ADOPTED LEVELS, GAMMAS for 40Mg
Author: Balraj Singh | Citation: ENSDF | Cutoff date: 21-MAY-2021
Author: Balraj Singh | Citation: ENSDF | Cutoff date: 12-MAR-2019
Author: Jun Chen | Citation: Nucl. Data Sheets 140, 1 (2017) | Cutoff date: 30-Sep-2015
Full ENSDF file | Adopted Levels (PDF version)
| Q(β-)=20730 keV SY | S(n)= 1300 keV SY | S(p)= 27720 keV SY | Q(α)= -24850 keV CA | ||
| Reference: 2021WA16,2019MO01 |
| References: | |||
| A | C(41Al,40MgG) | B | C(42Si,40Mg) |
| E(level) (keV) | XREF | Jπ(level) | T1/2(level) | E(γ) (keV) | I(γ) |
| 0 | AB | 0+ | % β- = 100 % β-n = ? % β-2n = ? % B-3N = ? % B-4N = ? | ||
| 500 14 | A | (2+) | 500 14 | 100 |
Additional Level Data and Comments:
| E(level) | Jπ(level) | T1/2(level) | Comments |
| 0 | 0+ | % β- = 100 % β-n = ? % β-2n = ? % B-3N = ? % B-4N = ? | Theoretical T1/2=2.4 ms (2013Li39). |
First identification of 40Mg nuclide as particle stable by 2007Ba71.
2007Ba71: W(48Ca,Xγ),E=141 MeV/nucleon beam from the National Superconducting Cyclotron Laboratory (NSCL). The fragments were separated with the A1900 fragment separator. Isotopic identification by multiple ΔE signals, magnetic rigidity, total energy and time of flight analysis. Detectors: plastic scintillators, parallel-plate avalanche counters (PPACs) and silicon PIN diodes. α total of three events were assigned to 40Mg. This establishes stability of 40Mg against particle emission.
2014Cr02: C(42Si,40Mg), two-proton knockout reactions from 42Si at RIBF-RIKEN facility. Deduced inclusive cross section for 2p knockout from 42Si. α total of five events of 40Mg were observed for 9.65×105 incident 42Si nuclei.
2002Lu19 and 2002No11 (also 2003Pe31) searched for evidence for the production of 40Mg nuclide in fragmentation of 48Ca beam at 59, 64 MeV/nucleon bombarding a 181Ta target at RIKEN-RIPS facility. With a predicted cross section of 0.01 pb, only one event was expected; but none was observed. Thus the identification and particle stability of 40Mg remained uncertain in this work.
As concluded by 2019Cr02, level structure of 40Mg differs from that of the neighboring 38Mg and 36Mg nuclei, which the authors ascribe to possible weak-binding effects in the low-lying excitation spectrum. Their shell-model calculations are also not successful in reproducing the observed level energy of the first 2+ state.
Theory references: consult the NSR database (www.nndc.bnl.gov/nsr/) for 80 references for structure calculations.
Q-value: Q(α) from 2019Mo01 (theory), others from 2021Wa16
Q-value: Estimated uncertainties (2017Wa10): ΔQ(β-)=580, ΔS(n)=720, ΔS(p)=900
Q-value: S(2n)=670 710, Q(β-n)=19990 580 (syst,2021Wa16). S(2p)=53360 (theory,2019Mo01).
Q-value: Q(β-2n)=16940 520, Q(β-3n)=15930 530, Q(β-4n)=11320 530, Q(β-5n)=9820 500, Q(β-6n)=4120 500, Q(β-7n)=1550 500, deduced by evaluator from mass values in 2021Wa16.