Flashcards
Atomic Energy Level Transitions
Cards in this deck (14)
- 1Atomic Energy Level Transitionsenergy released per transition
x
number of atoms
x
likelihood of transition - 2Energy Level Populationsn(l) g(l)
--------- = -------- exp(Eu-El)/kT
n(u) g(u)
where g(u) is statistical weight - 3Collisional Excitationcollisions between particles are important in energy level transitions - not just emission/absorption
- 4Einstein CoefficientsThe likelihood that an electron will transition between an upper and lower energy state is governed by the Einstein Coefficients
- 5- Jweighed mean intensity
= integral (J*Phi df)
=integral (incident field spectrum * normalised absorption profile) - 6AulSpontaneous Emission Coefficient
transition probability/time when
electron transitions from Eu to El - 7BluAbsorption Coefficient
transition probability/time for electron transitioning from El to Eu - 8Bul * Jbartransition probability/time for stimulated emission of a photon by an electron transitioning from Eu to El in the presence of an external radiation field
- 9Relationship Between the Coefficientsnl*Blu*Jbar = nu*Aul + nu*Bul*Jbar
- 10Coefficient Relationsgl*Blu = gu*Bul
and
Bul = c^2*Aul
-------------
2hf^3 - 11Total Flux in an Emission LineFlux is proportional to
h*f0*nu*Aul - 12Emission Line RatiosF(u1,l1) (Eu1-El1)*nu1*Au1,l1
------------- = ---------------------------------
F(u2,l2) (Eu2-El2)*nu2*Au2,l2 - 13Origin of TransitionsE1 is the electric dipole term, the first term and dominant term . The higher order terms are M1 (magnetic dipole term), E2 (electric quadrupole term) etc.
- 14Forbidden TransitionsTransitions that proceed via higher order terms of the transition operator
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- Photons in Astrophysics Flashcards on Atomic Energy Level Transitions, created by k m on 04/01/2019.
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- k m
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