Authors: Jun Chen and Balraj Singh |  Citation: Nucl. Data Sheets 177, 1 (2021) |  Cutoff date: 3-Sep-2021 

 Full ENSDF file | Adopted Levels (PDF version) 

S(n)= 11390 keV 30S(p)= 1497 keV 27Q(α)= 7862 keV 10
Reference: 2021WA16

General Comments:

2006An36 (also 2007An19): 194Rn produced and identified in 144Sm(52Cr,2n) reaction at E=236 MeV, using 144SmF3 rotating target onto a carbon backing at the UNILAC heavy-ion facility at GSI, with SHIP velocity filter for separating evaporation residues. Detector system consisted of different types of detectors. The decays of the evaporation residues were measured by implanting residues in a thick 16-strip position-sensitive silicon detector (PSSD) with a typical FWHM ≈ 20 keV for α particles in 6-8 MeV range. An array of six silicon detectors of similar shape (BOX detectors), mounted upstream of PSSD detector, was used to measure the energies of α, β and conversion electrons. Three thin time-of-flight detectors in front of the PSSD and BOX detectors permitted identification of reaction products from the scattered beam particles; and distinction between the decay events and implantation events through anti-coincidence technique. An additional thick Si detector was installed as a veto detector behind the PSSD detector in an anti-coincidence mode. This allowed distinction between the decays and the punch-through events (from high-energy protons and α particles produced in the reactions on the carbon backing). For γ rays, a four-fold segmented ’Clover’ Ge detector was used behind the PSSD detectors for prompt and delayed γ(residues) coin and/or αγ coin measurements. Identification of the isotope by time and position correlation of α decays from 194Rn with the known α decays from daughter isotope 190Po and grand-daughter 186Pb. Measured α, γ, αγ coin, α(residues) coin, γ(residues) coin.

Theoretical references: consult the NSR database ( for 18 primary references dealing with decay modes and structure calculations.

Q-value: S(2p)=787 20, Q(ε)=6441 29, Q(εp)=6761 22 (2021Wa16) S(2n)=20380 (theory,2019Mo01)

Jπ(level) T1/2(level)
  0 0+ 0.78 ms 16 
% α ≈ 100

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Additional Level Data and Comments:

  00+ 0.78 ms 16 
% α ≈ 100
Production cross section (at E(52Cr)=232 MeV)=120 pb 50 (2006An36).

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