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Radionuclide Dosimetric Data Sheets

Neptunium-232

Summary data

General

Classification

Isotope:  Np-232
Atomic number (Z):  93
Mass number (A):  232
Neutron number (N):  139

Radioactive decay

Decay modes:  β+, Electron capture
Half-life:  14.7 [m]
Decay constant:  7.8588e-04 [1/s]
Daughters:  U-232 (100.0%)
Radioactive daughters:  U-232

Dosimetric constants

Mean alpha energy:  0.0 [MeV]
Mean electron energy:  0.10732 [MeV]
Mean photon energy:  1.19689 [MeV]
Air kerma rate constant, Γ10:  6.185e-17 [Gy·m2/Bq·s]
Air kerma coefficient, Kair:  6.189e-17 [Gy·m2/Bq·s]
Equilibrium dose constant for weakly-penetrating radiations (α and/or electrons), Δwp:  1.719e-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-:  1.719e-14 [Gy·kg/Bq·s]
Equilibrium dose constant for photons, Δp:  1.918e-13 [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/Np-232 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/Np-232 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/Np-232 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/Np-232 Summary Spectrum.csv

 

Energy [MeV]

Yield [#/nt] if > 0.01

Radiation type

7.54888e-05

2.175e+01

X-ray

3.25416e-03

1.327e-01

X-ray

1.16607e-02

2.101e-02

X-ray

1.34452e-02

3.424e-02

X-ray

1.36268e-02

3.008e-01

X-ray

1.64468e-02

6.308e-02

X-ray

1.65865e-02

1.083e-02

X-ray

1.70780e-02

1.193e-02

X-ray

1.73072e-02

2.354e-01

X-ray

2.02658e-02

5.331e-02

X-ray

2.09317e-02

1.032e-02

X-ray

9.50660e-02

2.422e-01

X-ray

9.89281e-02

3.875e-01

X-ray

1.08997e-01

1.523e-02

Gamma

1.10929e-01

4.468e-02

X-ray

1.11820e-01

8.738e-02

X-ray

1.14846e-01

1.117e-02

X-ray

1.15080e-01

2.260e-02

X-ray

2.23600e-01

2.236e-02

Gamma

2.82000e-01

1.976e-01

Gamma

3.27300e-01

5.200e-01

Gamma

3.77000e-01

1.248e-02

Gamma

7.55000e-01

4.212e-02

Gamma

8.14800e-01

4.108e-02

Gamma

8.19500e-01

3.328e-01

Gamma

8.64300e-01

2.028e-01

Gamma

8.67200e-01

2.444e-01

Gamma

9.41600e-01

1.612e-02

Gamma

1.03740e+00

3.276e-02

Gamma

1.12600e+00

1.456e-02

Gamma

7.21936e-05

5.861e+00

Auger electron

1.63006e-04

3.738e-02

Auger electron

1.85791e-04

5.739e+00

Auger electron

1.92311e-04

3.275e+00

Auger electron

5.37822e-04

8.453e-01

Auger electron

1.35608e-03

2.901e-01

Auger electron

2.43638e-03

1.897e+00

Auger electron

2.90698e-03

3.560e-01

Auger electron

3.52401e-03

2.093e-02

Auger electron

1.01662e-02

4.815e-01

Auger electron

1.34915e-02

2.447e-01

Auger electron

1.68500e-02

2.928e-02

Auger electron

2.65300e-02

2.776e-01

Conversion electron

3.03920e-02

2.414e-01

Conversion electron

4.32844e-02

1.463e-01

Conversion electron

4.75740e-02

5.146e-02

Conversion electron

7.54320e-02

1.669e-02

Auger electron

8.79530e-02

5.900e-02

Conversion electron

9.18150e-02

3.883e-02

Conversion electron

1.04707e-01

2.821e-02

Conversion electron

1.65890e-01

1.676e-02

Conversion electron

2.11190e-01

3.344e-02

Conversion electron

2.60956e-01

1.261e-02

Conversion electron

3.06256e-01

1.814e-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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