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Radionuclide Dosimetric Data Sheets

Berkelium-251

Summary data

General

Classification

Isotope:  Bk-251
Atomic number (Z):  97
Mass number (A):  251
Neutron number (N):  154

Radioactive decay

Decay modes:  β-
Half-life:  55.6 [m]
Decay constant:  2.0778e-04 [1/s]
Daughters:  Cf-251 (100.0%)
Radioactive daughters:  Cf-251

Dosimetric constants

Mean alpha energy:  0.0 [MeV]
Mean electron energy:  0.36933 [MeV]
Mean photon energy:  0.0915 [MeV]
Air kerma rate constant, Γ10:  1.183e-17 [Gy·m2/Bq·s]
Air kerma coefficient, Kair:  1.183e-17 [Gy·m2/Bq·s]
Equilibrium dose constant for weakly-penetrating radiations (α and/or electrons), Δwp:  5.917e-14 [Gy·kg/Bq·s]
Equilibrium dose constant for alphas, Δα:  0.000e+00 [Gy·kg/Bq·s]
Equilibrium dose constant for betas/electrons, Δβ-,β+,e-:  5.917e-14 [Gy·kg/Bq·s]
Equilibrium dose constant for photons, Δp:  1.466e-14 [Gy·kg/Bq·s]

Dose point kernels (plot)

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/Bk-251 DPK.csv

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/Bk-251 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/Bk-251 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/Bk-251 Summary Spectrum.csv

 

Energy [MeV]

Yield [#/nt] if > 0.01

Radiation type

7.45444e-05

1.430e+01

X-ray

3.86326e-03

1.036e-01

X-ray

1.31965e-02

1.688e-02

X-ray

1.54368e-02

2.515e-02

X-ray

1.56809e-02

2.207e-01

X-ray

1.90028e-02

4.822e-02

X-ray

1.96961e-02

1.501e-02

X-ray

2.07498e-02

9.386e-02

X-ray

2.09431e-02

1.088e-02

X-ray

2.42553e-02

2.243e-02

X-ray

1.10388e-01

1.654e-01

X-ray

1.15701e-01

2.558e-01

X-ray

1.29279e-01

2.995e-02

X-ray

1.30000e-01

3.016e-02

Gamma

1.30526e-01

5.918e-02

X-ray

1.34357e-01

1.585e-02

X-ray

1.53000e-01

2.002e-02

Gamma

1.78000e-01

5.200e-02

Gamma

2.74244e-01

5.000e-02

Beta

2.86298e-01

9.000e-01

Beta

3.50494e-01

5.000e-02

Beta

1.14358e-04

3.903e+00

Auger electron

1.94555e-04

2.295e+00

Auger electron

2.11777e-04

1.794e-02

Auger electron

3.36988e-04

3.781e+00

Auger electron

6.73819e-04

7.839e-01

Auger electron

2.33599e-03

1.824e-01

Auger electron

2.79913e-03

1.165e+00

Auger electron

3.07200e-03

1.024e-02

Conversion electron

3.46683e-03

2.813e-01

Auger electron

4.23011e-03

1.834e-02

Auger electron

4.89500e-03

1.819e-01

Conversion electron

1.13083e-02

2.586e-01

Auger electron

1.52764e-02

1.386e-01

Auger electron

1.73700e-02

1.958e-01

Conversion electron

1.78972e-02

8.318e-02

Conversion electron

1.92769e-02

1.738e-02

Auger electron

1.97202e-02

1.492e-01

Conversion electron

2.25880e-02

3.218e-02

Conversion electron

2.30010e-02

3.108e-02

Conversion electron

2.48240e-02

5.519e-02

Conversion electron

2.79010e-02

2.556e-02

Conversion electron

2.83700e-02

2.504e-02

Conversion electron

4.23700e-02

3.311e-01

Conversion electron

4.27262e-02

1.684e-02

Conversion electron

1.03953e-01

8.742e-02

Conversion electron

1.04758e-01

1.018e-02

Conversion electron

1.24896e-01

2.418e-02

Conversion electron

1.26953e-01

3.632e-02

Conversion electron

1.47896e-01

1.005e-02

Conversion electron

1.51953e-01

6.124e-02

Conversion electron

1.72896e-01

1.694e-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

 

 

 

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