ADOPTED LEVELS, GAMMAS for 268Db
Author: Balraj Singh | Citation: Nucl. Data Sheets 156, 148 (2019) | Cutoff date: 31-Jan-2019
Full ENSDF file | Adopted Levels (PDF version)
| Q(β-)=260 keV SY | S(n)= 5080 keV SY | S(p)= 3670 keV SY | Q(α)= 8260 keV SY | ||
| Reference: 2017WA10 |
| References: | |||
| A | 272Bh α decay (10.5 S) | ||
| E(level) (keV) | XREF | T1/2(level) | E(γ) (keV) |
| 0 | A | 28 h 3 % ε = ? % α = ? % SF ≈ 100 | |
| ≈140 | A | ≈140 |
Additional Level Data and Comments:
| E(level) | Jπ(level) | T1/2(level) | Comments |
| 0 | 28 h 3 % ε = ? % α = ? % SF ≈ 100 | Only the SF decay mode has been observed, however, 2015Og05 (also 2015Og01) review article states that α or ε/β+ decay mode is not excluded. |
| E(level) | E(gamma) | Comments |
| 140 | 140 | E(γ): from 2013Ru11, based on Eα values. Authors mention that the simulated γ-ray yield is marginal and consistent with an empty spectrum from the Ge detector. |
The 268Db nuclide is produced in about 100 (or 113) correlated decay chains observed at Dubna, GSI and Berkeley, starting from 288Mc and ending in 268Db, which decays by SF. Main references for production of 288Mc: 2004Og03, 2005Og02, 2005Dm03, 2012Og02, 2013Ru11, 2015Ru11, 2013Og01, 2015Ga24, 2016Fo10. See 288Mc Adopted Levels for details.
2005Dm03: 243Am(48Ca,3n),E=247 MeV by the FLNR-JINR-Dubna U-400 cyclotron. The beam bombarded a 243Am target backed by Ti foils and including Cu as a catcher material. Reaction products, including products of the Cu(48Ca,X) reaction were dissolved in concentrated HNO3. Group V elements were separated from the solution by separating the reaction products from Cu via co-precipitation with lanthanum hydroxide and separating Group V elements from lanthanum and actinides via sorption from nitric acid. The α and spontaneous fission fragments were detected by a module with four identical chambers, each containing two semiconductor detectors. The four chambers were positioned inside a neutron detector containing 72 3He counters positioned in a polyethylene moderator. α similar experiment was also performed, involving the same reaction but the reaction products were not separated. The detectors were exposed for 72 days, during which they were changed at intervals and subjected to physico-chemical treatment to develop latent tracks of spontaneous fission fragments. Deduced that all spontaneous fission events detected in the 243Am(48Ca,X) reaction were attributable to the decay chain of the element 115.
2007St18: chemical identification of long-lived isotope of Db, a descendant of 288Mc, produced in 243Am(48Ca,3n) with a beam energy of 247 MeV. The chemical experiments provided evidence that the element was a +5 element, thus supporting the assignment as 268Db. Measured half-life of 268Db from all the events.
For theoretical studies, consult Nuclear Science References (NSR) database at NNDC, BNL for 51 primary references dealing with the half-lives and other aspects of nuclear structure in this mass region
Q-value: Estimated uncertainties (2017Wa10): ΔQ(β-)=710, ΔS(n)=670, ΔS(p)=780, ΔQ(α)=300
Q-value: S(2n)=11820 600, S(2p)=9140 790 (syst,2017Wa10)