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Doppler Shifts of Interstellar NaD lines
589.00 589.59 (nm) / = / = v/c Harry Kroto 2004
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The Discovery of the Interstellar Medium (ISM)
Harry Kroto 2004
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Harry Kroto 2004
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Hartman 1904 K Ti Fe Ca Na T (100K) Binary Diffuse cloud
Harry Kroto 2004
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Blue Shifted Red Shifted Harry Kroto 2004
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Blue Shifted Red Shifted Harry Kroto 2004
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Several clouds in the line of sight
Harry Kroto 2004
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Doppler Shifts in Interstellar lines
/ = / = v/c Harry Kroto 2004
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Absorption of Interstellar CN radicals in a Stellar Spectrum
Harry Kroto 2004
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Interstellar CN radicals
H-C≡N → H. + .C≡N hν .CN Binary Diffuse cloud Harry Kroto 2004
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ΔE Harry Kroto 2004
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ΔE n0 population of ground state Harry Kroto 2004
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ΔE n1 population of excited state n0 population of ground state
Harry Kroto 2004
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ΔE Boltzmann Equation n1 population of excited state
n0 population of ground state Harry Kroto 2004
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ΔE n1 = noe –ΔE/kT Boltzmann Equation n1 population of excited state
n0 population of ground state n1 = noe –ΔE/kT Harry Kroto 2004
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This is one of the most important equations of all
Boltzmann Equation This is one of the most important equations of all n1 = noe –ΔE/kT Harry Kroto 2004
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This is one of the most important equations of all
Boltzmann Equation This is one of the most important equations of all so remember it n1 = noe –ΔE/kT Harry Kroto 2004
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Only three lines observed R(0) R(1) P(1)
2 J’ Only three lines observed R(0) R(1) P(1) 1 R(0) 2 J” 1 Harry Kroto 2004
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Only three lines observed R(0) R(1) P(1)
2 J’ Only three lines observed R(0) R(1) P(1) The detection of R(1) and P(1) indicates T > 0 K 1 R(1) R(0) 2 J” 1 Harry Kroto 2004
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2 J’ 1 P(1) R(1) R(0) 2 J” 1 Harry Kroto 2004
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I ∞ n The intensity I of an absorption line is proportional to n - the number of molecules in the lower state Harry Kroto 2004
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Harry Kroto 2004
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R(1)/R(0) = SR(1)N1/SR(0)N0
Harry Kroto 2004
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R(1)/R(0) = SR(1)N1/SR(0)N0
SR(J) = (2J+2)/(2J+1) Harry Kroto 2004
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R(1)/R(0) = SR(1)N1/SR(0)N0 SR(J) = (2J+2)/(2J+1)
so for the R(1) and R(0) lines SR(1) = 4/ SR(0) = 2/1 Harry Kroto 2004
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R(1)/R(0) = SR(1)N1/SR(0)N0 SR(J) = (2J+2)/(2J+1)
so for the R(1) and R(0) lines SR(1) = 4/ SR(0) = 2/1 SR(1)/SR(0) = ⅔ Harry Kroto 2004
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R(1)/R(0) = SR(1)N1/SR(0)N0 SR(J) = (2J+2)/(2J+1)
so for the R(1) and R(0) lines SR(1) = 4/ SR(0) = 2/1 SR(1)/SR(0) = ⅔ R(1)/R(0) = (⅔) N1/N0 Harry Kroto 2004
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R(1)/R(0) = SR(1)N1/SR(0)N0 SR(J) = (2J+2)/(2J+1)
so for the R(1) and R(0) lines SR(1) = 4/ SR(0) = 2/1 SR(1)/SR(0) = ⅔ R(1)/R(0) = (⅔) N1/N0 = IR(1)/IR(1) Harry Kroto 2004
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(⅔)(N1/N0) = I1/I0 Harry Kroto 2004
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(⅔)(N1/N0) = I1/I0 N1/N0 = (3/2)(I1/I0) Harry Kroto 2004
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(⅔)(N1/N0) = I1/I0 N1/N0 = (3/2)(I1/I0) NJ = N0(2J+1)e – BJ(J+1)/kT
Harry Kroto 2004
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(⅔)(N1/N0) = I1/I0 N1/N0 = (3/2)(I1/I0) NJ = N0(2J+1)e – BJ(J+1)/kT
N1/N0 = 3 e –2B/kT Harry Kroto 2004
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(⅔)(N1/N0) = I1/I0 N1/N0 = (3/2)(I1/I0) NJ = N0(2J+1)e – BJ(J+1)/kT
N1/N0 = 3 e –2B/kT 2B = GHz Harry Kroto 2004
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(⅔)(N1/N0) = I1/I0 N1/N0 = (3/2)(I1/I0) NJ = N0(2J+1)e – BJ(J+1)/kT
N1/N0 = 3 e –2B/kT 2B = GHz (3/2)(29/86) = 3e-113.5/20.85T Harry Kroto 2004
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(⅔)(N1/N0) = I1/I0 N1/N0 = (3/2)(I1/I0) NJ = N0(2J+1)e – BJ(J+1)/kT
N1/N0 = 3 e –2B/kT 2B = GHz (3/2)(29/86) = 3e-113.5/20.85T I1/I0 = 2 e-113.5/20.85T Harry Kroto 2004
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Problem Determine the temperature of interstellar CN radicals by measuring the ratio of the heights of the R(1) and R(0) lines = I1/I0 I1/I0 = 2e – [F(1) - F(0)]/kT k = if F(J) in GHz For the CO molecule B = GHz Thus determine T (K) R(1) R(0) J =1 J = 0 F(J) = BJ(J+1) Harry Kroto 2004
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Harry Kroto 2004
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Problem Determine the temperature of interstellar CN radicals by measuring the ratio of the heights of the R(1) and R(0) lines = I1/I0 I1/I0 = 2e – [F(1) - F(0)]/kT k = if F(J) in GHz For the CO molecule B = GHz Thus determine T (K) R(1) R(0) J =1 J = 0 F(J) = BJ(J+1) Harry Kroto 2004
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35/105 = Harry Kroto 2004
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29/176 = = e-113.5/20.85T ln = /20.85T = /20.85T T = 113.5/(1.802 x 20.85) = 3.02 K error ca 3-4% k = cm-1 or GHz cm-1 = 30 GHz Harry Kroto 2004
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29/176 = = e-113.5/20.85T ln = /20.85T = /20.85T T = 113.5/(1.802 x 20.85) = 3.02 K error ca 3-4% k = cm-1 or GHz cm-1 = 30 GHz Harry Kroto 2004
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(⅔)(N1/N0) = 29/86 N1/N0 = (3/2)(29/86) NJ = N0(2J+1)e – BJ(J+1)/kT
N1/N0 = 3 e –2B/kT 2B = GHz (3/2)(29/86) = 3e-113.5/20.85T 29/176 = e-113.5/20.85T = 0.165 Harry Kroto 2004
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Only three lines observed R(0) R(1) P(1)
2 J’ Only three lines observed R(0) R(1) P(1) The detection of R(1) and P(1) indicates T > 0 K 1 P(1) R(1) R(0) 2 J” 1 Harry Kroto 2004
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Absorption of Interstellar CN radicals in a Stellar Spectrum
Harry Kroto 2004
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Harry Kroto 2004
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Only three lines observed R(0) R(1) P(1)
2 J’ Only three lines observed R(0) R(1) P(1) The detection of R(1) and P(1) indicates T > 0 K 1 P(1) R(1) R(0) 2 J” 1 Harry Kroto 2004
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Harry Kroto 2004
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Harry Kroto 2004
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Harry Kroto 2004
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Harry Kroto 2004
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Harry Kroto 2004
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Harry Kroto 2004
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Harry Kroto 2004
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Only three lines observed R(0) R(1) P(1)
2 J’ Only three lines observed R(0) R(1) P(1) The detection of R(1) and P(1) indicates T > 0 K 1 P(1) R(1) R(0) 2 J” 1 Harry Kroto 2004
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Only three lines observed R(0) R(1) P(1)
2 J’ Only three lines observed R(0) R(1) P(1) The detection of R(1) and P(1) indicates T > 0 K 1 P(1) R(1) R(0) 2 J” 1 Harry Kroto 2004
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Only three lines observed R(0) R(1) P(1)
2 J’ Only three lines observed R(0) R(1) P(1) The detection of R(1) and P(1) indicates T > 0 K 1 P(1) R(1) R(0) 2 J” 1 Harry Kroto 2004
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Only three lines observed R(0) R(1) P(1)
2 J’ Only three lines observed R(0) R(1) P(1) The detection of R(1) and P(1) indicates T > 0 K 1 P(1) R(1) R(0) 2 J” 1 Harry Kroto 2004
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Only three lines observed R(0) R(1) P(1)
2 J’ Only three lines observed R(0) R(1) P(1) The detection of R(1) and P(1) indicates T > 0 K 1 P(1) R(1) R(0) 2 J” 1 Harry Kroto 2004
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IR(1) /IR(0) ~ 29/86 = 0.337 [Measured in mm]
Harry Kroto 2004
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Only three lines observed R(0) R(1) P(1)
The detection of R(1) and P(1) indicates T> 0K Harry Kroto 2004
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Only three lines observed R(0) R(1) P(1)
The detection of R(1) and P(1) indicates T> 0K l Io I I I = Ioe- l I = Io (1 - l + …) Io - I = I ~ l Harry Kroto 2004
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IR(1) /IR(0) ~ R(1) /R(0)
Only three lines observed R(0) R(1) P(1) The detection of R(1) and P(1) indicates T> 0K l Io I I I = Ioe- l I = Io (1 - l + …) (Io – I)/ Io = I/ Io ~ l IR(1) /IR(0) ~ R(1) /R(0) Harry Kroto 2004
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IR(1) /IR(0) ~ R(1) /R(0)
Only three lines observed R(0) R(1) P(1) The detection of R(1) and P(1) indicates T> 0K l Io I I I = Ioe- l I = Io (1 - l + …) (Io – I)/ Io = I/ Io ~ l IR(1) /IR(0) ~ R(1) /R(0) Harry Kroto 2004
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IR(1) /IR(0) ~ R(1) /R(0)
Only three lines observed R(0) R(1) P(1) The detection of R(1) and P(1) indicates T> 0K l Io I I I = Ioe- l I = Io (1 - l + …) (Io – I)/ Io = I/ Io ~ l IR(1) /IR(0) ~ R(1) /R(0) Harry Kroto 2004
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IR(1) /IR(0) ~ R(1) /R(0)
Only three lines observed R(0) R(1) P(1) The detection of R(1) and P(1) indicates T> 0K l Io I I I = Ioe- l I = Io (1 - l + …) (Io – I)/ Io = I/ Io ~ l IR(1) /IR(0) ~ R(1) /R(0) Harry Kroto 2004
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IR(1) /IR(0) ~ R(1) /R(0) 29/86 = 0.337 [Measured in mm]
Harry Kroto 2004
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= (4/3ħc) n em2 (Nm-Nn) (o-) Nn = 0 R(1) ~ R(0)
the Hönl London formulae J+1 eJ2 SR(J) J eJ+12 SP(J) R(1) SR(1)N R(0) SR(0)N0 SR(J) = (2J+2)/(2J+1) Harry Kroto 2004
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= (4/3ħc) n em2 (Nm-Nn) (o-) Nn = 0 R(1) ~ R(0)
the Hönl London formulae J+1 eJ2 SR(J) J eJ+12 SP(J) R(1) SR(1)N R(0) SR(0)N0 SR(J) = (2J+2)/(2J+1) Harry Kroto 2004
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Two serendipitous radio discoveries
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Harry Kroto 2004
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Electronic Emission Spectrum of CN Radical in a Bunsen Burner Flame
v’= 0 C + N v”=3 2 1 r Harry Kroto 2004
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Harry Kroto 2004
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Rotational Structure J’= 5 v’ = 0 v” = 0 J”= 5 R Branch P Branch
v” = 0 J”= 5 R Branch P Branch Harry Kroto 2004
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J’+ 1 B’ (J+ 1)(J+2) R(J) P(1) B” J (J+ 1) J” R Branch If B” ~ B’
o + 2B J Harry Kroto 2004
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J’= 5 v’ = 0 v” = 0 J”= 5 R Branch P Branch Harry Kroto 2004
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Rotational Structure J’= 5 v’ = 0 v” = 0 J”= 5 R Branch P Branch R(0)
R(0) v” = 0 J”= 5 R Branch P Branch Harry Kroto 2004
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Rotational Structure J’= 5 v’ = 0 v” = 0 J”= 5 R Branch P Branch R(1)
R(1) R(0) v” = 0 J”= 5 R Branch P Branch Harry Kroto 2004
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Rotational Structure J’= 5 v’ = 0 v” = 0 J”= 5 R Branch P Branch R(2)
R(2) R(1) R(0) v” = 0 J”= 5 R Branch P Branch Harry Kroto 2004
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Rotational Structure J’= 5 v’ = 0 v” = 0 J”= 5 R Branch P Branch R(3)
R(3) R(2) R(1) R(0) v” = 0 J”= 5 R Branch P Branch Harry Kroto 2004
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Rotational Structure J’= 5 v’ = 0 v” = 0 J”= 5 R Branch P Branch R(3)
R(3) R(2) R(1) P(1) R(0) v” = 0 J”= 5 R Branch P Branch Harry Kroto 2004
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Rotational Structure J’= 5 v’ = 0 v” = 0 J”= 5 R Branch P Branch R(3)
R(3) R(2) P(2) R(1) P(1) R(0) v” = 0 J”= 5 R Branch P Branch Harry Kroto 2004
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Rotational Structure J’= 5 v’ = 0 v” = 0 J”= 5 R Branch P Branch R(3)
R(3) P(3) R(2) P(2) R(1) P(1) R(0) v” = 0 J”= 5 R Branch P Branch Harry Kroto 2004
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Rotational Structure J’= 5 v’ = 0 v” = 0 J”= 5 R Branch P Branch P(4)
P(4) R(3) P(3) R(2) P(2) R(1) P(1) R(0) v” = 0 J”= 5 R Branch P Branch Harry Kroto 2004
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Rotational Structure J’= 5 v’ = 0 v” = 0 J”= 5 Central section of the
P(4) R(3) P(3) R(2) P(2) R(1) P(1) R(0) v” = 0 J”= 5 Central section of the CN Band R Branch P Branch Harry Kroto 2004
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Harry Kroto 2004
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Electronic Emission Spectrum
3883 Å Å Å CN Violet Electronic Emission Spectrum 0-0 R(0) P(1) R Branch P Branch cm-1 25750 cm-1 Rotational Structure of the 0-0 band of CN at 3883Å observed from Comet Bennett (1970 II) Harry Kroto 2004
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Harry Kroto 2004
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Harry Kroto 2004
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= (4/3ħc) n em2 (Nm-Nn) (o-) Nn = 0 R(1) ~ R(0)
the Hönl London formulae J+1 eJ2 SR(J) J eJ+12 SP(J) R(1) SR(1)N R(0) SR(0)N0 SR(J) = (2J+2)/(2J+1) Harry Kroto 2004
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= (4/3ħc) n em2 (Nm-Nn) (o-) Nn = 0 R(1) ~ R(0)
the Hönl London formulae J+1 eJ2 SR(J) J eJ+12 SP(J) R(1) SR(1)N R(0) SR(0)N0 SR(J) = (2J+2)/(2J+1) Harry Kroto 2004
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= (4/3ħc) n em2 (Nm-Nn) (o-) Nn = 0 R(1) ~ R(0)
the Hönl London formulae J+1 eJ2 SR(J) J eJ+12 SP(J) R(1) SR(1)N R(0) SR(0)N0 SR(J) = (2J+2)/(2J+1) Harry Kroto 2004
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= (4/3ħc) n em2 (Nm-Nn) (o-) Nn = 0 R(1) ~ R(0)
the Hönl London formulae J+1 eJ2 SR(J) J eJ+12 SP(J) R(1) SR(1)N R(0) SR(0)N0 R(1)/R(0) = SR(1)N1/SR(0)N0 SR(J) = (2J+2)/(2J+1) Harry Kroto 2004
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= (4/3ħc) n em2 (Nm-Nn) (o-) Nn = 0 R(1) ~ R(0)
the Hönl London formulae J+1 eJ2 SR(J) J eJ+12 SP(J) R(1) SR(1)N R(0) SR(0)N0 R(1)/R(0) = SR(1)N1/SR(0)N0 SR(J) = (2J+2)/(2J+1) Harry Kroto 2004
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R(1)/R(0) = SR(1)N1/SR(0)N0 SR(J) = (2J+2)/(2J+1)
so for the R(1) and R(0) lines SR(1) = 4/ SR(0) = 2/1 SR(1)/SR(0) = ⅔ R(1)/R(0) = (⅔) N1/N0 = IR(1)/IR(1) = 29/86 Harry Kroto 2004
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R(1)/R(0) = SR(1)N1/SR(0)N0 SR(J) = (2J+2)/(2J+1)
so for the R(1) and R(0) lines SR(1) = 4/ SR(0) = 2/1 SR(1)/SR(0) = ⅔ R(1)/R(0) = (⅔) N1/N0 = IR(1)/IR(1) = 29/86 Harry Kroto 2004
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R(1)/R(0) = SR(1)N1/SR(0)N0 SR(J) = (2J+2)/(2J+1)
so for the R(1) and R(0) lines SR(1) = 4/ SR(0) = 2/1 SR(1)/SR(0) = ⅔ R(1)/R(0) = (⅔) N1/N0 = IR(1)/IR(1) = 29/86 Harry Kroto 2004
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R(1)/R(0) = SR(1)N1/SR(0)N0 SR(J) = (2J+2)/(2J+1)
so for the R(1) and R(0) lines SR(1) = 4/ SR(0) = 2/1 SR(1)/SR(0) = ⅔ R(1)/R(0) = (⅔) N1/N0 = IR(1)/IR(1) = 29/86 Harry Kroto 2004
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R(1)/R(0) = SR(1)N1/SR(0)N0 SR(J) = (2J+2)/(2J+1)
so for the R(1) and R(0) lines SR(1) = 4/ SR(0) = 2/1 SR(1)/SR(0) = ⅔ R(1)/R(0) = (⅔) N1/N0 = IR(1)/IR(1) = 29/86 Harry Kroto 2004
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R(1)/R(0) = SR(1)N1/SR(0)N0 SR(J) = (2J+2)/(2J+1)
so for the R(1) and R(0) lines SR(1) = 4/ SR(0) = 2/1 SR(1)/SR(0) = ⅔ R(1)/R(0) = (⅔) N1/N0 = IR(1)/IR(1) = 29/86 Harry Kroto 2004
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R(1)/R(0) = SR(1)N1/SR(0)N0 SR(J) = (2J+2)/(2J+1)
so for the R(1) and R(0) lines SR(1) = 4/ SR(0) = 2/1 SR(1)/SR(0) = ⅔ R(1)/R(0) = (⅔) N1/N0 = IR(1)/IR(1) = I(1)/I(0) Harry Kroto 2004
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(⅔)(N1/N0) = 29/86 N1/N0 = (3/2)(29/86) NJ = N0(2J+1)e – BJ(J+1)/kT
N1/N0 = 3 e –2B/kT 2B = GHz (3/2)(29/86) = 3e-113.5/20.85T 29/176 = e-113.5/20.85T = 0.165 Harry Kroto 2004
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(⅔)(N1/N0) = 29/86 N1/N0 = (3/2)(29/86) NJ = N0(2J+1)e – BJ(J+1)/kT
N1/N0 = 3 e –2B/kT 2B = GHz (3/2)(29/86) = 3e-113.5/20.85T 29/176 = e-113.5/20.85T = 0.165 Harry Kroto 2004
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(⅔)(N1/N0) = 29/86 N1/N0 = (3/2)(29/86) NJ = N0(2J+1)e – BJ(J+1)/kT
N1/N0 = 3 e –2B/kT 2B = GHz (3/2)(29/86) = 3e-113.5/20.85T 29/176 = e-113.5/20.85T = 0.165 Harry Kroto 2004
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29/176 = = e-113.5/20.85T ln = /20.85T = /20.85T T = 113.5/(1.802 x 20.85) = 3.02 K k = cm-1 or GHz cm-1 = 30 GHz Harry Kroto 2004
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29/176 = = e-113.5/20.85T ln = /20.85T = /20.85T T = 113.5/(1.802 x 20.85) = 3.02 K k = cm-1 or GHz cm-1 = 30 GHz Harry Kroto 2004
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29/176 = = e-113.5/20.85T ln = /20.85T = /20.85T T = 113.5/(1.802 x 20.85) = 3.02 K k = cm-1 or GHz cm-1 = 30 GHz Harry Kroto 2004
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29/176 = = e-113.5/20.85T ln = /20.85T = /20.85T T = 113.5/(1.802 x 20.85) = 3.02 K k = cm-1 or GHz cm-1 = 30 GHz Harry Kroto 2004
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29/176 = = e-113.5/20.85T ln = /20.85T = /20.85T T = 113.5/(1.802 x 20.85) = 3.02 K k = cm-1 or GHz cm-1 = 30 GHz Harry Kroto 2004
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29/176 = = e-113.5/20.85T ln = /20.85T = /20.85T T = 113.5/(1.802 x 20.85) = 3.02 K error ca 3-4% k = cm-1 or GHz cm-1 = 30 GHz Harry Kroto 2004
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“…restricted meaning” !
Harry Kroto 2004
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