215U COMMENTS ENSDF 201509 215U H TYP=FUL$AUT=M. Trudel,L.A.Bernstein$CIT=ENSDF$CUT=15-Sep-2015$ 215U C TITL$NUCLEAR DATA SHEETS FOR 215U 215U c AUTH$M. Trudel, L.A. Berstein 215U c INST$Uninversity of California 215U #c Berkeley, California 94720 215U c ABST$Identification and g.s. properties of 215U based on 215U 2c {+180}W({+40}Ar,5n) (2015Ya13 are presented. 215U c CUT$All data received by 15 September 2015 have been considered. 215U c FUND$Research sponsored by Office of Science, Office of Nuclear 215U xc Physics, US Department of Energy, under contract DE-AC02-05CH11231. 215U C CIT$ENSDF 215U ADOPTED LEVELS ENSDF 201509 215U H TYP=FUL$AUT=M. Trudel,L.A.Bernstein$CIT=ENSDF$CUT=15-Sep-2015$ 215U H TYP=MOD$AUT=C. Morse$DAT=9-Jul-2024$COM=Updated Q-values 215U Q 1.86E+313 8.59E+3 6 2021Wa16 215U cQ $S(2p)=1810 {I10}, Q(|ep)=6910 {I10} (2021Wa16) 215U c All data based on {+180}W({+40}Ar,5n) (2015Ya13) 215U c 2015Ya13: first observation of {+215}U, produced in 215U 2c {+180}W({+40}Ar,5n) reaction. Experiment was performed at the gas- 215U 3c separator SHANS, and the {+40}Ar beam was delivered by the sector 215U 4c focusing cyclotron of the Heavy Ion Research Facility in Lanzhou 215U 5c (HIRFL), China. The typical beam intensities were about 150-250 215U 6c pnA. Enriched {+180}W targets (91.4% {+180}W and 8.5% {+182}W) with 215U 7c average thickness of 481 |mg/cm{+2} were evaporated on carbon foils of 215U 8c 43 |mg/cm{+2} and covered with carbon layers of 14 |mg/cm{+2}. Two 215U 9c different beam energies were run: 204.5 MeV and 207.6 MeV in order to 215U Ac assign the decay chain definitively to the 5n evaporation channel. The 215U Bc estimated beam energies at the center of the target and the relevant 215U Cc irradiation times (in parentheses) in the two runs are 202.4 MeV 215U Dc (89 hours) and 205.5 MeV (157 hours), respectively. The evaporation 215U Ec residues were implanted into three 300 |mm thick position-sensitive 215U Fc strip detectors (PSSDs), installed side by side at the focal plane of 215U Gc the separator. Each PSSD, with an active area of 50x50 mm{+2}, was 215U Hc divided into 16 vertical strips in the front face. The energy 215U Ic resolution with all strips summed was about 70 keV (FWHM) for 5-9 MeV 215U Jc |a particles and the vertical position resolution was about 2.5 mm 215U Kc (FWHM). Upstream the PSSDs, 8 non-position-sensitive Si detectors 215U Lc (side detectors) of similar type were mounted. The PSSDs and the side 215U Mc detectors formed a Si-box detector. The efficiency of the Si-box 215U Nc detector for detecting an |a particle with full energy was about 80% 215U Oc of 4|p. Measured E|a and half-life of {+215}U 215U L 0 0.7 MS +13-3 215U 2 L %A>0$ %EC+%B+=?$ 215U cL $Only the |a decay mode is reported by 2015Ya13 215U cL E$Observed activity is assumed to be associated with the {+215}U 215U 2cL ground state 215U cL T$measured by 2015Ya13, using E|a=8428.0 keV {I3} and the method 215U 2cL described by 1984Sc13 for analyzing low-statistics data. The half-life, 215U 3cL 0.73 ms {I+133-29} reported by 2015Ya13 is rounded here 215U cL $The identification of the products was performed using the method of 215U 2cL energy-position-time correlated |a-decay chains. A group of two 215U 3cL correlated chains assigned to {+215}U was observed at the lab-frame 215U 4cL energy of 205.5 MeV. Based on the two decay chains, the |a-particle 215U 5cL energy and half-life of the daughter nucleus were determined to be 215U 6cL 7780.0 keV {I3} and 20.8 ms {I+379-82}, which are consistent with 215U 7cL the |a decays from {+211}Th and {+212}Th. The observed granddaughter 215U 8cL decays are consistent with the |a decays from {+207}Ra and {+208}Ra. 215U cL $The authors state that due to the similarities in the |a decays of 215U 2cL {+215}U and {+216}U, it is not possible for them to make an 215U 3cL unambiguous identification of the two observed decay chains based on 215U 4cL decay properties alone. However, they prefer to assign the two decay 215U 5cL chains to {+215}U on the basis of two other important facts. Firstly, 215U 6cL they can be sure that these two isotopes have a mass number less than 215U 7cL 216 because they are formed at higher excitation energy in the 215U 8cL {+40}Ar+{+180}W system than that required to produce the {+216}U. 215U 9cL Secondly, the two decay chains are unlikely to be {+216}U produced in 215U AcL 6n evaporation channel from {+182}W component in the target due to the 215U BcL cross sections reported for each of the products in the 215U CcL {+182}W+{+40}Ar reaction. Cross section calculations were performed 215U DcL using the HIVAP reaction code. 215U cL $Measured production cross section for {+215}U at the beam energy of 215U 2cL 205.5 MeV was determined to be 50 pb {+70-30}, using a transmission 215U 3cL efficiency of 14% (2015Ya13).