0000000000641781
AUTHOR
Alexandra Lightfoot
Experimental study of isomeric intruder ½+ states 197,203At
A newly observed isomeric intruder ½ + state [ T ½ = 3.5 ( 6 ) ms ] is identified in 203 At using a gas-filled recoil separator and fusion-evaporation reactions. The isomer is depopulated through a cascade of E 3 and mixed M 1 / E 2 transitions to the 9 / 2 − ground state, and it is suggested to originate from the π ( s ½ ) − 1 configuration. In addition, the structures above the ½ + state in 203 At and 197 At are studied using in-beam γ -ray spectroscopy, recoil-decay tagging, and recoil-isomer decay tagging methods. The ½ + state is fed from 3 / 2 + and 5 / 2 + states, and the origin of these states are discussed. peerReviewed
Analysis of the charge state distribution produced in a 78Kr + 98Mo fusion evaporation reaction utilizing the MARA separator
Experimental results on the charge state distribution of the fusion evaporation reaction 78Kr + 98Mo are presented. The data has been taken from the 1st commissioning run of MARA (Mass Analysing Recoil Apparatus). Data from the charge states of q = 29 − 33 were collected. Here, q represents the elementary charge describing the number of electrons removed from a neutral atom. Results show an expected gaussian distribution around the most probable charge, ̄q. A most probable charge state of ̄q = (27.99 ± 0.20) was obtained after fitting the data. The value of ̄q was lower than initially anticipated, which was mainly a result of a less than desired beam energy delivered on the day of testing.