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Radionuclide Dosimetric Data Sheets

Einsteinium-250m

Isotope:  Es-250m
Atomic number (Z):  99
Mass number (A):  250
Neutron number (N):  151

Decay modes:  β+, Electron capture
Half-life:  2.22 [h]
Decay constant:  8.6730e-05 [1/s]
Daughters:  Cf-250 (100.0%)
Radioactive daughters:  Cf-250

Mean alpha energy:  0.0 [MeV]
Mean electron energy:  0.03425 [MeV]
Mean photon energy:  0.5549 [MeV]
Air kerma rate constant, Γ₁₀:  2.902e-17 [Gy·m²/Bq·s]
Air kerma coefficient, K_air:  2.915e-17 [Gy·m²/Bq·s]
Equilibrium dose constant for weakly-penetrating radiations (α and/or electrons), Δ_wp:  5.487e-15 [Gy·kg/Bq·s]
Equilibrium dose constant for alphas, Δ_α:  0.000e+00 [Gy·kg/Bq·s]
Equilibrium dose constant for betas/electrons, Δ_β-,β+,e-:  5.487e-15 [Gy·kg/Bq·s]
Equilibrium dose constant for photons, Δ_p:  8.890e-14 [Gy·kg/Bq·s]

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-250m Summary Spectrum.csv

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-250m Beta Spectrum.csv

 

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-250m Summary Spectrum.csv

 

Energy [MeV]	Yield [#/nt] if > 0.01	Radiation type
7.45659e-05	1.389e+01	X-ray
3.85923e-03	1.049e-01	X-ray
1.31965e-02	1.715e-02	X-ray
1.54368e-02	2.556e-02	X-ray
1.56809e-02	2.243e-01	X-ray
1.90028e-02	4.900e-02	X-ray
1.96961e-02	1.380e-02	X-ray
1.97994e-02	1.007e-02	X-ray
2.07498e-02	1.603e-01	X-ray
2.09431e-02	1.000e-02	X-ray
2.42552e-02	3.832e-02	X-ray
1.10388e-01	2.215e-01	X-ray
1.15701e-01	3.426e-01	X-ray
1.29279e-01	4.012e-02	X-ray
1.30526e-01	7.927e-02	X-ray
1.34020e-01	1.023e-02	X-ray
1.34357e-01	2.123e-02	X-ray
6.26100e-01	1.176e-02	Gamma
8.28900e-01	5.488e-02	Gamma
9.89100e-01	1.333e-01	Gamma
1.03190e+00	1.058e-01	Gamma
1.16730e+00	2.940e-02	Gamma
1.17550e+00	1.568e-02	Gamma
1.20170e+00	1.225e-02	Gamma
1.61530e+00	1.764e-02	Gamma
1.65810e+00	1.029e-02	Gamma
1.14410e-04	3.757e+00	Auger electron
1.92098e-04	2.248e+00	Auger electron
2.11635e-04	1.730e-02	Auger electron
3.33187e-04	3.682e+00	Auger electron
6.35592e-04	6.432e-01	Auger electron
2.25939e-03	2.063e-01	Auger electron
2.79119e-03	1.177e+00	Auger electron
3.45095e-03	2.830e-01	Auger electron
4.20259e-03	1.835e-02	Auger electron
1.15939e-02	2.876e-01	Auger electron
1.55867e-02	1.545e-01	Auger electron
1.74790e-02	1.387e-01	Conversion electron
1.96242e-02	1.945e-02	Auger electron
2.27920e-02	1.137e-01	Conversion electron
3.76172e-02	7.353e-02	Conversion electron
4.27210e-02	2.712e-02	Conversion electron
8.68283e-02	1.327e-02	Auger electron

 

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

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

 

 

 

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