Preparation of Thick Americium Targets and Synthesis of ₂₅₉Db

Abstract

A new isotope of ²⁵⁹Db has been produced via the reaction ²⁴¹Am (²²Ne, 4n) at E_lab=118 MeV, and its half-life of 0.51 ± 0.16 s and α-decay energy of 9.47 MeV were determined in this work. The americium targets with thickness ranged from 0.7 to 1.0 mg/cm₂ were prepared by molecular plating method through a single electrodeposition cycle. The reaction products were transported and collected using a helium jet technique and a rotating wheel apparatus. The α decays of both the products and their daughter nuclides were detected by a series of Si (Au) surface barrier detectors arranged ingeniously. The identification of ²⁵⁹Db was performed based on the genetic relationship between the new activity and the known ²⁵⁵Lr established by α-recoiled milking measurement. The Q_α value of ²⁵⁹Db derived from the present experiment is in good agreement with theoretical prediction.