Author: Balraj Singh |  Citation: ENSDF |  Cutoff date: 09-SEP-2022 

Authors: A.A. Sonzogni, M. Fadil, and B. Pfeiffer |  Citation: Nucl. Data Sheets 110,2815 (2009) |  Cutoff date: 30-Sep-2009 

 Full ENSDF file | Adopted Levels (PDF version) 

Q(β-)=14054 keV 30S(n)= 2908 keV 30S(p)= 15090 keV SYQ(α)= -98404 keV SY
Reference: 2021WA16

General Comments:

1991Kr15: 84Ga produced and identified in 238U(p,F),E=600 MeV, followed by mass separation of fission products. Measured β-delayed neutrons, T1/2 and %β-n from the decay of 84Ga at CERN-ISOLDE facility.

2003Pe18, 2006Pe20: 238U(n,f), measured Eγ, Iγ, γ(t), γγ-coin, βγ-coin following mass separation by ISOL method at the PARRNe facility in Orsay.

2009Le26 (also 2009Ve11): 84Ga isotope produced in U(γ,F),E=50 MeV reaction at PARRNe on-line mass separator within the ALTO facility. Bremsstrahlung beam was produced by 50-MeV electron beam hitting a UCx target, followed by mass separation of fission fragments. Measured Eγ, Iγ, βγ-coin. The authors propose an isomer based on the gamma intensities from 84Ge β- decay and 84Ga β-delayed neutron decay.

2010Wi03 (also 2009Gr06): 84Ga produced in 238U(p,F),E(p)=54 MeV reaction. Reaction products were accelerated to 225 MeV in the ORNL Tandem van de Graaff generator. Measured Eγ, Iγ, γγ-coin, (fragment)γ-coin, (ion-tagged γ-ray spectra), βγ(ion)-coin, βnγ-coin using an array composed of four Ge clover and two plastic scintillator detectors. Comparison with spherical HFB calculations. No evidence was found for the existence of two isomers in 84Ga, as was proposed in 2009Le26. 2010Wi03 state that 1046γ is in 83Ge, not in 84Ge as was suggested by 2009Le26.

2013Ko32: 84Ga produced in U(γ,F),E=50 MeV, the bremsstrahlung beam was produced in 50 MeV (10 μA) electron beam incident on a thick UCx target. It was followed by selective photoionization using the ALTO resonant laser ion source. 84Ga was then mass separated at the PARRNe online mass separator at IPN, Orsay facility, and implanted on Al-coated mylar tape. Measured Eγ, Iγ, γγ-coin, βγ-coin and T1/2 of 84Ga isotope using two HPGe detectors and a plastic scintillator.

2016Ma50: 84Ga isotope produced in the reaction U(p,F),E(p)=50 MeV, at the RIB-HRIBF-ORNL facility, where the 84Ga radioactive ion beam was extracted, mass separated and transmitted to the Low Energy Radioactive Ion Beam Spectroscopy Station. Measured Eγ, Iγ, E(n), I(n), E(β), nβ-coin using two HPGe detectors, the VANDLE array of 48 plastic scintillators for neutron time-of-flight measurements, and two plastic scintillators surrounding the implantation point for β particles. Deduced β-delayed neutron emission probability or Pn

2017Ve01: radioactive ion beam of 84Ga at 30 keV was produced in photofission of 238U using UCx pellets containing about 60 g of 238U. The photons were created by 50-MeV primary electron beam bombarding a Ta target heated up to ≈2000|’C. The Ga atoms were ionized with the Resonant Ionization Laser Ion source (RILIS) using a two-step ionization system. Extracted 30 keV ion beam was delivered to PARRNe on-line separator at ALTO ISOL facility. Mass-separated 84Ga beam was then sent to β-decay counting station BEDO where it was collected on mylar tape at the center of the detection system of 4π 3He neutron counter TETRA, an HPGe detector for γ radiation and plastic 4πβ array for electrons. Measured Eγ, Iγ, β spectrum, β-gated γ and β(neutron)-gated γ spectra, delayed neutrons, %β-n of 84Ga decay for 17971 counting cycles in beam-off and beam-on collection/counting steps. The measurements reported in this work were a test case for the 3He neutron-counter TETRA installed behind the PARRNe mass separator at the electron-driven ALTO-ISOL facility. Experimental details are given in 2016Te09

2019Yo03: 84Ga produced in 9Be(238U,F),E(238U)=345 MeV/nucleon on a 4-mm thick 9Be target at the RIBF-RIKEN facility. Fragments separated and identified using the BigRIPS separator, then implanted into active stoppers consisting of double-sided silicon strip detectors. Measured Eγ, Iγ, E(n), I(n), nβ-coin, T1/2, %β-n using two HPGe detectors for γ rays and the BRIKEN detector consisting of 140 3He counters for neutrons.

Mass measurement: 2020Re04

No evidence for an isomer with T1/2<0.085 s and Jπ=(3-,4-) as proposed in 2009Le26

In literature, there are no studies of decay of 84Zn to 84Ga, with an exception that 2014XuZZ report T1/2 of decay of 84Zn by β(108.5γ)-coin method, implying that 108.5-keV γ ray possibly deexcites a level in 84Ga.

Q-value: Estimated uncertainties (2021Wa16): 300 for S(p) and Q(α)

Q-value: Q(β-n)=8811 30, S(2n)=7306 30, S(2p)=32940 400 (syst) (2021Wa16). Q(β-2n)=5180 30 (deduced by evaluator from mass excesses in 2021Wa16)

Jπ(level) T1/2(level)
  0 (0-) 95.2 ms 24 
% β- = 100
% β-n = 46 5
% β-2n = 1.6 2

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Additional Level Data and Comments:


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