C2 Radical (C2)- LIF:

Electronic Transitions:

Swan bands: d 3Pg <--> a 3Pu (0,2), (0,1), (0,0), (1,0) and (2,0) bands of C2

Deslandres-d'Azambuja bands: C 1Pg --> A 1Pu  emissions of C2

Mulliken bands: D 1Su+ <--> X 1Sg+ (0,2), (0,1), (0,0), (1,0) and (2,0) bands of C2

Fox-Herzberg bands: e 3Pg --> a 3Pu emissions of C / (not detected)

Freymark bands: E 1Sg+ <--> A 1Pu (0,3), (0,2), (0,1) and (0,0) bands of C2

Appearance of the C2 transitions:

Swan bands: Degraded to the violet

Deslandres- d'Azambuja bands: Degraded to the violet

Mulliken bands: ?

Fox-Herzberg bands: Degraded to the red

Freymark bands: Degraded to the violet

Excitation wavelength ranges:  

Transitions of C2

Excitation wavelength

range [nm]

Emissions [nm]

Swan bands: d 3Pg <--> a 3Pu (0,3), (1,4), (2,5) bands

690 to 620 nm 438 nm, 473 nm, 516 nm, 563 nm, 619 nm, 685 nm

Swan bands: d 3Pg <--> a 3Pu (0,2), (1,3), (2,4) bands

620 to 563 nm 438 nm, 473 nm, 516 nm, 563 nm, 619 nm, 685 nm
Swan bands: d 3Pg <--> a 3Pu (0,1), (1,2), (2,3), (3,4) bands 563 to 518 nm 438 nm, 473 nm, 516 nm, 563 nm, 619 nm, 685 nm
Swan bands: d 3Pg <--> a 3Pu (0,0), (1,1), (2,2), (3,3) bands 518 to 474 nm 438 nm, 473 nm, 516 nm, 563 nm, 619 nm, 685 nm
Swan bands: d 3Pg <--> a 3Pu (1,0), (2,1), (3,2), (4,3) bands 474 to 438 nm 438 nm, 473 nm, 516 nm, 563 nm, 619 nm, 685 nm
Swan bands: d 3Pg <--> a 3Pu (2,0), (3,1), (4,2) bands 438 to 409 nm 438 nm, 473 nm, 516 nm, 563 nm, 619 nm, 685 nm
Swan bands: d 3Pg <--> a 3Pu emissions UV 438 nm, 473 nm, 516 nm, 563 nm, 619 nm, 685 nm
Deslandres-d'Azambuja bands: C 1Pg <--> A 1Pu (0,3), (1,4) bands 470 to 440 nm 339 nm, 360 nm, 385 nm, 410 nm, 438 nm
Deslandres-d'Azambuja bands: C 1Pg <--> A 1Pu (0,2), (1,3) bands 438 to 420 nm 339 nm, 360 nm, 385 nm, 410 nm, 438 nm
Deslandres-d'Azambuja bands: C 1Pg --> A 1Pu emissions 690 to 209 nm 339 nm, 360 nm, 385 nm, 410 nm, 438 nm
Mulliken bands: D 1Su+ <--> X 1Sg+ (0,2), (1,3), (2,4) bands 253 to 248 nm 231 nm
Mulliken bands: D 1Su+ < --> X 1Sg+ (0,1), (1,2), (2,3) bands 242 to 238 nm 231 nm, 360 nm, 385 nm, 410 nm, 438 nm, 473nm
Mulliken bands: D 1Su+ < --> X 1Sg+ (0,0), (1,1), (2,2) bands 233 to 229 nm 231 nm, 360 nm, 385 nm, 410 nm, 438 nm, 473nm
Mulliken bands: D 1Su+ < --> X 1Sg+ (1,0), (2,1), (3,2) bands 225 to 218 nm 231nm
Mulliken bands: D 1Su+ < --> X 1Sg+ (2,0), (3,1), (4,2) bands 217 to 212 nm 231nm
Freymark bands: E 1Sg+ < --> A 1Pu (0,3), (1,4), (2,5)  bands 239 to 232 nm 201 nm, 207 nm, 214 nm, 222 nm, 229 nm, 238 nm
Freymark bands: E 1Sg+ < --> A 1Pu (0,2), (1,3), (2,4)  bands 230 to 224 nm 201 nm, 207 nm, 214 nm, 222 nm, 229 nm, 238 nm
Freymark bands: E 1Sg+ < --> A 1Pu (0,1), (1,2), (2,3)  bands 222 to 216 nm 201 nm, 207 nm, 214 nm, 222 nm, 229 nm, 238 nm
Freymark bands: E 1Sg+ < --> A 1Pu (0,0), (1,1), (2,2)  bands 214 to 210 nm 201 nm, 207 nm, 214 nm, 222 nm, 229 nm, 238 nm
Fox-Herzberg bands: e 3Pg --> a ePu emissions not detected not detected

Table 1: Electronic transitions and emissions of the C2 radical.

Flames/Burners:

     1.  acetylene/oxygen (C2H2/O2) flame of a welding torch

Gratings of the Chromex 250 IS imaging spectrograph:

     1.  100 lines/mm

     2.  1200 lines/mm

Comment:  With the buttons on top of this page you can select different flames within the C2 transition bands. The tolerances of the measured values are given in the following table:

Measured Value Tolerance in [nm]
laser wavelength (excitation wavelength)  ± 0,15 nm
emission wavelength, 1200 l/mm ± 0,2 nm
emission wavelength, 100 l/mm ± 2 nm

Table 2: Measured value tolerances for the wavelengths in [nm]. Check the emission wavelength of the EES with the Rayleigh lines (UV, VIS, UV 2nd order).

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