Zyun-itiro Matumoto

NUCLEAR GROUND-STATE ENERGIES

The proton and neutron separation energies and the β-decay energies are estimated for most of the nuclei that have been dis- covered or will be discovered in near future. In this estimation four semi-empirical rules for the proton and neutron separation energies are used in addition to the available experimental data. These rules are also used to eliminate the wrong data and to correct the wrong interpretations of the experimental results. The “best” values thus obtained are tabulated. Explanations are given for some of the data which are eliminated or need large adjustments.

Decay Scheme of 5.3 h 113Ag

The level scheme of 113 Cd has been studied in the β-decay of 113 Ag with γ-ray singles, γ-γ and β- e coincidence measurements. Thirty-four γ-rays were assigned in 15 excited states of 113 Cd. Level order of the negative parity states based on the h 11/2 state is revised. Systematic trend of the level energies and B (E2) ratios of the collective negative parity states in odd Cd isotopes, 113-119 Cd, are discussed in the framework of an h 11/2 particle coupled with a weakly deformed core.

Decay Scheme of 5.3 h 113Ag and 1.2 min 113mAg

The β- and γ-radiations of 113g,m Ag have been studied by using Ge(Li), NaI(Tl) and anthracene detectors. The activities were produced by the 114 Cd(γ, p ) reaction. By various coincidences, including Ge(Li)–Ge(Li) configuration, most of the 30 γ-rays of the 5.3 h 113 Ag observed were fitted to a level scheme of 113 Cd consisting of the following 16 levels; 263.7, 298.4, 316.1, 583.9, 603.0, 681.0, 708.5, 821.0, 883.6, 936.3, 988.7, 1050.1, 1126.7, 1194.9, 1479.4 and 1665.4 keV. In the 113m Ag decay a total of 7 γ-rays were observed to populate the five levels at 298.4, 316.1, 441.9, 583.9 and 708.5 keV. The spins and parities were tentatively assigned from the transition intensities, and were compared with the results of ( d , p ) experiments.

Decay Scheme of 20 min 115Ag

The level scheme of 115 Cd has been studied in the β-decay of 115g Ag with γ-ray singles, γ-γ, β-γ and β- e coincidence measurements. The decay scheme which consists of 35 levels involving 104 γ-transitions was constructed. Collective band members based on the h 11/2 orbital were experimentally located at 181.0 (11/2 - ), 393.9 (7/2 - ), 417.2 (9/2 - ), 719.9 (5/2 - ) and 1092.1 (3/2 - ) in keV. Tentative assignments of spin-parities are also made for positive parity states.

Mesic Correction to the Beta-Decay in a Nucleus

Mesic corrections to beta decay interactions in a nucleus are investigated. It is found that the GamowTeller coupling constant should apparently become about 8% smaller by exchanging pions among nucleons. Also the mesic effect in the l-forbidden case is discussed. (auth)

The Levels of93Zr Populated in the Decay of93Y

The decay of 93 Y to the levels in 93 Zr has been investigated with the use of Ge(Li), Si(Li), NaI, plastic and anthracene detectors in singles and coincidence experiments. Gamma-ray energies and relative intensities were carefully determined. The resulting decay scheme consists of levels at 267.0, 946.1, 1425.5, 1449.8, 1469.5, 1650.4, 1827.1, 1908.8, 2183.7, 2457.7 and 2474.7 keV. Gamma-gamma directional correlation measurement has been performed for the 679.1–267.0 keV cascade; A 2 =-0.0049±0.0213 and A 4 =0.020±0.036. The K conversion coefficient was determined for the 267.0 keV transition; α k =0.022±0.004. The spin-parity of the 267.0 keV level has been determined to be 3/2+. The proposed level scheme was dompared with the prediction of current theoretical calculations.The decay of 93 Y to the levels in 93 Zr has been investigated with the use of Ge(Li), Si(Li), NaI, plastic and anthracene detectors in singles and coincidence experiments. Gamma-ray energies and relative intensities were carefully determined. The resulting decay scheme consists of levels at 267.0, 946.1, 1425.5, 1449.8, 1469.5, 1650.4, 1827.1, 1908.8, 2183.7, 2457.7 and 2474.7 keV. Gamma-gamma directional correlation measurement has been performed for the 679.1–267.0 keV cascade; A 2 =-0.0049±0.0213 and A 4 =0.020±0.036. The K conversion coefficient was determined for the 267.0 keV transition; α k =0.022±0.004. The spin-parity of the 267.0 keV level has been determined to be 3/2+. The proposed level scheme was dompared with the prediction of current theoretical calculations.

Decay Scheme of 50 sec 103Tc

The level scheme of 103 Ru has been studied in the β decay of 103 Tc with γ-ray singles and γ-γ coincidence measurements. The decay scheme which consists of 18 levels involving 53 γ transitions was constructed. The log f t values were determined based on γ-ray intensities and β feedings to the ground and first excited states. The level properties of 103 Ru are discussed.