Beta Dose Rates in rad/hr per mCiMeV 1 cm 10 cm 30 cm 60 cm 90 cm 1.0 m0.15 1,200 1.7 0 0 0 00.25 1,000 2.2 0.1 0 0 00.30 900 3.6 0.1 0 0 00.50 750 5.2 0.4 0.05 0.01 00.75 650 5.0 0.5 0.05 0.01 01.0 550 4.6 0.4 0.1 0 01.25 450 4.3 0.4 0.1 0.04 0.021.50 400 4.0 0.4 0.1 0.04 0.021.75 350 3.4 0.4 0.1 0.04 0.022.00 340 3.6 0.4 0.1 0.04 0.022.25 320 3.3 0.4 0.1 0.04 0.02Beta dose should be treated as a “shallow” dose and shouldnot be summed with “deep” doses. This chart should also beused to determine beta+ doses from positron emitters.Half-value Thickness vs Beta EnergyIsotope Emax (MeV) Half-Value Thickness mg / cm 2C-14 0.156 2Tc-99 0.292 7.5Cl-36 0.714 15Sr/Y-90 0.546 / 2.284 150U-238 Betas from short lived progeny0.191 / 2.281 130P-32 1.710 150Estimate the half-value thickness for a beta emitter.mg/cm 2 = 50 x E 2where E is Emax in MeV for the beta emitterThis equation tends to underestimate the half-valuethickness for low energy betas and overestimate thehalf-value thickness for high energy betas.Beta Dose Rates in rad/hr per mCiMeV 1 cm 10 cm 30 cm 60 cm 90 cm 1.0 m0.15 1,200 1.7 0 0 0 00.25 1,000 2.2 0.1 0 0 00.30 900 3.6 0.1 0 0 00.50 750 5.2 0.4 0.05 0.01 00.75 650 5.0 0.5 0.05 0.01 01.0 550 4.6 0.4 0.1 0 01.25 450 4.3 0.4 0.1 0.04 0.021.50 400 4.0 0.4 0.1 0.04 0.021.75 350 3.4 0.4 0.1 0.04 0.022.00 340 3.6 0.4 0.1 0.04 0.022.25 320 3.3 0.4 0.1 0.04 0.02Beta dose should be treated as a “shallow” dose and shouldnot be summed with “deep” doses. This chart should also beused to determine beta+ doses from positron emitters.Half-value Thickness vs Beta EnergyIsotope Emax (MeV) Half-Value Thickness mg / cm 2C-14 0.156 2Tc-99 0.292 7.5Cl-36 0.714 15Sr/Y-90 0.546 / 2.284 150U-238 Betas from short lived progeny0.191 / 2.281 130P-32 1.710 150Estimate the half-value thickness for a beta emitter.mg/cm 2 = 50 x E 2where E is Emax in MeV for the beta emitterThis equation tends to underestimate the half-valuethickness for low energy betas and overestimate thehalf-value thickness for high energy betas.Beta Dose Rates in rad/hr per mCiMeV 1 cm 10 cm 30 cm 60 cm 90 cm 1.0 m0.15 1,200 1.7 0 0 0 00.25 1,000 2.2 0.1 0 0 00.30 900 3.6 0.1 0 0 00.50 750 5.2 0.4 0.05 0.01 00.75 650 5.0 0.5 0.05 0.01 01.0 550 4.6 0.4 0.1 0 01.25 450 4.3 0.4 0.1 0.04 0.021.50 400 4.0 0.4 0.1 0.04 0.021.75 350 3.4 0.4 0.1 0.04 0.022.00 340 3.6 0.4 0.1 0.04 0.022.25 320 3.3 0.4 0.1 0.04 0.02Beta dose should be treated as a “shallow” dose and shouldnot be summed with “deep” doses. This chart should also beused to determine beta+ doses from positron emitters.Half-value Thickness vs Beta EnergyIsotope Emax (MeV) Half-Value Thickness mg / cm 2C-14 0.156 2Tc-99 0.292 7.5Cl-36 0.714 15Sr/Y-90 0.546 / 2.284 150U-238 Betas from short lived progeny0.191 / 2.281 130P-32 1.710 150Estimate the half-value thickness for a beta emitter.mg/cm 2 = 50 x E 2where E is Emax in MeV for the beta emitterThis equation tends to underestimate the half-valuethickness for low energy betas and overestimate thehalf-value thickness for high energy betas.Beta Dose Rates in rad/hr per mCiMeV 1 cm 10 cm 30 cm 60 cm 90 cm 1.0 m0.15 1,200 1.7 0 0 0 00.25 1,000 2.2 0.1 0 0 00.30 900 3.6 0.1 0 0 00.50 750 5.2 0.4 0.05 0.01 00.75 650 5.0 0.5 0.05 0.01 01.0 550 4.6 0.4 0.1 0 01.25 450 4.3 0.4 0.1 0.04 0.021.50 400 4.0 0.4 0.1 0.04 0.021.75 350 3.4 0.4 0.1 0.04 0.022.00 340 3.6 0.4 0.1 0.04 0.022.25 320 3.3 0.4 0.1 0.04 0.02Beta dose should be treated as a “shallow” dose and shouldnot be summed with “deep” doses. This chart should also beused to determine beta+ doses from positron emitters.Half-value Thickness vs Beta EnergyIsotope Emax (MeV) Half-Value Thickness mg / cm 2C-14 0.156 2Tc-99 0.292 7.5Cl-36 0.714 15Sr/Y-90 0.546 / 2.284 150U-238 Betas from short lived progeny0.191 / 2.281 130P-32 1.710 150Estimate the half-value thickness for a beta emitter.mg/cm 2 = 50 x E 2where E is Emax in MeV for the beta emitterThis equation tends to underestimate the half-valuethickness for low energy betas and overestimate thehalf-value thickness for high energy betas.
Positron Emitters Beta+ Energy and % AbundanceHalf-life MeV (%)C-11 20.3 m 0.960 (99.8%)N-13 9.97 m 1.199 (99.8%)O-15 122 s 1.732 (99.9%)F-18 1.83 h 0.634 (96.7%)Na-22 2.605 y 0.546 (89.8%)Al-26 7.3E5 y 3.210 (100%)V-48 15.98 d 0.697 (50.1%)Mn-52 5.591 d 2.633 (94.9%)Co-56 77.3 d 1.458 (19.0%)Ni-57 35.6 h 0.737 (7.0%), 0.865 (35.3%)Co-58 70.88 d 0.475 (14.9%)Cu-62 9.74 m 2.926 (97.2%)Zn-65 243.8 d 0.330 (1.4%)Ga-68 67.7 m 0.822 (1.2%), 1.899 (89.1%)As-74 17.8 d 0.945 (26.1%), 1.540 (3.0%)Rb-82 1.26 m 2.601 (13.1%), 3.378 (81.8%)Several of the positron emitters are useful in PET studies.That usefulness is somewhat offset by the cost of producingthe radionuclides and the added complexity of radiationprotection. For all of the positron emitters the energy of theBeta+ must be considered. Refer to the table of Beta DoseRates for estimates of beta+ radiation exposure. Also,consider the annihilation photons when the positron comesinto contact with a beta-, annihilating their masses andproducing two 511 KeV photons. These photons present anexternal radiation hazard. For the patient undergoing a PETscan the combination of the positron energy and the photonenergy must be considered.33Positron Emitters Beta+ Energy and % AbundanceHalf-life MeV (%)C-11 20.3 m 0.960 (99.8%)N-13 9.97 m 1.199 (99.8%)O-15 122 s 1.732 (99.9%)F-18 1.83 h 0.634 (96.7%)Na-22 2.605 y 0.546 (89.8%)Al-26 7.3E5 y 3.210 (100%)V-48 15.98 d 0.697 (50.1%)Mn-52 5.591 d 2.633 (94.9%)Co-56 77.3 d 1.458 (19.0%)Ni-57 35.6 h 0.737 (7.0%), 0.865 (35.3%)Co-58 70.88 d 0.475 (14.9%)Cu-62 9.74 m 2.926 (97.2%)Zn-65 243.8 d 0.330 (1.4%)Ga-68 67.7 m 0.822 (1.2%), 1.899 (89.1%)As-74 17.8 d 0.945 (26.1%), 1.540 (3.0%)Rb-82 1.26 m 2.601 (13.1%), 3.378 (81.8%)Several of the positron emitters are useful in PET studies.That usefulness is somewhat offset by the cost of producingthe radionuclides and the added complexity of radiationprotection. For all of the positron emitters the energy of theBeta+ must be considered. Refer to the table of Beta DoseRates for estimates of beta+ radiation exposure. Also,consider the annihilation photons when the positron comesinto contact with a beta-, annihilating their masses andproducing two 511 KeV photons. These photons present anexternal radiation hazard. For the patient undergoing a PETscan the combination of the positron energy and the photonenergy must be considered.33Positron Emitters Beta+ Energy and % AbundanceHalf-life MeV (%)C-11 20.3 m 0.960 (99.8%)N-13 9.97 m 1.199 (99.8%)O-15 122 s 1.732 (99.9%)F-18 1.83 h 0.634 (96.7%)Na-22 2.605 y 0.546 (89.8%)Al-26 7.3E5 y 3.210 (100%)V-48 15.98 d 0.697 (50.1%)Mn-52 5.591 d 2.633 (94.9%)Co-56 77.3 d 1.458 (19.0%)Ni-57 35.6 h 0.737 (7.0%), 0.865 (35.3%)Co-58 70.88 d 0.475 (14.9%)Cu-62 9.74 m 2.926 (97.2%)Zn-65 243.8 d 0.330 (1.4%)Ga-68 67.7 m 0.822 (1.2%), 1.899 (89.1%)As-74 17.8 d 0.945 (26.1%), 1.540 (3.0%)Rb-82 1.26 m 2.601 (13.1%), 3.378 (81.8%)Several of the positron emitters are useful in PET studies.That usefulness is somewhat offset by the cost of producingthe radionuclides and the added complexity of radiationprotection. For all of the positron emitters the energy of theBeta+ must be considered. Refer to the table of Beta DoseRates for estimates of beta+ radiation exposure. Also,consider the annihilation photons when the positron comesinto contact with a beta-, annihilating their masses andproducing two 511 KeV photons. These photons present anexternal radiation hazard. For the patient undergoing a PETscan the combination of the positron energy and the photonenergy must be considered.33Positron Emitters Beta+ Energy and % AbundanceHalf-life MeV (%)C-11 20.3 m 0.960 (99.8%)N-13 9.97 m 1.199 (99.8%)O-15 122 s 1.732 (99.9%)F-18 1.83 h 0.634 (96.7%)Na-22 2.605 y 0.546 (89.8%)Al-26 7.3E5 y 3.210 (100%)V-48 15.98 d 0.697 (50.1%)Mn-52 5.591 d 2.633 (94.9%)Co-56 77.3 d 1.458 (19.0%)Ni-57 35.6 h 0.737 (7.0%), 0.865 (35.3%)Co-58 70.88 d 0.475 (14.9%)Cu-62 9.74 m 2.926 (97.2%)Zn-65 243.8 d 0.330 (1.4%)Ga-68 67.7 m 0.822 (1.2%), 1.899 (89.1%)As-74 17.8 d 0.945 (26.1%), 1.540 (3.0%)Rb-82 1.26 m 2.601 (13.1%), 3.378 (81.8%)Several of the positron emitters are useful in PET studies.That usefulness is somewhat offset by the cost of producingthe radionuclides and the added complexity of radiationprotection. For all of the positron emitters the energy of theBeta+ must be considered. Refer to the table of Beta DoseRates for estimates of beta+ radiation exposure. Also,consider the annihilation photons when the positron comesinto contact with a beta-, annihilating their masses andproducing two 511 KeV photons. These photons present anexternal radiation hazard. For the patient undergoing a PETscan the combination of the positron energy and the photonenergy must be considered.33