Authors: J.E. Purcell, C.G. Sheu |  Citation: Nucl. Data Sheets 130 1 (2015) |  Cutoff date: 30-Jun-2015 

 Full ENSDF file | Adopted Levels (PDF version) 

Q(β-)=18.5906 keV 32S(n)= 6257.233 keV 2
Reference: 2012WA38

  A  1H(6He,α)  B  2H(n,γ) E=THERMAL
  C  2H(n,n)  D  3H(γ,n),(γ,NN)
  E  3H(E,E) 

General Comments:

The discovery of hydrogen isotope 3H with an estimate of its mass was reported in 1934; see (2012Th01) for a historical review. In (1947Bl31,1947Bl32) it is shown that the spin of 3H is 1/2 and the ratio of the magnetic moment of 3H to that of the proton is found to be 1.067 1. For the 3H spin, see also (1949Di31).

Calculations show that the ground state wave functions of 3H and 3He consist of a spatially symmetric S state (≈90%), a d state (≈9%), a mixed symmetry S’ state (≈1%) and a small p state (<0.1%). See (1979Sa15,1986Is01,1987Er07,1993Wu08,2002Ho09).

The ratio |ct of the asymptotic d state to S state of 3H is -0.0418 31. This value is the inverse square of the uncertainty weighted average of the two most recent measurements (1993Ge04,1994Ko29). The following table lists references reporting values for |ct:

Also see (1988Fr01) where it was noted that there is a strong correlation between the triton and deuteron asymptotic ratios. Using several models, they obtained |ct/|cd=1.68 4. Using this ratio value and |cd=0.0256 4 from (1990Ro02) gives |ct=-0.0430 12.

The charge and magnetic rms radii for 3H are rc=1.755 fm 86 and rm=1.840 fm 181 (1994Am07). See (2005Go26) for electric and magnetic form factors for 3H and 3He as well as isoscalar and isovector versions and comparison with theory. Also see the reaction 3H(e,e)3H below for more details.

Triton magnetic moment, μt=+2.978962467 26 μN. This value is obtained from a measurement of the ratio of the triton to proton magnetic moments μtp=1.0666399151 30 (2011Ne15) and the value of the proton magnetic moment μp=+2.792847356 23 μN reported in (2014Ol01). Also see Table XLI of (2012Mo42) which gives μt=2.978962448 38.

XREFJπ(level) T1/2(level)
  0.0AB    1/2+ 12.32 y 2 
% β- = 100

Back to top

Back to top

Additional Level Data and Comments:

  0.01/2+ 12.32 y 2 
% β- = 100
μ=+2.978962467 26
3H binding energy: 8481.7986 keV 24; S(n)=6257.2327 keV 22 using mass excess values from (2012Wa38).
E(level): 3H binding energy: 8481.7986 keV 24; S(n)=6257.2327 keV 22 using mass excess values from (2012Wa38).

Back to top