Measurements Of The Hypersonic, Rarefied Flow Field Of A Disk. - Page 97 |
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79
For the cold spectrum it was possible to obtain only about
9 to 11 "peaks" before the S/N ratio decreased to about
one.
The relative intensity of any spectral line is merely
the height of each of the "peaks" on a rotational spectrum.
To use this relative intensity information one can take
logarithms of the preceding equation for intensity to
obtain:
In { j} = -J' (J* + 1) 6R
MJ' + J" + 1) (X4 ) (G)V4J Tr
Then, merely plotting the logarithm of the "peak" heights
(intensities) versus J'(J* +1) should yield a straight
line with a negative slope. The rotational temperature T^
is then obtained from: e T r = —s—lope j
In the actual data reduction process, one must !||
account for the affect of nuclear spin which causes an
alternation in the intensities of the spectral lines. Thus,
the even-numbered peaks (2, 4, 6, etc.) must have their
observed intensity multiplied by two before using the above
relationship (Herzberg (11)).
i i j The factor G is itself dependent on T , so one must j
I i use an iterative technique (i.e., guess T ) in order to
establish the straight line through the spectral intensity
points. The foregoing procedure, when applied to many rotational
spectra, can be time-consuming. Accordingly, a data
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| Title | Measurements Of The Hypersonic, Rarefied Flow Field Of A Disk. - Page 97 |
| Repository email | cisadmin@lib.usc.edu |
| Full text | 79 For the cold spectrum it was possible to obtain only about 9 to 11 "peaks" before the S/N ratio decreased to about one. The relative intensity of any spectral line is merely the height of each of the "peaks" on a rotational spectrum. To use this relative intensity information one can take logarithms of the preceding equation for intensity to obtain: In { j} = -J' (J* + 1) 6R MJ' + J" + 1) (X4 ) (G)V4J Tr Then, merely plotting the logarithm of the "peak" heights (intensities) versus J'(J* +1) should yield a straight line with a negative slope. The rotational temperature T^ is then obtained from: e T r = —s—lope j In the actual data reduction process, one must !|| account for the affect of nuclear spin which causes an alternation in the intensities of the spectral lines. Thus, the even-numbered peaks (2, 4, 6, etc.) must have their observed intensity multiplied by two before using the above relationship (Herzberg (11)). i i j The factor G is itself dependent on T , so one must j I i use an iterative technique (i.e., guess T ) in order to establish the straight line through the spectral intensity points. The foregoing procedure, when applied to many rotational spectra, can be time-consuming. Accordingly, a data |
