ADOPTED LEVELS, GAMMAS for 86As
Authors: A. Negret and B. Singh | Citation: Nucl. Data Sheets 203, 283 (2025) | Cutoff date: 20-Jan-2025
Full ENSDF file | Adopted Levels (PDF version)
| Q(β-)=11541 keV 4 | S(n)= 3844 keV 5 | S(p)= 13128 keV 5 | Q(α)= -8456 keV 4 | ||
| Reference: 2021WA16 |
| References: | |||
| A | 86Ge β- decay (221.6 MS) | ||
| E(level) (keV) | XREF | Jπ(level) | T1/2(level) | E(γ) (keV) | I(γ) | Final Levels | |
| 0.0 | A | (1-,2-) | 0.945 s 8 % β- = 100 % β-2n = ? % β-n = 35.5 6 | ||||
| 7.1 4 | A | ||||||
| 21.3 6 | A | ||||||
| 118.9 3 | A | 97.6 5 111.8 3 118.9 3 | 11.6 29 100 7 61 8 | 21.3 7.1 0.0 | (1-,2-) | ||
| 244.3 4 | A | 125.4 3 | 100 | 118.9 | |||
| 309.2 4 | A | 190.3 3 | 100 | 118.9 | |||
| 402.5 6 | A | 283.6 5 | 100 | 118.9 | |||
| 447.4 6 | A | 328.5 5 | 100 | 118.9 | |||
| 481.8 6 | A | 362.9 5 | 100 | 118.9 | |||
| 2084.3 4 | A | (1+) | 1965.4 3 | 100 | 118.9 | ||
| 2916.9 10 | A | 2798 1 | 100 | 118.9 | |||
E(level): From least-squares fit to Eγ data
Additional Level Data and Comments:
| E(level) | Jπ(level) | T1/2(level) | Comments |
| 0.0 | (1-,2-) | 0.945 s 8 % β- = 100 % β-2n = ? % β-n = 35.5 6 | Theoretical values: T1/2=0.370 s, %β-n=5.3, 8.5; %β-2n=0.0 (2021Mi17); two values for two different fission barriers. |
86As produced and identified by 1973Kr06 (also 1974KrZG,1975Kr08) in neutron-induced fission of 235U followed by chemical separation and half-life measurement. Earlier studies (1966To02,1967De01,1968To18,1968To19,1969WaZS) reported decays of mixed 85As and 86As activities by observing the decay of its descendants 86Se and 86Br, and by counting of delayed neutrons after separation of arsenic sample from other fission products of 235U. α 2-s half-life reported for this mixture most likely corresponded to 85As activity
T1/2 and %β-n measurements: 2013Ma22, 1993Ru01, 1978Cr03, 1973Kr06 (also 1974KrZG,1975Kr08)
Precise mass measurements: 2008Ha23 (Penning-trap method), 2008Su19 (also 2010Li02) (isochronous mass spectrometry)
2013Ma22: 50-MeV proton beam provided by the Oak Ridge Isochronous Cyclotron (ORIC) at the HRIBF-ORNL facility incident on 238UCx. Fission fragments were ionized to charge state +1 then purified using H2S gas, a mass pre-separator and electromagnetic separation. The purified beams were then sent to the Low-energy Radioactive Ion Beam Spectroscopy Station (LeRIBSS) and implanted in a moving tape collector (MTC). Measured Eγ, Iγ, Eβ, βγ-coin, half-life of 86As g.s. using two plastic scintillation counters and four HPGe detectors. Comparison with the gross theory of β decay, the finite-range droplet model and the continuum quasiparticle random-phase approximation.
2020ToZY: 87Ge produced in 9Be(238U,F), E=345 MeV/nucleon; followed by separation of fragments by α/Q and Z using BigRIPS and ZeroDegree spectrometers at RIBF-RIKEN facility through measurements of time-of-flight (tof), magnetic rigidity (Bρ) and energy loss (ΔE). Measured implanted ions, neutrons, β, γ, β(implants), (implants)β(1n)- and (implants)β(2n)-correlations using BRIKEN neutron counter with 140 3He-filled proportional counters, AIDA array of DSSSDs for implants and β decays, two Clover HPGe detectors for γ radiation, and two thick plastic scintillators; deduced %β-n=33.5 16 and %β-2n=0.22 16 from simultaneous fits of β-- and β-1n-decay curves, with uncertainties from Monte Carlo method. Q(87Ge β-n decay)=7300 300 and Q(88Ge β-2n decay)=3300 400 are estimated by evaluators from relevant mass excesses in 2021Wa16. T1/2(87Ge β-n decay)=103.2 35 ms and T1/2(88Ge β-2n decay)=60.8 61 ms (β-decay curve in 2014XuZZ).
No references for theoretical structure calculations in the NSR database.
Q-value: S(2n)=9251 5, S(2p)=29450 30, Q(β-n)=5380 4 (2021Wa16). Q(β-2n)=310 440 deduced by evaluators from relevant mass values in 2021Wa16