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Radionuclide Dosimetric Data Sheets

Curium-251

Isotope:  Cm-251
Atomic number (Z):  96
Mass number (A):  251
Neutron number (N):  155

Decay modes:  β-
Half-life:  16.8 [m]
Decay constant:  6.8765e-04 [1/s]
Daughters:  Bk-251 (100.0%)
Radioactive daughters:  Bk-251

Mean alpha energy:  0.0 [MeV]
Mean electron energy:  0.45445 [MeV]
Mean photon energy:  0.11124 [MeV]
Air kerma rate constant, Γ₁₀:  5.286e-18 [Gy·m²/Bq·s]
Air kerma coefficient, K_air:  5.286e-18 [Gy·m²/Bq·s]
Equilibrium dose constant for weakly-penetrating radiations (α and/or electrons), Δ_wp:  7.281e-14 [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-:  7.281e-14 [Gy·kg/Bq·s]
Equilibrium dose constant for photons, Δ_p:  1.782e-14 [Gy·kg/Bq·s]

Dose point kernel source:  Graves, et al. Medical Physics. 2019 Nov.; 46(11):5284-5293.

Note: Bins are spaced every 0.1 mm until a radius of 10 cm, and every 1 mm until a radius of 2 m.

Download tabulated dose point kernel file here:  www.mirdsoft.org/products/MIRDspecs/Cm-251 DPK.csv

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/Cm-251 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/Cm-251 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/Cm-251 Summary Spectrum.csv

 

Energy [MeV]	Yield [#/nt] if > 0.01	Radiation type
7.84606e-05	1.714e+00	X-ray
3.75036e-03	1.233e-02	X-ray
1.53277e-02	2.567e-02	X-ray
2.01361e-02	1.123e-02	X-ray
1.07707e-01	2.027e-02	X-ray
1.12748e-01	3.154e-02	X-ray
3.89700e-01	1.275e-02	Gamma
4.38200e-01	1.243e-02	Gamma
5.30000e-01	1.624e-02	Gamma
5.42700e-01	1.090e-01	Gamma
5.62500e-01	1.025e-02	Gamma
9.78200e-01	1.003e-02	Gamma
1.26562e-01	1.699e-02	Beta
2.66564e-01	3.299e-02	Beta
2.73606e-01	1.399e-01	Beta
3.10959e-01	1.999e-02	Beta
3.16741e-01	3.499e-02	Beta
3.72754e-01	1.999e-02	Beta
4.73751e-01	7.297e-01	Beta
1.03825e-04	4.719e-01	Auger electron
1.90650e-04	2.721e-01	Auger electron
3.03434e-04	4.538e-01	Auger electron
6.25965e-04	8.195e-02	Auger electron
2.21949e-03	4.188e-02	Auger electron
2.72188e-03	1.441e-01	Auger electron
3.35091e-03	3.333e-02	Auger electron
7.20600e-03	3.128e-02	Conversion electron
1.13585e-02	3.382e-02	Auger electron
1.52419e-02	1.802e-02	Auger electron
1.01390e-01	1.208e-02	Conversion electron
4.10490e-01	2.930e-02	Conversion 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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