Search for ⁸¹Nb proved negative (2017Su26).

2001Ki13,1994He28: Production: fragmentation of 112 GeV ¹¹²Sn beam incident on a Be target; 0|’ magnetic spectrometer for determination of fragment trajectories (FWHM=0.32 for α, 0.23 for Z) prior to implantation into stack of 4 double-sided Si detectors with stacks of seven-fold segmented Si detectors on either side for β detection and surrounded by a segmented NaI detector and a Ge clover detector; measured correlation between implants and daughters, T_1/2 (2000StZU, 2001Ki13). Also, a few events (≈4 per 10^{14 106}Cd ions), apparently corresponding to ⁸¹Nb, were observed in Ni+¹⁰⁶Cd, E(¹⁰⁶Cd)=60 MeV/α using projectile fragment separator (fig. 1(b), 1994He28); however, the attribution of those events to contamination from neighboring peaks in the Z and Q spectra could not be ruled out (1994He28).

2017Su26: ⁸¹Nb nuclide searched for in ⁹Be(¹²⁴Xe,X), E(¹²⁴Xe)=345 MeV/nucleon beam produced by the cascade operation of the RIBF accelerator complex of the linear accelerators RILAC and RILAC-II and the four cyclotrons, RRC, fRC, IRC, and SRC. Identification of ⁸¹Nb nuclei was made on the basis of magnetic rigidity, time-of-flight and energy loss (tof-Bρ-ΔE method) of the fragments using BigRIPS fragment separator, atomic number Z of fragment by tof and ΔE, and α/Q (atomic mass/charge state) of fragment by Bρ and tof. Time-of-flight was measured using thin plastic scintillators, ΔE by MUSIC ionization chambers, and Bρ by particle trajectory reconstructions. Experiments were performed at RIBF-RIKEN facility. Measured α/Q versus Z distributions. No events were observed for ⁸¹Nb, indicating its unbound character towards proton emission. (Edited/Adapted the XUNDL dataset compiled by B. Singh (McMaster), Dec 22, 2017).

Q-value: ΔQ(β^-)=640, ΔS(n)=570, ΔS(p)=500, ΔQ(α)=450 (syst,2021Wa16)

Q-value: S(2n)=30850 640, S(2p)=3140 410, Q(εp)=7500 400 (syst,2021Wa16)