gas ( >5000K, gas core nuclear reactor related )

The question: At temperatures above ~5000K are not stable any solid or liquid materials or even more complex molecules (such as fullerenes and Polycyclic aromatic hydrocarbons) which emit/absorb ...
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107 views

Total angular momentum in multielectron atoms

I have some confusion about orbitals in multielectron atoms. Let's say we consider an atom (Lithium, for example, $1s^2\, 2p^1$) and that the state of the last electron is [n=2, l=1, ml=0, s=1/2, ...
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61 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. ...
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0answers
84 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 ...
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125 views

Linewidth pressure broadening due to organic molecules

In relation to atmospheric spectroscopy and some other gaseous spectroscopy applications where organic molecules are present in the vapor, does anyone know of any papers or resources on pressure ...
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6 views

What is the difference between Linear and Non-Linear Magneto-optical effects?

Principle difference between Linear and Non-Linear Magneto-optical effects and how they affect the property of light passing through a Vapor medium.
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15 views

Why photoelectron imaging is a 'complete' measurement?

In many articles and books, it says that photoelectron imaging gives a 'complete' information. What is mean by 'complete' measurement or a 'complete' information? Through photoelectron imaging ...
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12 views

Interpretation of decay associated difference spetrum

We measured transient absorption spectra and we got $\Delta A(\lambda,t)=A(\lambda,t)-A(\lambda,0)$. If we use DAS (decay associated spectra) for interpretation, we assume that our data have this ...
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12 views

Dipole and multipole bound state anions: Do these bound electrons behave exactly like conventional electrons in the molecular orbitals?

Recently, I read about dipole and multipole bound anions. Dipole bound anions are those, if I understood correctly, when an electron is attached electrostatically on a neutral molecule which is polar. ...
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38 views

On characteristic X-ray spectra and relative intensity

I am looking at the following image (from http://www.schoolphysics.co.uk/age16-19/Atomic%20physics/X%20rays/text/X_ray_spectra/index.html): and I want to know, of the two curves, which one ...
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56 views

Saddle point and transition state of a molecule

During a transition of a molecule from one state to another, it pass through a transition state. This transition state, mathematically speaking, is a saddle point. That means, the second derivative ...
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27 views

What is the perceived color of a D-illuminant?

I am implementing a software that simulates the color of the sky. To do this, I use a model that takes as input the sun position and returns the Yxy components of a D-illuminant for each point of the ...
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28 views

Textbook on Diffusion and Diffusion NMR Spectroscopy

I am looking for textbooks ( Mathematical / Theoretical Physics ) that cover diffusion in general. Although it is not necessary that your recommendation covers it, I am also particularly interested ...
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36 views

Difficult to visualize Franck-Condon overlap

The franc condon principle says about the vertical transitions, means the coordinates of the nuclei remains unchanged during an electronic transition. But, what is the physical meaning or how to ...
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30 views

Doppler broadening: time scale to frequency scale

Consider a cell containing Rubidium and enlight it with a laser. Connect the system with an oscilloscope and give a triangular wave as input (so you can know when the Rubidium is resonant). This is ...
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54 views

Spectroscopy: clarification about doppler shift

I've just begun to study spectroscopy, and I need a clarification about the Doppler Effect. Considering this graph: could you explain me how I can see the doppler shift related to the deeper peak ...
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67 views

How to measure distances to stars by means of spectroscopic parallaxes?

How to measure distances to stars by means of spectroscopic parallaxes on practice? What is the accuracy of measuring distances using this method compared with distances based on HIPPARCOS ...
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55 views

Elemental sensitivity factors for Auger electrons

Is there any open database of elemental sensitivity factors for Auger electrons? I'm trying to figure out graphite oxidation degree from AES spectra, so relative sensitivity of O to C is required. ...
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101 views

Looking for raw interferogram data / raw FID data from FT-IR / FT-NIR / FT-NMR

I'm trying to get my hands on some raw interferogram data / raw FID data from an FT-IR / FT-NIR / FT-NMR so I can run some tests using FFT with it (it needs to be real data). Here's a picture below of ...
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40 views

$a^3B_2$, $b^3A_2$ and $A^1A_2$ states in electron spectroscopy

I am new to electron spectroscopy. I have a basic question regarding the molecular transition. I have learned about the states $\Sigma_g^+$ $\Pi_g$.. etc electronic states. But I could never find in ...