Hyperfine Structure of Nine Levels in Two Configurations ofV51. I. Experimental

The hyperfine structure of the $3d^{3}4s^2 {}_{}{}^4{}_{}{}^{}F_{\frac{3}{2},\frac{5}{2},\frac{7}{2},\frac{9}{2}}^{}{}_{}{}^{}$ and $3d^4\left({}_{}{}^5{}_{}{}^{}D\right)4s {}_{}{}^6{}_{}{}^{}D_{\frac{1}{2},\frac{3}{2},\frac{5}{7},\frac{7}{2},\frac{9}{2}}^{}{}_{}{}^{}$ levels in ${\mathrm{V}}^{51}$ has been studied in detail by the atomic-beam magnetic-resonance technique. Evidence of substantial $J$ mixing within each multiplet is found. This paper discusses the experiment itself; the following paper discusses the theoretical considerations, corrections to the raw data, and the final results.