Hyperfine structure of atomic hydrogen

The author became interested in the models of confinement of the hydrogen atom inside finite volumes [2,14,17,18] in connection with the measurements of the hyperfine structure of atomic hydrogen trapped in a-quartz [19,20]. Ten years later, he extended his interests to confinement in semi-infinite spaces limited by a paraboloid [21], a hyperboloid [9] and a cone [22] in connection with the exoelectron emission by compressed rocks [23,24], Jaskolski s report [1] cited several of the above-mentioned works [9,14,17, 18,21], each one of which had formulated and constructed exact solutions for new types of confinement for the hydrogen atom. This subsection is focussed on his citation of our article [9] ... 

The hydrogen maser. The hyperfine structure of atomic hydrogen is shown as a function of the external magnetic field strength in Fig.18.16. When we study this diagram and recall our discussion of the emission and absorption of radiation in Chai tcr 9, it becomes apparent that... 

Du Mond (1965) showed that this value o a differed significantly from that derived from measurements of the Lamb shift and fine structure in hydrogen. However, subsequent improvements in these fine-structure measurements have confirmed the value of a given in equation (18.47) and the theoretical interpretation of the hyperfine structure of atomic hydrogen. 

The hyperfine structure of the Is and 2s levels can be obtained precisely for the hydrogen atom and its isotops3 and for the helium-3 ion. 

A major step forward in our knowledge of interstellar matter was made in 1951 with the discovery of the first interstellar spectral line in the radio range, the famous X21 cm hyperfine structure line of atomic hydrogen. Most of our present knowledge of the distribution and physical state of interstellar matter in our Galaxy is based on observations of this line. At first it looked as... 

The most important characteristic of ESR spectra is their hyperfine structure. The number, position and width of the lines in the spectra depend on the nature and on the conformation of the radical. The hyperfine structure of the spectra results from interaction of the unpaired electron with neighbouring atoms possessing resultant nuclear spin. When these are only hydrogen atoms... 

A theoretical expression of the hyperfine structure of the ground state of atomic hydrogen is given in eqn (1) below. Despite the high experimental accuracy of frequency measurement, values of the hydrogen ground state hyperfine structure are principally limited in accuracy at the ppm level by incomplete knowledge of the structure of the finitely-sized proton, represented in eqn. (1) by one term in a sum of various corrections ei [17]. 

S. B. Crampton, D. Kleppner, N.F. Ramsey Hyperfine structure of ground state atomic hydrogen. Phys. Rev. Lett. 11, 338 (1963)... 

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