Author: Balraj Singh |  Citation: Nucl. Data Sheets 156, 70 (2019) |  Cutoff date: 31-Jan-2019 

 Full ENSDF file | Adopted Levels (PDF version) 

S(n)= 8230 keV 60S(p)= 1980 keV SYQ(α)= 11117 keV 28
Reference: 2017WA10

General Comments:

2001Ho06 (also 2002Ho11, 2011Ac01, 2015Mu16 review): 270Ds produced in 207Pb(64Ni,n),E=317 MeV using UNILAC accelerator facility and SHIP separator at GSI. Experiments performed under an international collaboration between laboratories in Germany, Slovakia, Poland, and Russia. Of the eight correlated events detected, six involved EVR-α1-α2-SF correlations, and two EVR-α2-SF. Two groups for the six α-decays assigned to 270Ds as follows: events #1, #2, and #3 belonged to the g.s., and events #4, #5, and #6 to states originating from a K-isomer (as in the case of the longest half-life in event #6) or γ-decay.

History of correlated events observed by 2001Ho06:

Event #1:

Eα1=10987 keV 90, Δt1=0.07 ms, assigned to 270Ds

Eα2=4168 keV (escaped), Δt2=0.43 ms, assigned to 266Hs

ESF=189 MeV, Δt3=11.02 ms, assigned to 262Sg (SF decay)

Event #2:

Eα1=11075 keV 90, Δt1=0.18 ms, assigned to 270Ds

Eα2=10196 keV 20, Δt2=0.87 ms, assigned to 266Hs

ESF=193 MeV, Δt3=10.26 ms, assigned to 262Sg (SF decay)

Event #3:

Eα1=1925 keV (escaped), Δt1=0.20 ms, assigned to 270Ds

Eα2=10173 keV 90, Δt2=2.79 ms, assigned to 266Hs

ESF=164 MeV, Δt3= 8.84 ms, assigned to 262Sg (SF decay)

Event #4:

Eα1=11151 keV 20, Δt1=2.00 ms, assigned to 270mDs

Eα2=10171 keV 20, Δt2=18.22 ms, assigned to 266Hs

ESF=199 MeV, Δt3=13.06 ms, assigned to 262Sg (SF decay)

Event #5:

Eα1=12147 keV 50, Δt1=10.35 ms, assigned to 270mDs

Eα2=10281 keV 90, Δt2=9.63 ms, assigned to 266Hs

ESF=215 MeV, Δt3=7.77 ms, assigned to 262Sg (SF decay)

Event #6:

Eα1=10954 keV 20, Δt1=17.71 ms, assigned to 270mDs

Eα2=10180 keV 20, Δt2=0.34 ms, assigned to 266Hs

ESF=190 MeV, Δt3=3.98 ms, assigned to 262Sg (SF decay)

Event #7:

Eα2=578 keV (escaped), Δt2=0.46 ms, assigned to 266Hs

ESF=227 MeV, Δt3=2.00 ms, assigned to 262Sg (SF decay)

Event #8:

Eα2=10306 keV 90, Δt2=5.40 ms, assigned to 266Hs

ESF=177 MeV, Δt3=33.91 ms, assigned to 262Sg (SF decay)

2012Ac04: 25 additional decay chains were observed at GSI using the same reaction and SHIP separator as in 2001Ho06. These chains were of three different types of correlations: EVR-α-α-SF, EVR-α-SF, and EVR-α-α-α-SF. Complete analysis of these data are yet to be published as mentioned in author’s review articles 2017Ac02 and 2015Ac04. Revised half-life of 270Ds α decay was deduced in this work. These experiments are also briefly described by d. Ackermann et al., in GSI Annual Scientific reports (GSI-2010, p200 (published in 2011), and GSI-2011, p208 (published in 2012))

For theoretical studies, consult Nuclear Science References (NSR) database at NNDC, BNL for 98 primary references dealing with the half-lives and other aspects of nuclear structure in this mass region

Q-value: Estimated uncertainty=470 for S(p) (2017Wa10)

Q-value: S(2n)=15110 310, S(2p)=2730 290, Q(εp)=2830 130 (syst, 2017Wa10)

Jπ(level) T1/2(level)
   0 0+ 0.20 ms +7-4 
% SF = ?
% α ≈ 100
  ≈1.13E3 (9-,10-) 3.9 ms +15-8 
% IT ≈ 30
% α ≈ 70

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Additional Level Data and Comments:

   00+ 0.20 ms +7-4 
% SF = ?
% α ≈ 100
Eα=11.03 MeV 5 (2001Ho06) from 270Ds α decay. Preliminary Q(α)=11.25 MeV (2012Ac04), fully analyzed results of this work are not yet available.
   1.13E3(9-,10-) 3.9 ms +15-8 
% IT ≈ 30
% α ≈ 70
Eα=10.95 MeV 2, 11.15 MeV 2 and 12.15 MeV 5 (2001Ho06) from α decay of the isomer in 270Ds to three different levels in 266Hs. Other: Eα=10.97, 11.20 and 12.11 MeV (2012Ac04, preliminary values from Fig. 4 in 2012Ac04).

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