217TH 221U A DECAY (0.66 US) 2015KH09 18NDS 201802
217TH H TYP=FUL$AUT=B. SINGH, R. SHEARMAN$
217TH2 H CIT=NDS 147, 382 (2018)$CUT=1-DEC-2017$
217TH c DICT$221U={+221}U
217TH c 2015Kh09: {+221}U produced as fusion residue in the fusion reaction
217TH2c {+176}Yb({+50}Ti,|a5n), E({+50}Ti)= 231-255 MeV reaction on a
217TH3c 0.45 mg/cm{+2} thick {+176}YbF{-3} target mounted on a rotating wheel
217TH4c synchronized with the pulsed beam, 5 ms on, 15 ms off. Evaporation
217TH5c residues (ER), separated by using gas-filled TransActinide Separator
217TH6c and Chemistry Apparatus (TASCA), with flight time of 0.53 |ms {I6}
217TH7c through the separator, were implanted in a double-sided silicon strip
217TH8c detector. The events due to radioactive decays of implanted residues
217TH9c were selected from the events related to beam using a multiwire
217THAc proportional counter (MWPC). Measured E|a, I|a, (ER)|a correlated
217THBc events from subsequent |a-decay chains, half-lives of parent nuclei
217THCc corresponding to the evaporation residues, and successive |a-decay
217THDc daughters, the latter identified by their known characteristics in
217THEc literature. The identification of {+221}U was made based on observed
217THFc (ER)|a|a correlated events in {+221}U -> {+217}Th -> {+213}Ra decay
217THGc chain using a fast data acquisition, combined with analog and digital
217THHc (CANDI) readout system. Deduced |a-reduced width.
217TH cA HF$r{-0}({+217}Th)=1.52 {I2}; interpolated value deduced from
217TH2cA r{-0}({+214}Th)=1.512 {I17} (deduced in {+218}U |a decay, see ENSDF
217TH3cA database, May 2009 update), and r{-0}({+218}Th)=1.529 {I15} (deduced in
217TH4cA {+222}U |a decay, see {+222}U Adopted dataset in ENSDF database,
217TH5cA Dec 2015 update).
221U P 0 (9/2+) 0.66 US 14 9890 50
221U cP J,T$From 2015Kh09
221U cP QP$From 2017Wa10 based on measured E|a=9710 {I50} (2015Kh09) and
221U 2cP assuming this |a transition as ground-state to ground-state transition
217TH N 1 AP
217TH cN BR$%|a|?100 for {+221}U |a decay
217TH L 0 (9/2+) 0.252 MS 4
217TH cL J,T$from Adopted levels.
217TH A 9710 50 100 0.95 23
217TH cA $Reduced alpha width |?0.1 from Rasmussen formalism (2015Kh09)
217TH cA HF$deduced by evaluators. This value is typical of favored |a decay
217TH2cA supporting the same J|p for parent and daughter ground states