Recent content by vrinda mukund

If we look into the UV photoabsorption cross sections of different gases, a kink in the cross section is seen at wavelength between 10-100 Angstrom. Can some one explain why this happens ?

Hai all, I need some help in understanding the calculation of total ionization cross section. As per the literatures, for a gas capable of multiple ionization, the total cross section is a charge-weighted sum of partial ionization cross sections. To be more elaborate, consider the case of...

In that case, in the example of Xenon, which i explained before, is it like, the excitation cross section for excitation to the 5p5 6s1 levels will be maximum when electrons are excited to 1P1 and 3P1 states ?

For electron-atom collisions, we can make energy Vs Cross section plots. We can plot how the cross section of a particular reaction, say excitation, changes with increasing energy of incident electron. The cross section will first increase with increase in energy and then will fall down.

@Simon Bridge Dear Sir, When two frequencies match together so that the system oscillates at larger amplitudes, we say the system is in resonance. My doubt is how it is applicable to excited levels. Are they the levels with the same value for angular momentum J ? I that case, what makes it...

Can someone please explain the significance of resonance levels that forms when electron collides with atoms. How this resonance levels are different from other levels ?

I was trying to understand electronic excitation in Xenon. Most of the research journals are denoting different excitation levels in terms of Paschen notation, which i think, is generally used to represent excited states of inert gases. Can someone please explain how to use this paschen notation...

Can somebody please explain how electron impact can cause optically forbidden transitions in atoms and molecules ?

@ jtbell That is not the way to add up the probability. Probability of a collision = probability of elastic collision + probability of inelastic collision = 0.6 + 0.4 =1 Again for inelastic collion, adding the probabilties of possible processes, total probability of inelastic collison = 0.5...

reply for previous posts @Simon Bridge "is this the distinction between randomness and determinism you are exploring or the distinction between regular probabilities and stochastic processes? " What i want to know is, how the scenario changes from determininstic to stochastic nature when we...

randomness thread contunues. Okay, then i will be more specific with my problem. A beam of (say, 1 million) monenergetic (say 1 keV) electrons are coming and colliding molecules, all of same species. The electrons can do either an elastic collison or an inelastic collision with molecules. If...

@DrDu Sir,I am studying the situation where molecules are freely and uniformly distributed; not on any crystal lattice. Could you please elaborate 'coherent multiple scattering ' ? In the condition where molecules are uniformly and freely distributed,is this coherent multiple scattering valid ...

Randomness confusion @Simon Bridge Sir, I am talking about the situation where millions of monoenergetic electrons coming and colliding with neutral molecules. We have cross section values availbale for different possible processes. Using these cross section values, we can find out the...

I have some confusion about multiple scattering. We always say that the problem of single scattering is always deterministic in nature.But while modeling the problem of multiple scattering, we take that the problem is stochastic in nature. I don't understand why. Why multiple...

Hi all I was trying to understand the Born-Bethe approximation related to cross sections for atomic and molecular collisions. All the stuffs that i got are explaining in complicated way which am not able to follow. Can anyone explain in simple terms what the theory explains? It will be of...