<= Return to MIRDspec isotope database
Radionuclide Dosimetric Data Sheets
Einsteinium-249
Summary data
General
Classification
Isotope: Es-249
Atomic number (Z): 99
Mass number (A): 249
Neutron number (N): 150
Radioactive decay
Decay modes: α, β+, Electron capture
Half-life: 102.2 [m]
Decay constant: 1.1304e-04 [1/s]
Daughters: Cf-249 (99.4%), Bk-245 (0.57%)
Radioactive daughters: Cf-249, Bk-245
Dosimetric constants
Mean alpha energy: 0.0392 [MeV]
Mean electron energy: 0.04369 [MeV]
Mean photon energy: 0.41287 [MeV]
Air kerma rate constant, Γ10: 2.471e-17 [Gy·m2/Bq·s]
Air kerma coefficient, Kair: 2.472e-17 [Gy·m2/Bq·s]
Equilibrium dose constant for weakly-penetrating radiations (α and/or
electrons), Δwp: 1.328e-14 [Gy·kg/Bq·s]
Equilibrium dose constant for alphas, Δα: 6.281e-15
[Gy·kg/Bq·s]
Equilibrium dose constant for betas/electrons, Δβ-,β+,e-:
7.000e-15 [Gy·kg/Bq·s]
Equilibrium dose constant for photons, Δp: 6.615e-14
[Gy·kg/Bq·s]
Summary spectra (plot)
Spectra source: ICRP Publication 107: Nuclear Decay Data for Dosimetric Calculations. Ann. ICRP 2008, 38 (3).
Download tabulated summary spectra file here: www.mirdsoft.org/products/MIRDspecs/Es-249 Summary Spectrum.csv
Beta spectra (plot)
Spectra source: ICRP Publication 107: Nuclear Decay Data for Dosimetric Calculations. Ann. ICRP 2008, 38 (3).
Download tabulated beta spectra file here: www.mirdsoft.org/products/MIRDspecs/Es-249 Beta Spectrum.csv
Tabulated data
Summary spectra (table)
Spectra source: ICRP Publication 107: Nuclear Decay Data for Dosimetric Calculations. Ann. ICRP 2008, 38 (3).
Note: Radiations with yield < 0.01 are excluded from the table, but are available in the linked *.csv data.
Download tabulated summary spectra file here: www.mirdsoft.org/products/MIRDspecs/Es-249 Summary Spectrum.csv
|
Energy [MeV] |
Yield [#/nt] if > 0.01 |
Radiation type |
|
7.45509e-05 |
1.449e+01 |
X-ray |
|
3.85701e-03 |
1.086e-01 |
X-ray |
|
1.31965e-02 |
1.755e-02 |
X-ray |
|
1.54368e-02 |
2.616e-02 |
X-ray |
|
1.56809e-02 |
2.295e-01 |
X-ray |
|
1.90028e-02 |
5.014e-02 |
X-ray |
|
1.96961e-02 |
2.362e-02 |
X-ray |
|
1.97994e-02 |
1.031e-02 |
X-ray |
|
2.07498e-02 |
1.344e-01 |
X-ray |
|
2.09431e-02 |
1.712e-02 |
X-ray |
|
2.42553e-02 |
3.212e-02 |
X-ray |
|
1.10388e-01 |
2.441e-01 |
X-ray |
|
1.15701e-01 |
3.776e-01 |
X-ray |
|
1.29279e-01 |
4.421e-02 |
X-ray |
|
1.30526e-01 |
8.736e-02 |
X-ray |
|
1.34020e-01 |
1.127e-02 |
X-ray |
|
1.34357e-01 |
2.340e-02 |
X-ray |
|
3.75100e-01 |
3.314e-02 |
Gamma |
|
3.79500e-01 |
4.077e-01 |
Gamma |
|
7.89700e-01 |
1.155e-02 |
Gamma |
|
8.13200e-01 |
9.239e-02 |
Gamma |
|
1.21850e+00 |
1.516e-02 |
Gamma |
|
1.14366e-04 |
3.926e+00 |
Auger electron |
|
1.92819e-04 |
2.334e+00 |
Auger electron |
|
2.11612e-04 |
1.806e-02 |
Auger electron |
|
3.33602e-04 |
3.841e+00 |
Auger electron |
|
6.44590e-04 |
6.862e-01 |
Auger electron |
|
2.34609e-03 |
2.800e-01 |
Auger electron |
|
2.78924e-03 |
1.221e+00 |
Auger electron |
|
3.44954e-03 |
2.935e-01 |
Auger electron |
|
4.20198e-03 |
1.903e-02 |
Auger electron |
|
9.36002e-03 |
5.984e-02 |
Conversion electron |
|
1.16017e-02 |
2.937e-01 |
Auger electron |
|
1.55980e-02 |
1.578e-01 |
Auger electron |
|
1.69530e-02 |
2.435e-02 |
Conversion electron |
|
1.96425e-02 |
1.985e-02 |
Auger electron |
|
2.90930e-02 |
1.137e-02 |
Conversion electron |
|
3.19630e-02 |
1.102e-02 |
Conversion electron |
|
3.27680e-02 |
1.276e-02 |
Conversion electron |
|
3.64230e-02 |
2.923e-02 |
Conversion electron |
|
3.72280e-02 |
1.161e-02 |
Conversion electron |
|
3.74030e-02 |
1.328e-02 |
Conversion electron |
|
5.59700e-02 |
1.648e-02 |
Conversion electron |
|
5.73662e-02 |
1.218e-02 |
Conversion electron |
|
8.68283e-02 |
1.463e-02 |
Auger electron |
|
1.18943e-01 |
2.604e-02 |
Conversion electron |
|
1.19748e-01 |
1.139e-02 |
Conversion electron |
|
1.39886e-01 |
1.321e-02 |
Conversion electron |
Useful Links
Isotope decay characteristics are periodically updated as better measurements can be made - changes that may not be reflected on this page. Please see useful links:
National Nuclear Data Center (NNDC): https://www.nndc.bnl.gov/nudat3/mird/
International Atomic Energy Agency (IAEA) Livechart: https://www-nds.iaea.org/relnsd/vcharthtml/VChartHTML.html
Reference Links
ICRP Report 107: https://www.icrp.org/publication.asp?id=ICRP%20Publication%20107
Graves et al. Dose Point Kernels: https://doi.org/10.1002/mp.13789
MIRD Decay Schemes 2nd Edition: https://sites.snmmi.org/SNMMI-MAIN/iCore/Store/StoreLayouts/Item_Detail.aspx?iProductCode=0-932004-80-6
MIRDsoft MIRDspecs version 20250101 (www.mirdsoft.org)
<= Return to MIRDspec isotope database
