ADOPTED LEVELS for 31Cl
Authors: Jun Chen and Balraj Singh | Citation: Nucl. Data Sheets 184, 29 (2022) | Cutoff date: 24-Jun-2022
Full ENSDF file | Adopted Levels (PDF version)
| Q(β-)=-18360 keV SY | S(n)= 19780 keV 24 | S(p)= 264 keV 3 | Q(α)= -8800 keV 10 | ||
| Reference: 2021WA16 |
| References: | |||
| A | 31Ar ε decay (15.0 MS) | B | PB(31Cl,31Cl’) |
| E(level) (keV) | XREF | Jπ(level) | T1/2(level) |
| 0 | AB | 3/2+ | 190 ms 1 % ε = 100 % εp = 2.4 2 |
| 737 22 | AB | (1/2+) | |
| 1728 4 | AB | (5/2)+ | |
| 2418 4 | A | (3/2,5/2,7/2)+ | |
| 2593 4 | A | (3/2,5/2,7/2) | |
| 2669 5 | A | (3/2,5/2,7/2)+ | |
| 3622 5 | A | (3/2,5/2,7/2) | |
| 4020 4 | A | (3/2,5/2,7/2)+ | |
| 5365 4 | A | (3/2,5/2,7/2)+ | |
| 5598 4 | A | (3/2,5/2,7/2)+ | |
| 5731 7 | A | (3/2,5/2,7/2)+ | |
| 6512 4 | A | (3/2,5/2,7/2)+ | |
| 6640 7 | A | (5/2,7/2)+ | |
| 6825 14 | A | (3/2,5/2,7/2) | |
| 7361 3 | A | (3/2,5/2,7/2)+ | |
| 7465 9 | A | (3/2,5/2,7/2)+ | |
| 7576 10 | A | (3/2,5/2,7/2) | |
| 7919 8 | A | (3/2)+ | |
| 9416 5 | A | (3/2,5/2,7/2)+ | |
| 12282 7 | A | 5/2+ | |
| 12521 30 | A | (3/2,5/2,7/2)+ |
E(level): From 31Ar ε decay, unless otherwise noted.
Additional Level Data and Comments:
| E(level) | Jπ(level) | T1/2(level) | Comments |
| 0 | 3/2+ | 190 ms 1 % ε = 100 % εp = 2.4 2 | Dominant d-wave component for the valence proton in 31Cl deduced from the measured momentum distribution and Glauber analysis in 12C(31Cl,30S) reaction (2011Fu11). |
| 737 | (1/2+) | Resonance energy E(p)=472 keV 14 as average of measured values of E(p)(lab)=446 15 or E(p)(c.m.)=461 15 (1998Ax02); and E(p)(c.m.)=517 32 (from level energy=782 32 in 2014La09 and S(p)=264.6 34 from 2016Ka15). Evaluators obtain a weighted average of 471 22 from the two values. E(level): Resonance energy E(p)=472 keV 14 as average of measured values of E(p)(lab)=446 15 or E(p)(c.m.)=461 15 (1998Ax02); and E(p)(c.m.)=517 32 (from level energy=782 32 in 2014La09 and S(p)=264.6 34 from 2016Ka15). Evaluators obtain a weighted average of 471 22 from the two values. | |
| 1728 | (5/2)+ | Resonance energy E(p)=1464 keV 2, as average of measured values of E(p)(lab)=1416 2 or E(p)(c.m.)=1463 2 (2000Fy01) and E(p)(c.m.)= 1528 26 (from level energy=1793 26 in 2014La09 and S(p)=264.6 34 from 2016Ka15). Evaluators obtain a weighted average of 1463 5 from the two values. E(level): Resonance energy E(p)=1464 keV 2, as average of measured values of E(p)(lab)=1416 2 or E(p)(c.m.)=1463 2 (2000Fy01) and E(p)(c.m.)= 1528 26 (from level energy=1793 26 in 2014La09 and S(p)=264.6 34 from 2016Ka15). Evaluators obtain a weighted average of 1463 5 from the two values. Jπ(level): (3/2,5/2,7/2)+ from log ft<5.9 from 5/2+. | |
| 2418 | (3/2,5/2,7/2)+ | Jπ(level): (3/2,5/2,7/2)+ from log ft<5.9 from 5/2+. | |
| 2593 | (3/2,5/2,7/2) | Jπ(level): From log ft>5.9, log f1ut<8.5 from 5/2+. | |
| 2669 | (3/2,5/2,7/2)+ | Jπ(level): (3/2,5/2,7/2)+ from log ft<5.9 from 5/2+. | |
| 3622 | (3/2,5/2,7/2) | Jπ(level): From log ft>5.9, log f1ut<8.5 from 5/2+. | |
| 4020 | (3/2,5/2,7/2)+ | Jπ(level): (3/2,5/2,7/2)+ from log ft<5.9 from 5/2+. | |
| 5365 | (3/2,5/2,7/2)+ | Jπ(level): (3/2,5/2,7/2)+ from log ft<5.9 from 5/2+. | |
| 5598 | (3/2,5/2,7/2)+ | Jπ(level): (3/2,5/2,7/2)+ from log ft<5.9 from 5/2+. | |
| 5731 | (3/2,5/2,7/2)+ | Jπ(level): (3/2,5/2,7/2)+ from log ft<5.9 from 5/2+. | |
| 6512 | (3/2,5/2,7/2)+ | Jπ(level): (3/2,5/2,7/2)+ from log ft<5.9 from 5/2+. | |
| 6640 | (5/2,7/2)+ | Jπ(level): From 2014Ko17 in 31Ar ε decay based on pp(θ) analysis. | |
| 6825 | (3/2,5/2,7/2) | Jπ(level): From log ft>5.9, log f1ut<8.5 from 5/2+. | |
| 7361 | (3/2,5/2,7/2)+ | Jπ(level): (3/2,5/2,7/2)+ from log ft<5.9 from 5/2+. | |
| 7465 | (3/2,5/2,7/2)+ | Jπ(level): (3/2,5/2,7/2)+ from log ft<5.9 from 5/2+. | |
| 7576 | (3/2,5/2,7/2) | Jπ(level): From log ft>5.9, log f1ut<8.5 from 5/2+. | |
| 7919 | (3/2)+ | Jπ(level): From 2014Ko17 in 31Ar ε decay based on pp(θ) analysis. | |
| 9416 | (3/2,5/2,7/2)+ | Jπ(level): (3/2,5/2,7/2)+ from log ft<5.9 from 5/2+. | |
| 12521 | (3/2,5/2,7/2)+ | Jπ(level): (3/2,5/2,7/2)+ from log ft<5.9 from 5/2+. |
Mass measurement: 2016Ka15 (mass excess=-7034.7 keV 34), 1977Be13 (-7070 keV 50)
Other measurements:
1982Ay01: 31Cl from 32S(p,2n) E=33 MeV, Oslo cyclotron, ZnS target. Measured β-delayed proton spectra, γ-ray spectra.
2006Ka11: 31Cl from 32S(p,2n) E=40,45 MeV, IGISOL, ZnS target. Measured delayed proton energies E(p), Eγ, I(p), Iγ and pγ coin
2011Fu11: 31Cl from 9Be(36Ar,X) E=82 MeV/nucleon at RIBLL-HIRFL and incident on a carbon target. Measured longitudinal fragment momentum distribution of 30S after one-proton removal from 31Cl.
2011SaZM: 31Cl produced in 32S(p,2n) E=40 MeV/nucleon reaction and separated using MARS recoil spectrometer at Texas A&M University accelerator facility. Measured Eγ, Iγ, γγ, Ep, Ip, half-life
2016Ka15: mass excess of 31Cl, produced in 32S(p,2n), E=40 MeV, measured using JYFLTRAP double-Penning-trap mass spectrometer at the IGISOL facility. Analysis of IMME for t=3/2 quartet in α=31 nuclides.
Measured mass excess=-7034.7 keV 34 (2016Ka15). From this value, authors deduce S(p)(31Cl)=264.6 keV 34 (value in 2021Wa16: AME-2020 is 264 keV 3). The new value of S(p) combined with the β-delayed proton decay data for 31Ar is used by 2016Ka15 to obtain revised values of level energies and proton resonances of 31Cl. Authors analyze quadratic form of the isobaric multiplet mass equation (IMME) for t=3/2 quartet at α=31 (31Cl, 31S, 31P and 31Si), and find that the quadratic form of the IMME breaks down giving reduced χ2=11.6, while a cubic equation fits with a non-zero cubic term d=-3.5 keV 11 or -4.3 keV {11 if energy of the IAS state in 31S is used as 6279.0 keV 6 from 2016Be05. This value of IAS gives reduced χ2 of 16.2 for a quadratic fit. The two lowest levels in 31Cl are relevant to radiative resonant proton captures in the rp process.
2018Be12, 2016Be05, 2016Be19: 31Cl from 9Be(36Ar,X) E=150 MeV/nucleon at NSCL. Measured Eγ, Iγ, βγ-coin. IMME analysis.
Theoretical calculations: 11 primary references for structure and two for decay characteristics retrieved from the NSR database (www.nndc.bnl.gov/nsr/) are listed under ’document records’.
Q-value: ΔQ(β-)=200 (syst,2021Wa16)
Q-value: S(2n)=37200 190 (syst), S(2p)=4660 3, Q(εp)=5877 3, Q(ε)=12008 3 (2021Wa16)