Probabality of jumping of e in K-e capture.

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Discussion Overview

The discussion centers on the probability of electron transitions during the K-electron capture process, specifically focusing on the competition between electrons in the 2s and 2p shells to fill a vacancy created in the 1s shell. The context includes theoretical considerations of atomic structure and decay processes in specific isotopes, such as Ar-37.

Discussion Character

  • Exploratory
  • Technical explanation
  • Debate/contested

Main Points Raised

  • One participant questions the probability of electrons from the 2s and 2p shells jumping to the 1s shell during K-electron capture.
  • Another participant provides the electron configuration for Ar-37 and discusses the competition between 2p and 3p electrons for the 1s vacancy, noting transition rates for hydrogen-like atoms.
  • There is a query about whether 2s or 3s electrons also attempt to fill the 1s vacancy and whether screening effects influence these transitions.
  • It is mentioned that the 2s-1s and 3s-1s transitions are forbidden, while the 2p-1s and 3p-1s transitions are partially screened by other electrons.

Areas of Agreement / Disagreement

Participants express uncertainty regarding the specific probabilities and mechanisms involved in the electron transitions, with no consensus reached on the exact dynamics of the K-electron capture process.

Contextual Notes

Participants note the influence of screening effects and the forbidden nature of certain transitions, but the discussion does not resolve the implications of these factors on the probabilities of electron jumps.

astro2cosmos
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as we know in L orbit there are two shell 2s & 2p. suppuse for an atom both shells are occupied , then what is the probabality of jumping of any electron from 2s & 2p shell to lower 1s in the process of K-electron capture process?
 
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Let's examine Ar=37 that decays only by electron capture.

The electron configuration in Ar-37 prior to decay is 1s(2) 2s(2) 2p(6) 3s(2) 3p(6) for a total of 18 electrons (where the number in parenthesis the number of electrons in each state). When a 1s electron is captured by the nucleus, electrons in both the 2p and the 3p states compete for the vacancy in the 1s state.

I don't have the exact answer, but for the single-electron hydrogen atom, the 2p-1s and 3p-1s transition rates are 6.25 x 108 and 1.64 x 108 sec-1 respectively*. implying that the 2p-1s transition is much more likely than the 3p-1s transition. Measuring the K x-ray fine structure maybe can determine the ratio.

From page 266 in Bethe and Salpeter Quantum Mechanics of One and Two Electron Atoms.

Bob S
 
Bob S said:
When a 1s electron is captured by the nucleus, electrons in both the 2p and the 3p states compete for the vacancy in the 1s state.

Bob S

ok. so does 2s or 3s also try to fill up the vacany?
during the transition from 2p & 3p screening effect is also apply?
from which i.e 2s or 2p it is readily jump to 1s?
 
astro2cosmos said:
ok. so does 2s or 3s also try to fill up the vacany?
during the transition from 2p & 3p screening effect is also apply?
from which i.e 2s or 2p it is readily jump to 1s?
The 2s-1s and 3s-1s transitions are forbidden. Both the 2p-1s and 3p-1s transitions are partially screened by other electrons.

Bob S
 

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