as-500/hw13/text

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Homework 13, due Oct 10
1) Use the simple form of the NIST transition probabilities for H I. What is the transition probability for Lyman alpha? Lyman gamma?
Just reading Aₖᵢ values from the table.
6.27×10⁸ s⁻¹
1.278×10⁷ s⁻¹
2) What is the transition probability for Balmer alpha? Balmer beta?
4.410×10⁷ s⁻¹
8.419×10⁶ s⁻¹
3) What is the lifetime for the n=2 and n=4 levels of hydrogen?
This is the inverse of the sum ∑ₗAᵤ﹐ₗ where l = {1..u}.
n=2:
Lifetime T = (∑ₗA₂﹐ₗ)⁻¹
= (6.27×10⁸ s⁻¹)⁻¹
= 1.60×10⁻⁹ s.
n=4:
T = (∑ₗA₄﹐ₗ)⁻¹
= (1.278×10⁷ s⁻¹ + 8.419×10⁶ s⁻¹ + 8.986×10⁶ s⁻¹)⁻¹
= 3.313×10⁻⁸ s.