A novel method has been established to realize the experiment of electron scattering off short-lived nuclei. The method was based on the well known ＂ion trapping＂ phenomenon in electron storage rings. In the R^D exp...A novel method has been established to realize the experiment of electron scattering off short-lived nuclei. The method was based on the well known ＂ion trapping＂ phenomenon in electron storage rings. In the R^D experiments at Kyoto University, stable nucleus, 133^Cs, was employed as the target nucleus. The luminosity of scattering experiment was nearly 1026 cm^-2s^-1 at electron beam current around 75 mA. The angular distribution of elastically scattered electrons from trapped Cs ions was measured and the result was well fitted by theoretical calculation. It was indicated that higher luminosity can be reached with larger electron beam current.展开更多
The lifetime of the first excited 2+ state in 18C was measured using an upgraded recoil shadow method to determine the electric quadrupole transition. The measured mean lifetime is 18.9±0.9(stat)±4.4(syst)ps...The lifetime of the first excited 2+ state in 18C was measured using an upgraded recoil shadow method to determine the electric quadrupole transition. The measured mean lifetime is 18.9±0.9(stat)±4.4(syst)ps,which corresponds to a B(E2; 2+1→0+gs) value of (4.3± 0.2±1.0) e2fm4,or about 1.5 Weisskopf units. The mean lifetime of the first 2+ state in 16C was remeasured to be about 18 ps,about four times shorter than the value reported previously. This discrepancy was explained by incorporating the γ-ray angular distribution measured in this work into the previous measurement. The observed transition strengths in 16,18C are hindered compared to the empirical transition strengths,indicating that the anomalous hindrance observed in 16C persists in 18C.展开更多
文摘A novel method has been established to realize the experiment of electron scattering off short-lived nuclei. The method was based on the well known ＂ion trapping＂ phenomenon in electron storage rings. In the R^D experiments at Kyoto University, stable nucleus, 133^Cs, was employed as the target nucleus. The luminosity of scattering experiment was nearly 1026 cm^-2s^-1 at electron beam current around 75 mA. The angular distribution of elastically scattered electrons from trapped Cs ions was measured and the result was well fitted by theoretical calculation. It was indicated that higher luminosity can be reached with larger electron beam current.
基金Ministry of Education, Culture,Sports,Science and Technology of Japan(15204017,20740163)
文摘The lifetime of the first excited 2+ state in 18C was measured using an upgraded recoil shadow method to determine the electric quadrupole transition. The measured mean lifetime is 18.9±0.9(stat)±4.4(syst)ps,which corresponds to a B(E2; 2+1→0+gs) value of (4.3± 0.2±1.0) e2fm4,or about 1.5 Weisskopf units. The mean lifetime of the first 2+ state in 16C was remeasured to be about 18 ps,about four times shorter than the value reported previously. This discrepancy was explained by incorporating the γ-ray angular distribution measured in this work into the previous measurement. The observed transition strengths in 16,18C are hindered compared to the empirical transition strengths,indicating that the anomalous hindrance observed in 16C persists in 18C.
