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We have measured, with improved precision, the energy of gamma rays from the decay of "Sc, 44m Sc, and 48 Sc and observed a previously unreported crossover in the decay of 48 Sc. These isotopes were produced by (p, n) reactions on "Ca and 48 Ca. Hydrogen ions were accelerated to 25 MeV in the NRL Sector-Focussing Cyclotron to give the equivalent of ~ 2 μ& of 12.5 MeV protons on calcium oxide or metallic calcium targets. At the proton energy used in this experiment, the (p, n) reaction is the dominant one, and no serious interference was observed from other reactions or (p, n) reactions on other isotopes. The gamma-ray spectrometer consisted of a 10 cc Ge(Li) detector and a 4096-channel analyzer. Prior to each run, the spectrometer was calibrated with gamma-ray energy standards [1] from 137 Cs, 88 Y, e0 Co, and natural thorium. The calibration was verified by recording some spectra with simultaneous exposure of the detector to external 88 Y and/or eo Co sources. The data from the 4096-channel analyzer was fed into a CDC 3800 computer and searched for peaks. The output of the computer gave the gamma-ray energy and area under the peak for all statistically significant peaks.The decay scheme for "Sc, shown in Fig. 1, is similar to that recently published by KING et al. [2], but with more precise measurements of the gamma-ray energies. Table 1. Gamma rays from the decay of "Sc and " m Sc , toto -J 'KS I?|0.

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