Liddick S N, Grzywacz R, Mazzocchi C, Page R D, Rykaczewski K P, Batchelder J C, Bingham C R, Darby I G, Drafta G, Goodin C, Gross C J, Hamilton J H, Hecht A A, Hwang J K, Ilyushkin S, Joss D T, Korgul A, Królas W, Lagergren K, Li K, Tantawy M N, Thomson J, Winger J A
UNIRIB, Oak Ridge Associated Universities, Oak Ridge, Tennessee 37831, USA.
Phys Rev Lett. 2006 Aug 25;97(8):082501. doi: 10.1103/PhysRevLett.97.082501. Epub 2006 Aug 21.
Two new alpha emitters 109Xe and 105Te were identified through the observation of the 109Xe --> 105Te --> 101Sn alpha-decay chain. The 109Xe nuclei were produced in the fusion-evaporation reaction 54Fe(58Ni,3n)109Xe and studied using the Recoil Mass Spectrometer at the Holifield Radioactive Ion Beam Facility. Two transitions at Ealpha = 4062 +/- 7 keV and Ealpha = 3918 +/- 9 keV were interpreted as the l = 2 and l = 0 transitions from the 7/2+ ground state in 109Xe (T1/2 = 13 +/- 2 ms) to the 5/2+ ground state and a 7/2+ excited state, located at 150 +/- 13 keV in 105Te. The observation of the subsequent decay of 105Te marks the discovery of the lightest known alpha-decaying nucleus. The measured transition energy Ealpha = 4703 +/- 5 keV and half-life T1/2 = 620 +/- 70 ns were used to determine the reduced alpha-decay width delta2. The ratio delta105Te(2)/delta213Po(2) of approximately 3 indicates a superallowed character of the alpha emission from 105Te.
通过观察109Xe→105Te→101Snα衰变链，鉴定出两种新的α发射体109Xe和105Te。109Xe核是在聚变蒸发反应54Fe(58Ni,3n)109Xe中产生的，并在霍利菲尔德放射性离子束设施中使用反冲质谱仪进行了研究。在Eα = 4062±7 keV和Eα = 3918±9 keV处的两个跃迁被解释为从109Xe（T1/2 = 13±2 ms）的7/2+基态到5/2+基态以及位于105Te中150±13 keV处的7/2+激发态的l = 2和l = 0跃迁。对105Te后续衰变的观察标志着发现了已知最轻的α衰变核。测量的跃迁能量Eα = 4703±5 keV和半衰期T1/2 = 620±70 ns被用于确定约化α衰变宽度δ2。105Te的δ(2)/213Po的δ(2)比值约为3，表明105Te的α发射具有超允许特性。
