•For example, given a sample of 1H
nuclei in an external magnetic field of 1.41 Tesla
•ratio of populations = e((-2.67519x10e8
rad.s-1.T-1 * 1.41T * 6.626176x10-34 J.s) / (1.380662x10e-23 J.K-1 *K
293)) = 0.9999382
•At room temperature, the ratio of the
upper to lower energy populations is 0.9999382. In other words, the upper and lower
energy spin states are almost equally populated with only a very small
excess in the lower energy state.
•If N0= 106 or 1,000,000 then Nj 999,938
•N0- Nj =1,000,000 – 999,938 = 62
•62 ppm excess in the ground state