Absorbed Dose Constants

The "Absorbed Dose Constant" gives absorbed dose rates per unit of accumulated radioactivity. These constants are useful for assessing the energy deposited in an infinite, homogeneous medium in which radioactivity is uniformly distributed. A good example is in assessing the absorbed dose in an individual organs after uptake of a radiopharmaceutical. These constants have broad applicability for radiation protection. The following is a listing of Absorbed Dose Constants for a variety of radionuclides, given in units of gram-rad (g-rad) per microcurie-hour (uCi/hr). Absorbed Dose Constants are specific to the type and energy of the radiation emitted during the decay of the radionuclide. Therefore, each entry gives the radionuclide symbol (i.e., I-131), followed by the radiation type (alpha, beta [average], total beta, x-ray or gamma), the radiation energy (in units of MeV), and ending with the Absorbed Dose Constant.

Actinium

Ac-228 - total beta - 0.375 - 0.778

Aluminum

Al-28 - beta - 1.242 - 2.650
Al-28 - gamma - 1.778 - 3.790

Americium

Am-241 - alpha - 5.485 - 9.960
Am-241 - gamma - 0.059 - 0.046

Barium

Ba-133 - gamma - 0.383 - 0.070
Ba-137 - gamma - 0.662 - 1.270
Ba-140 - btotal beta - 0.272 - 0.578

Beryllium

Be-7 - beta - 0.477 - 0.106
Be-10 - beta - 0.202 - 0.431

Bismuth

Bi-210 - beta - 0.389 - 0.829
Bi-212 - alpha - 6.050 - 3.250
Bi-214 - total beta - 0.632 - 1.350

Bromine

Br-80 - total beta - 0.783 - 1.530
Br-82 - gamma - 0.554 - 0.833
Br-82 - total beta - 0.137 - 0.290

Cadmium

Cd-109 - x-ray - 0.022 - 0.016
Cd-111 - gamma - 0.245 - 0.491

Calcium

Ca-45 - beta - 0.077 - 0.164
Ca-47 - total beta - 0.345 - 0.733
Ca-49 - total beta - 0.872 - 1.860
Ca-49 - gamma - 3.084 - 6.050

Californium

Cf-249 - gamma - 0.387 - 0.545
Cf-250 - alpha - 6.030 - 10.720
Cf-252 - alpha - 6.118 - 10.630

Carbon

C-11 - beta - 0.385 - 0.819
C-14 - beta - 0.049 - 0.105

Cerium

Ce-141 - total beta - 0.144 - 0.308
Ce-144 - total beta - 0.082 - 0.177

Chlorine

Cl-36 - beta - 0.251 - 0.530

Chromium

Cr-49 - gamma - 0.090 - 0.103
Cr-49 - total beta - 0.644 - 1.260
Cr-51 - gamma - 0.320 - 0.067

Cesium

Cs-134 - total beta - 0.156 - 0.334
Cs-134 - gamma - 0.795 - 1.450
Cs-134 - gamma - 0.604 - 1.260
Cs-136 - total beta - 0.100 - 0.213
Cs-136 - gamma - 0.818 - 1.740
Cs-137 - total beta - 0.170 - 0.364

Cobalt

Co-56 - total beta - 0.607 - 0.256
Co-56 - gamma - 0.846 - 1.800
Co-57 - gamma - 0.122 - 0.222
Co-58 - gamma - 0.810 - 1.720
Co-60 - gamma - 1.173 - 2.500
Co-60 - beta - 0.095 - 0.204
Co-60 - gamma - 1.332 - 2.840

Copper

Cu-64 - beta - 0.278 - 0.106
Cu-64 - beta - 0.190 - 0.151

Curium

Cm-242 - alpha - 6.122 - 9.650
Cm-244 - alpha - 5.804 - 9.450

Europium

Eu-143 - total beta - 0.255 - 0.480
Eu-152 - total beta - 0.300 - 0.178

Fluorine

F-18 - beta - 0.249 - 0.515

Gallium

Ga-66 - total beta - 1.739 - 2.050
Ga-67 - gamma - 0.093 - 0.071
Ga-68 - gamma - 1.039 - 0.859
Ga-69 - total beta - 0.829 - 1.570

Germanium

Ge-77 - total beta - 0.646 - 1.370
Ge-77 - gamma - 0.264 - 0.300

Gold

Au-198 - total beta - 0.311 - 0.664
Au-198 - gamma - 0.411 - 0.838

Hydrogen

H-3 - beta - 0.005 - 0.012

Indium

In-111 - gamma - 0.245 - 0.491
In-111 - gamma - 0.171 - 0.329

Iodine

I-122 - total beta - 1.363 - 2.210
I-123 - gamma - 0.159 - 0.282
I-124 - total beta - 0.831 - 0.412
I-125 - gamma - 0.035 - 0.005
I-126 - total beta - 0.459 - 0.010
I-129 - beta - 0.041 - 0.087
I-129 - gamma - 0.039 - 0.006
I-131 - total beta - 0.181 - 0.387
I-131 - gamma - 0.364 - 0.630
I-133 - total beta - 0.407 - 0.867
I-133 - gamma - 0.529 - 0.974

Iridium

Ir-192 - gamma - 0.316 - 0.559
Ir-192 - total beta - 0.180 - 0.368

Iron

Fe-55 - x-ray - 0.005 - 0.002
Fe-59 - gamma - 1.291 - 1.190
Fe-59 - total beta - 0.117 - 0.250
Fe-59 - gamma - 1.099 - 1.320

Krypton

Kr-79 - total beta - 0.262 - 0.039
Kr-81 - gamma - 0.276 - 0.021
Kr-85 - gamma - 0.151 - 0.242
Kr-85 - total beta - 0.251 - 0.534
Kr-85 - gamma - 0.513 - 0.005
Kr-87 - gamma - 0.402 - 0.424
Kr-87 - total beta - 1.324 - 2.820
Kr-88 - total beta - 0.359 - 0.766
Kr-90 - total beta - 1.317 - 2.780

Lead

Pb-210 - total beta - 0.006 - 0.014
Pb-214 - total beta - 0.219 - 0.468

Manganese

Mn-52 - beta - 0.241 - 0.151
Mn-52 - gamma - 0.744 - 1.430
Mn-52 - gamma - 0.935 - 1.880
Mn-54 - gamma - 0.834 - 1.780
Mn-56 - gamma - 0.846 - 1.780
Mn-56 - total beta - 0.829 - 1.770
Mn-57 - total beta - 1.101 - 2.340

Molybdinum

Mo-91 - total beta - 1.549 - 3.100
Mo-99 - total beta - 0.386 - 0.838

Neptunium

Np-238 - total beta - 0.223 - 0.479

Nickel

Ni-56 - gamma - 0.158 - 0.333
Ni-57 - total beta - 0.345 - 0.295
Ni-57 - gamma - 1.377 - 2.290
Ni-65 - gamma - 1.623 - 0.742
Ni-65 - total beta - 0.632 - 1.350

Niobium

Nb-92 - gamma - 0.934 - 1.970
Nb-95 - beta - 0.043 - 0.092
Nb-95 - gamma - 0.765 - 1.630
Nb-96 - gamma - 0.778 - 1.600
Nb-96 - total beta - 0.248 - 0.530
Nb-97 - total beta - 0.466 - 0.993
Nb-97 - gamma - 0.657 - 1.370

Nitrogen

N-13 - beta - 0.491 - 1.050
N-16 - gamma - 6.129 - 9.010
N-16 - total beta - 2.695 - 5.740

Oxygen

O-15 - beta - 0.735 - 1.560

Phosphorus

P-32 - beta - 0.694 - 1.480
P-33 - beta - 0.076 - 0.163

Plutonium

Pu-238 - alpha - 5.499 - 8.390
Pu-239 - alpha - 5.155 - 8.050
Pu-240 - alpha - 5.168 - 8.090
Pu-242 - alpha - 4.900 - 8.140
Pu-244 - alpha - 4.589 - 7.870

Polonium

Po-210 - alpha - 5.304 - 11.300
Po-212 - alpha - 8.784 - 18.700
Po-214 - alpha - 7.687 - 16.370

Potassium

K-40 - beta - 0.508 - 0.968
K-42 - beta - 1.563 - 2.730
K-42 - beta - 0.298 - 0.585
K-43 - gamma - 0.617 - 1.060
K-43 - gamma - 0.372 - 0.693

Radium

Ra-224 - alpha - 5.685 - 11.520
Ra-226 - alpha - 4.785 - 9.630
Ra-226 - gamma - 0.186 - 0.013
Ra-228 - beta - 0.009 - 0.021

Radon

Rn-220 - alpha - 6.288 - 13.380
Rn-222 - alpha - 5.489 - 11.680

Selenium

Se-73 - total beta - 0.563 - 0.790
Se-75 - gamma - 0.136 - 0.171

Silicon

Si-31 - beta - 0.595 - 1.270
Si-32 - beta - 0.065 - 0.138

Silver

Ag-110 - total beta - 0.067 - 0.140
Ag-110 - gamma - 0.657 - 1.320
Ag-111 - total beta - 0.349 - 0.745

Sodium

Na-22 - beta - 0.215 - 0.412
Na-22 - gamma - 1.274 - 2.710
Na-24 - gamma - 1.368 - 2.910
Na-24 - beta - 0.553 - 1.180
Na-24 - gamma - 2.754 - 5.860

Strontium

Sr-85 - gamma - 0.513 - 1.090
Sr-85 - gamma - 0.231 - 0.418
Sr-89 - beta - 0.583 - 1.240
Sr-90 - beta - 0.196 - 0.417
Sr-91 - total beta - 0.658 - 1.390

Sulfur

S-35 - beta - 0.048 - 0.104

Technetium

Tc-95 - total beta - 0.290 - 0.003
Tc-97 - total beta - 0.696 - 1.490
Tc-99 - gamma - 0.140 - 0.267
Tc-99 - beta - 0.085 - 0.180

Thallium

Tl-202 - gamma - 0.439 - 0.857
Tl-204 - beta - 0.243 - 0.506
Tl-208 - gamma - 2.614 - 5.560
Tl-208 - total beta - 0.559 - 1.180
Tl-208 - gamma - 0.583 - 1.050

Thorium

Th-228 - alpha - 5.423 - 8.400
Th-228 - alpha - 5.340 - 3.040
Th-230 - alpha - 4.687 - 7.620
Th-232 - alpha - 4.010 - 6.580
Th-232 - alpha - 3.953 - 1.940
Th-234 - total beta - 0.044 - 0.092

Uranium

U-230 - alpha - 5.817 - 3.970
U-230 - alpha - 5.888 - 8.450
U-233 - alpha - 4.824 - 8.670
U-234 - alpha - 4.775 - 7.360
U-235 - gamma - 0.184 - 0.211
U-235 - alpha - 4.396 - 5.150
U-238 - alpha - 4.196 - 6.880
U-238 - alpha - 4.147 - 2.030

Xenon

Xe-133 - total beta - 0.100 - 0.214

Ytrium

Y-88 - beta - 0.355 - 0.002
Y-88 - gamma - 1.836 - 3.890
Y-90 - gamma - 0.202 - 0.417
Y-90 - gamma - 0.479 - 0.929
Y-90 - beta - 0.934 - 1.990
Y-91 - total beta - 0.602 - 1.280

Zinc

Zn-62 - beta - 0.258 - 0.042
Zn-65 - beta - 0.143 - 0.004
Zn-65 - gamma - 1.115 - 1.210
Zn-69 - gamma - 0.438 - 0.887
Zn-69 - tbeta - 0.321 - 0.684

Zirconium

Zr-88 - gamma - 0.392 - 0.814
Zr-89 - total beta - 1.360 - 2.900
Zr-89 - gamma - 0.909 - 1.920

**Listing partially extracted from DOE/TIC-11026, "Radioactive Decay Data Tables", 1981

IEM - Consulting and Services for Today's Business Climate