Author: Filip G Kondev |  Citation: ENSDF |  Cutoff date: 20-Feb-2017 

 Full ENSDF file | Adopted Levels (PDF version) 

Q(β-)=5.84×103 keV 3S(n)= 4.06×103 keV 20S(p)= 12183 keV 202Q(α)= -3977 keV 202
S(2n)= 1.032×104 keV 20S(2p)= 23259 keV 202
Reference: 2017WA10

General Comments:

2012Ku26: 157Nd produced and identified in 9Be(238U,F), E=1 GeV/nucleon reaction using SIS-18 synchrotron facility at GSI. Target=1.6 g/cm2 9Be placed at the entrance of projectile Fragment Separator (FRS). Particle identification was achieved by event-by-event in-flight analysis of time-of-flight, energy loss measurement, and magnetic rigidity (tof-ΔE’-Bρ). Time-of-flight measured using two plastic scintillation detectors, energy loss or deposit by ionization chambers (MUSIC), and magnetic rigidity by four time-projection chambers (TPC), which also provided energy deposit information. Isomer tagging method for known μs isomers was used to verify event-by-event identification and in-flight separation of new isotopes. Gamma rays from the known isomers were recorded in coincidence with the incoming ions using either the RISING array of Ge detectors at GSI or only two Ge detectors, a stopper foil and a scintillator for veto signal. Measured production cross section. Comparison of measured σ with predictions from ABRABLA model and EPAX-3 model

2017Wu04: The 157Nd nuclide was produced at the RIBF-RIKEN facility using the 9Be(238U,F) reaction at E=345 MeV/nucleon. Two experiments, optimized for the transmission of 158Nd and 170Dy ions, were carried out with average beam intensities of 7 pnA and 12 pnA, respectively. The identification of the nuclide of interest was made in the BigRIPS separator by determining the atomic number and the mass-to-charge ratio of the ion using the tof-Bρ-ΔE method. The reaction products were transported through the ZeroDegree Spectrometer and implanted into the beta-counting system WAS3ABi that was surrounded by the EURICA array comprising of 84 HPGe detectors. The typical implantation rate was ~100 ions/s. Measured: implanted ion-β--t, implanted ion-β--γ-t and implanted ions-γ-t correlations. Deduced: T1/2.

2012Va02: Penning-trap mass measurement using mass-separated fragments from the 252Cf source at the CARIBU-ANL facility

Earlier secondary reports for possible identification of the 157Nd isotope:

1992ShZG: tentative identification of 157Nd in the decay of a mass separated sample. Authors observed Pm K x rays and γ rays with T1/2 of several seconds, which they tentatively identified as from the decay of 157Nd.

1997Be12, 1995CzZZ: Pb(238U,X),E=750 MeV/nucleon by SIS synchrotron at GSI using FRS separator at an experiment run in 1992. These reports seem to suggest observing 157Nd, but no experimental details, such as production cross section or α/Z fragment yield plots, were given. The production of 157Nd was not mentioned in any of the regular publications of the GSI group (1994Be24, 1997Be70, 2003Be45, 2007Pe01).

Jπ(level) T1/2(level)
  0.0 (5/2-) 1.15 s 3 
% β- = 100

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Additional Level Data and Comments:

  0.0(5/2-) 1.15 s 3 
% β- = 100
Production σ(at 1 GeV/nucleon)=980 nb 40 (2012Ku26).

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