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