This category covers the fundamentals of radiation, including:
the different types of radiation, radiation quantities and units, basic terminology, radiation doses and dose calculations, etc.
The following health physics questions have been answered by an expert and approved by our editors for inclusion in our "Ask the Experts" feature. Click on the question to see the answer.
| Questions in this Category Are in the Following Subcategories: |
| • Alpha Radiation |
| • Beta Particles (negative and positive) and Electrons |
| • Doses and Dose Calculations |
| • Fission, Fusion |
| • Interaction Coefficients |
| • Neutrons |
| • Photons |
| • Radionuclides |
| • Radiation Quantities and Units |
| • Radiation Shielding |
| • Radiation Effects |
| • Miscellaneous |
| |
| Alpha Radiation |
| Q9290 |
– |
Surface contamination monitoring |
| Q9903 |
– |
Solubility of transuranics |
| Q10849 |
– |
Thorium in plants |
| Q11029 |
– |
U-238 in a cornerstone |
| Q12703 |
– |
Possible thorium poisoning |
| |
| Beta Particles (negative and positive) and Electrons |
| Q6240 |
– |
How do positron and electron ranges compare? |
| Q7770 |
– |
Is this beta radiation or bremsstrahlung from this strontium-90 source? |
| Q9260 |
– |
Where can I find tables of beta emitters by maximum beta energy? |
| Q9707 |
– |
Difference between mean range and max range |
| |
| Doses and Dose Calculations |
| Q4025 |
– |
Dose and properties of irradiated material |
| Q11233 |
– |
Calculation of dose from inhalation of thorium-232 |
| Q11413 |
– |
What tissue weighting factors should be applied to remainder tissues? |
| Q11416 |
– |
Is there a valid relationship between LET and RBE? |
| Q11931 |
– |
External whole-body counting vs. biological excreta measurements |
| Q12529 |
– |
Urine output value per day for internal dose calculation |
| Q12633 |
– |
Beta dose rates in air at various distances |
| Q12635 |
– |
Why are there differences between internal dose conversion factors for the public and workers? |
| Q12869 |
– |
Can a 50-y dose commitment be divided by 50 to give an annual rate? |
| Q12910 |
– |
Considerations in correlating thorium bioassay measurements with intakes |
| Q13633 |
– |
Lifetime dose limits for nonstochastic effects |
| Q13647 |
– |
Does the use of effective dose provide an accurate assessment of dose? |
| Q13818 |
– |
What is the dose from inhaled tritium gas leaked from this device? |
| Q13901 |
– |
How do I reconcile the external dose rate from this contaminated food with expected internal dose? |
| Q13910 |
– |
Will 100 million people gathered together all die from an eight-hour exposure to natural radiation? |
| |
| Fission, Fusion |
| Q10097 |
– |
Why are cesium-137, strontium-90, and iodine-131 the fission products that get most talked about when many more fission products are produced in reactors? |
| |
| Interaction Coefficients |
| Q8659 |
– |
Why does the attenuation coefficient change with field size? |
| |
| Neutrons |
| Q8192 |
– |
Neutron decay and residual activity from nuclear bomb |
| Q8216 |
– |
Am I receiving dose from this Pu-Be source? |
| Q8536 |
– |
How do I obtain neutron attenuation cross sections? |
| Q9869 |
– |
How do I calculate dose from this Pu-Be source? |
| Q12136 |
– |
Correlation of neutron dose rate with gamma dose rate from americium-241-Be source |
| Q12241 |
– |
What activation products might come from neutron irradiation? |
| Q12454 |
– |
Activation products from neutron therapy |
| Q13014 |
– |
Will neutron exposure during air flight activate the cobalt in my metallic implant? |
| |
| Photons |
| Q4817 |
– |
Average gamma energy of Ra-226 |
| Q7385 |
– |
Current gamma ray dose constants |
| Q9016 |
– |
Are these hard or soft x rays from this RF generator? |
| Q9118 |
– |
Does positron kinetic energy go to annihilation photons? |
| Q10388 |
– |
Are these very low energy photons really producing this notable increase in exposure rate? |
| Q10579 |
– |
How do these multiple x-ray energies originate? |
| Q11545 |
– |
Why don't I get expected results using the Rad Pro Calculator? |
| Q11989 |
– |
Is the gamma-ray dose-rate constant defined for water, and how does one account for attenuation? |
| Q12285 |
– |
Factors affecting observed Compton scatter in materials |
| |
| Radionuclides |
| Q8270 |
– |
How does one obtain the half-life for long-lived radionuclides? |
| Q8820 |
– |
How can activity increase with radioactive decay? |
| Q9852 |
– |
Exposure from technetium-99 |
| Q11530 |
– |
Beta and gamma emissions from 232Th progeny decay |
| Q11727 |
– |
Products for cleaning up radioactive iodine |
| Q12732 |
– |
Zirconium 95 clearance classes |
| |
| Radiation Quantities and Units |
| Q7868 |
– |
Is effective dose a practical quantity in operational health physics? |
| Q10010 |
– |
Why is the term stopping power being used for photons? |
| Q11309 |
– |
Is it REM or rem? |
| Q11491 |
– |
How may I adjust ICRP Publication 72 dose conversion factors for insoluble plutonium oxide? |
| Q12078 |
– |
Differences between ambient dose equivalent and equivalent dose |
| Q12211 |
– |
Can Hp(10) be used to approximate the eye lens dose? |
| Q12522 |
– |
How does kerma differ from absorbed dose? |
| Q12600 |
– |
Free-in-air karma measurement |
| |
| Radiation Shielding |
| Q8135 |
– |
How do I determine HVL for brass? |
| Q8929 |
– |
Depleted uranium as shielding |
| Q9724 |
– |
What boron-based buffer is available for neutron shielding? |
| Q11377 |
– |
Characteristic x rays from interactions in leaded gloves |
| Q11704 |
– |
Could an old lead pig be contaminated? |
| Q12133 |
– |
Neutron dose through shield penetrations |
| Q13036 |
– |
Why are high mass, high atomic number materials used for shielding even though the mass attenuation coefficients are smaller for high atomic number than for low atomic number materials? |
| Q13068 |
– |
Attenuation of beta radiation in protective eyewear |
| Q14101 |
– |
Polyethylene shield for neutrons |
| |
| Radiation Effects |
| Q10942 |
– |
Radiation sensitivity of women vs. men |
| Q11569 |
– |
Risks from Carbon-11 |
| Q12014 |
– |
Fate of radiation after it interacts with shielding material |
| Q13187 |
– |
Indirect radiation effects and indirectly ionizing radiation |
| Q13412 |
– |
Radiation effects on metals |
| |
| Miscellaneous |
| Q7283 |
– |
How do I interpret these radon concentration numbers from early hot springs measurements? |
| Q7434 |
– |
Radionuclide abundance, branching fraction, and radiation yield |
| Q7462 |
– |
Why liquid, solid, or gaseous targets for cyclotron radionuclide production? |
| Q7613 |
– |
X-ray energy deposited, energy fluence, and dose in silicon |
| Q7843 |
– |
Alterations of a radionuclide's half-life |
| Q7878 |
– |
Convert mass concentration in soil to area concentration |
| Q8186 |
– |
Radiation terms |
| Q8340 |
– |
How much dose might I be getting from this x-ray diffraction unit? |
| Q8344 |
– |
What is the effect of kVp on x-ray intensity? |
| Q8353 |
– |
Preparation of aqueous radionuclide standard |
| Q8542 |
– |
When and why are high doses expressed as absorbed doses? |
| Q8671 |
– |
Are these GM readings from uranium metal realistic? |
| Q8724 |
– |
What is the effective atomic number of glass fiber filter? |
| Q8966 |
– |
What weighting factor is used in converting organ dose to effective dose? |
| Q8974 |
– |
Health physics concerns with nanoparticles |
| Q9281 |
– |
How long before radium reaches equilibrium with uranium in plant leaves? |
| Q9291 |
– |
Is this well water with uranium safe to drink? |
| Q9399 |
– |
Ionization from lightning, Tesla coils, gamma rays, and x rays |
| Q9434 |
– |
Why are photons and neutrons described as indirectly ionizing? |
| Q9498 |
– |
Methods to track transport of particles in the environment and in the body |
| Q9503 |
– |
Is it appropriate to project cancer risk for background exposure? |
| Q9635 |
– |
What is the source of the gamma emission from this Po-210 source? |
| Q9646 |
– |
Why is energy released in decay so important? |
| Q9658 |
– |
How much ionization would this gamma ray yield in a cell? |
| Q9678 |
– |
Do levels of radioactivity in the United States follow the levels being released from the Japanese reactor site? |
| Q9715 |
– |
Should I be concerned with rain water contaminated with Fukushima radioactivity? |
| Q9723 |
– |
What is the concrete TVL for thallium-201? |
| Q9776 |
– |
Are radioactive lightning rods a potential contamination hazard? |
| Q9782 |
– |
Explain why adult and child doses from CT scans differ |
| Q9800 |
– |
Why does NRPB ImPact software require NRPB SR-250 organ dose data? |
| Q9828 |
– |
How to determine dimensions or shielding for storage room for Troxler gauges. |
| Q9832 |
– |
How do I evaluate risks from inhalation exposures? |
| Q9866 |
– |
Why do we use both distance and attenuation to calculate reduction in photon dose rate? |
| Q9921 |
– |
What are the requirements for using the radiation warning symbol? |
| Q10176 |
– |
Are knock-on ions produced by radiation interactions a hazard? |
| Q10341 |
– |
What is the significance of half-life in radiation control? |
| Q10370 |
– |
How much of a lead equivalent is 3/8-inch tempered glass? |
| Q10372 |
– |
How should I evaluate natural radionuclides in water, and how do I determine doses from exposures?” |
| Q10396 |
– |
Is stainless steel acceptable for this laboratory sink? |
| Q10438 |
– |
Concern with radium plateout on walls of water cleanup pressure vessel |
| Q10463 |
– |
Release of iodine from charcoal cleanup systems |
| Q10781 |
– |
Are skin dose and eye dose part of effective dose? |
| Q10795 |
– |
Can we transform these radioactive atoms to stable atoms? |
| Q10976 |
– |
How long a line segment should I select to simulate a very long line source? |
| Q11321 |
– |
Concern with exposure from this Cs-137/Ba-137m generator |
| Q11517 |
– |
Can I use dose to calculate activity? |
| Q11547 |
– |
Determining secular equilibrium in radium-226 sample |
| Q11637 |
– |
Effect of diseases on organ radioactivity |
| Q12008 |
– |
Can electricity deactivate radioactive atoms? |
| Q12012 |
– |
What is the fate of alpha particles and beta particles after they are emitted by nuclei? |
| Q12291 |
– |
Calculating TEDE/CEDE from exposure to tritiated water |
| Q12299 |
– |
Leakage x rays from electron microscopes |
| Q12357 |
– |
Does the amount of radioactivity in a human stay constant during a life span? |
| Q12404 |
– |
Radionuclide retention and clearance |
| Q12413 |
– |
How can I convert environmental equivalent dose rate H*(10) (mSv/hr) to effective dose rate (mSv/hr)? |
| Q12659 |
– |
Fukushima fallout |
| Q12800 |
– |
What is an appropriate gamma ray dose rate constant for radium? |
| Q12845 |
– |
What fraction of electron energy is converted into bremsstrahlung? |
| Q12968 |
– |
Does radiation exposure cause objects to become radioactive? |
| Q13002 |
– |
How do I show no x rays are coming from this 70-80 GHz body scanner? |
| Q13119 |
– |
Using radiation from radioactivity in waste sites to generate electricity |
| Q13183 |
– |
What are biological half-lives for lead and radium? |
| Q13223 |
– |
Why are acute doses characterized in grays rather than sieverts? |
| Q13249 |
– |
Understanding tritium bioassay results |
| Q13388 |
– |
Can you eliminate man-made radiation exposure? |
| Q13419 |
– |
How should I evaluate dose rate from sulfur-35? |
| Q13456 |
– |
Spontaneous fission of natural uranium in everyday objects |
| Q13504 |
– |
Why don't the effective dose conversion factors in ICRP 116 have any assigned uncertainties? |
| Q13807 |
– |
How can we justify using water as a replacement for tissue in dosimetry applications? |
| Q14107 |
– |
Decay correcting a mock 131-I source |
| Q14246 |
– |
Dependence of ICRP committed dose coefficients on intake and f1 values |
| Q14414 |
– |
Protection factors and gamma attenuation following an atomic weapon explosion |
| Q14423 |
– |
Protection factors and gamma attenuation following an atomic weapon explosion |
