ADOPTED LEVELS for 31Ar
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-)=-22940 keV SY | S(n)= 18820 keV SY | S(p)= 640 keV SY | Q(α)= -8590 keV SY | ||
| Reference: 2021Wa16 |
| References: | |||
| A | 9Be(31Ar,31Ar’) | B | 9Be(32Ar,31Ar) |
| E(level) (keV) | XREF | Jπ(level) | T1/2(level) |
| 0 | AB | 5/2+ | 15.0 ms 3 % ε = 100 % β+p = 68.3 3 % β+2p = 8.9 2 % 2p < 0.0006 |
| 950 50 | A | ||
| 1580 60 ? | A | ||
| 2120 70 | A | ||
| 2.62E3 13 | A | ||
| 3.56E3 15 | A | ||
| 4.2E3 2 | A | ||
| X | A |
Additional Level Data and Comments:
| E(level) | Jπ(level) | T1/2(level) | Comments |
| 0 | 5/2+ | 15.0 ms 3 % ε = 100 % β+p = 68.3 3 % β+2p = 8.9 2 % 2p < 0.0006 | %ε+%β+ is primarily β+ (ε decay mode being negligible). E(level): %ε+%β+ is primarily β+ (ε decay mode being negligible). |
Other measurements:
1986La17: First identification of 31Ar isotope in reaction: Ni(40Ca,X) E=77 MeV/nucleon, at LISE-GANIL facility.
1987Bo36, 1991Bo32: 31Ar from fragmentation of 36Ar E=85 MeV/nucleon at LISE-GANIL facility. Measured delayed protons and 31Ar half-life. 1991Bo32 supersedes 1987Bo36
1989Re02: 31Ar from reaction: Mg(3He,X) E=110, 135 MeV at LBNL. Measured delayed one-proton and two-proton spectra, mass excess.
1990Bo24: 31Ar from Ca(p,xn3p) reaction E=600 MeV at CERN-ISOLDE facility. Measured delayed protons, pp-coin.
1992Ba01: 31Ar from fragmentation of 36Ar E=85 MeV/nucleon at LISE-GANIL facility. Measured delayed three-proton decay and half-life
1999Th09, 1998Ax01, 1998Ax02, 1998Mu06: 31Ar from Ca(p,X) E=1 GeV at CERN-ISOLDE facility. Measured delayed 2-proton spectra, angular correlations, recoil energy shift.
1999Fy01: 31Ar produced at CERN-ISOLDE facility. Measured Eβ, E(p), delayed multi-proton branching ratios, upper limit for 3-proton branch,
2000Fy01 (also 2000Bo59): 31Ar from Ca(p,X) E=1 GeV at CERN-ISOLDE facility. Measured delayed protons, 2-proton decay, p-p energy and angular correlations, 31Ar half-life. Note that 1998Ax02 (from the same group as 2000Fy01) proposed many additional levels based on their observed proton branches, but 2000Fy01 state that a number of assignments in 1998Ax02 of proton groups to corresponding levels in 31Cl were incorrect since the two-proton branches were not appropriately considered. The evaluators assume that data in 2000Fy01 supersede those in 1998Ax02.
2002Fy01, 2002Bo29: 31Ar from Ca(p,X) E=1 GeV at CERN-ISOLDE facility. Measured Ep, pβ coin, recoil energy shift
2014Ko17, 2013Ko13, 2014Ko34, 2016Ma17: 31Ar from Ca(p,X) at CERN-ISOLDE facility. Measured Eγ, E(p), I(p), pγ-coin, pp-coin, pp(θ), half-life of 31Ar decay with six DSSSDs and two Miniball cluster detectors.
2015Li20 (also 2016Ci05): 31Ar from 9Be(36Ar,X) E=880 MeV/nucleon at GSI. Measured E(p), I(p), 31Ar-p-coin using gaseous optical-readout time-projection chamber (OTPC). Deduced branching ratios for β+p, β+2p and β+3p modes.
Theoretical calculations: ten primary references for structure and eight for decay characteristics retrieved from the NSR database (www.nndc.bnl.gov/nsr/) are listed under ’document records’.
Q-value: ΔQ(β-)=360, ΔS(n)=270, ΔS(p)=200, ΔQ(α)=450 (syst,2021Wa16)
Q-value: Q(ε)=18360 200, S(2n)=42790 480, S(2p)=160 200, Q(εp)=18100 210 (syst,2021Wa16).
Q-value: Evaluators deduce Q(ε2p)=13705 200, Q(ε3p)=10956 200 from mass values in 2021Wa16