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:
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| • Alpha Radiation |
| • Beta Particles (negative and positive) and Electrons |
| • Binding Energies |
| • Elements |
| • Fission, Fusion |
| • Interaction Coefficients |
| • Neutrons |
| • Photons |
| • Radionuclides |
| • Radiation Quantities and Units |
| • Radiation Shielding |
• Secular Equilibrium
|
| • Miscellaneous |
| |
Alpha Radiation
|
| Q2313 |
– |
Alpha particles absorbed by paper |
| Q5227 |
– |
Why alpha decay but no neutron emission? |
| |
Beta Particles (negative and positive) and Electrons
|
| Q161 |
– |
I need information on the use of a depleted uranium slab to calibrate beta detectors. |
| Q843 |
– |
Origins of Beta-minus particles and beta-plus particles (positrons) |
| Q1056 |
– |
Auger emitters |
| Q1259 |
– |
Positron emission |
| Q1646 |
– |
Urinalysis for beta emitters |
| Q2376 |
– |
Photons with beta decay |
| Q3549 |
– |
Beta quality factor |
| Q4307 |
– |
Calculate activity of beta emitter from exposure rate measurements |
| Q4510 |
– |
"Weak" and "soft" emitters |
| Q4616 |
– |
Range of beta particle |
| Q5992 |
– |
Integrating Beta Spectral Data |
| Q6240 |
– |
How do positron and electron ranges compare? |
| Q6463 |
– |
What happens to beta radiation in a magnetic field? |
| 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 |
| |
Binding Energies
|
| Q1240 |
– |
Q-value for hydrogen-2 reaction |
| Q1397 |
– |
Binding energy |
| |
Elements
|
| Q1295 |
– |
Elements that are solids |
| Q1554 |
– |
Naturally occurring elements |
| Q1630 |
– |
Synthetic elements |
| Q2994 |
– |
Last naturally occurring element |
| |
Fission, Fusion
|
| Q1629 |
– |
Fissionable materials |
| Q1655 |
– |
Hydrogen bombs |
| Q1935 |
– |
Fission and fusion |
| Q6333 |
– |
Characteristics of neutrons and gamma rays from spontaneous fission of californium-252. |
| 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
|
| Q1074 |
– |
Absorption coefficients |
| Q1239 |
– |
Cross section reaction |
| Q1632 |
– |
Mass attenuation coefficient |
| Q1978 |
– |
Radiation interaction and ultimate fate |
| Q2026 |
– |
Mass attenuation coefficient for lead |
| Q3890 |
– |
Linear attenuation coefficient of cinder blocks |
| Q3894 |
– |
Water (or seawater) to shield against cesium-137 |
| Q4080 |
– |
Energy dependence of linear attenuation coefficient |
| Q5721 |
– |
Why does HVL for uranium change abruptly as energy changes? |
| Q8659 |
– |
Why does the attenuation coefficient change with field size? |
| |
Neutrons
|
| Q283 |
– |
Interactions of fast neutrons in steel |
| Q311 |
– |
Why do moderated neutron spectra have a characteristic 1/E shape? |
| Q457 |
– |
Thermal neutron source |
| Q609 |
– |
Neutron radiation |
| Q618 |
– |
Spectrum from neutron sources |
| Q2095 |
– |
Portable source of thermal neutrons |
| Q2775 |
– |
Energy deposited in human tissue |
| Q2877 |
– |
Neutron radiation around nuclear reactors |
| Q3504 |
– |
Calibration with AmBe source |
| Q6847 |
– |
How do I calculate the dose rate from a Ra-Be source? |
| 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?” |
| |
Photons
|
| Q598 |
– |
Gamma rays vs. x rays |
| Q638 |
– |
Do x rays stay in the body? |
| Q784 |
– |
Gamma ray interactions |
| Q1351 |
– |
Photoelectric absorption |
| Q1745 |
– |
X radiation vs. UV radiation |
| Q2135 |
– |
Radioactive decay—gamma transitions |
| Q2357 |
– |
Energy range of medical x rays |
| Q4428 |
– |
Activity and gamma emissions |
| Q4817 |
– |
Average gamma energy of Ra-226 |
| Q4853 |
– |
Convert gamma rays to electricity |
| Q4920 |
– |
X-ray spectrum |
| Q4981 |
– |
Dose and fluence rate from cylindrical volume source |
| Q5537 |
– |
Reduce Photon Energy by Compton Scatter |
| Q6434 |
– |
What gamma rays should I expect from Am:Be and Pu:Be neutron sources? |
| 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? |
| |
Radionuclides
|
| Q43 |
– |
I am looking for a radioactive decay chain spreadsheet. |
| Q219 |
– |
How is strontium-90 produced and used? |
| Q250 |
– |
I need a manual which lists radionuclides by half-lives, energies, and source types. |
| Q449 |
– |
Thermal output of cobalt-60 |
| Q465 |
– |
Where do I buy isotopes? |
| Q731 |
– |
Convert activity concentration to atom or mass concentration |
| Q1139 |
– |
Is sulfur-34 radioactive? |
| Q1250 |
– |
Working with phosphorus-32 |
| Q1333 |
– |
Trilinear Chart of the Nuclides |
| Q2870 |
– |
Chart of the nuclides |
| Q2958 |
– |
GE chart of the nuclides |
| Q3269 |
– |
Activity versus dose |
| Q4059 |
– |
Biological and physical half-lives of technetium-99m |
| Q4423 |
– |
Specific activity |
| Q4754 |
– |
Heat generation |
| Q4905 |
– |
Calculate potassium-40 activity |
| Q6091 |
– |
Radionuclide emissions, energies, and half-life and effects on dose/damage |
| Q8270 |
– |
How does one obtain the half-life for long-lived radionuclides? |
| Q8820 |
– |
How can activity increase with radioactive decay? |
| |
Radiation Quantities and Units
|
| Q54 |
– |
What is |
| Q257 |
– |
How does one convert from R to rem? |
| Q412 |
– |
Information about SI Units |
| Q471 |
– |
What is a half life? |
| Q583 |
– |
Is the sievert named after someone? |
| Q924 |
– |
Radiation conversion units |
| Q930 |
– |
E notation |
| Q1001 |
– |
Convert dpm to microcuries |
| Q1252 |
– |
Define effective dose |
| Q2282 |
– |
Tritium unit |
| Q2779 |
– |
Convert sievert to rem |
| Q4066 |
– |
Determine specific activity |
| Q4219 |
– |
Convert gauss to millisieverts |
| Q4609 |
– |
Convert pCi/L to gram equivalents/L |
| Q4745 |
– |
The gray unit |
| Q7868 |
– |
Is effective dose a practical quantity in operational health physics? |
| Q10010 |
– |
Why is the term stopping power being used for photons? |
| |
Radiation Shielding
|
| Q44 |
– |
Can lead protect us from radiation because of its density? |
| Q62 |
– |
Where is the 2 mr/hr distance for a source wrapped with a 2-cm shielding material? |
| Q802 |
– |
What is the half value thickness for lead and stainless steel? |
| Q1094 |
– |
Materials for attenuating radiation |
| Q1318 |
– |
Lead for shielding beta particles |
| Q1531 |
– |
New shielding material |
| Q1723 |
– |
Irradiation of mail |
| Q2041 |
– |
Shielding for organic thorium fluorides |
| Q2781 |
– |
Shielding for iridium-192 |
| Q4418 |
– |
Photo attenuation |
| Q5505 |
– |
Dose Rate and Self-Absorption from Annular Source |
| Q5643 |
– |
What material properties affect shielding of x rays? |
| Q5735 |
– |
Density and attenuation data for sand as radiation shield |
| Q6393 |
– |
Can I calculate transmission through a laminated shield? |
| Q6960 |
– |
Use of water to shield Iridium-192 photons |
| Q8135 |
– |
How do I determine HVL for brass? |
| Q8929 |
– |
Depleted uranium as shielding |
| Q9724 |
– |
What boron-based buffer is available for neutron shielding? |
| |
Secular Equilibrium
|
| Q2770 |
– |
Calculate the specific activity of protactinium-234m |
| |
Miscellaneous
|
| Q280 |
– |
Where can I get information on carbon-14? |
| Q295 |
– |
How would you calculate the approximate activity of 1 oz. of Thorium Nitrate in Ci? |
| Q422 |
– |
Define particle |
| Q794 |
– |
Bremsstrahlung Spectrum in tissues |
| Q861 |
– |
Radiation transport |
| Q910 |
– |
Unpaired electrons and radioactivity |
| Q1055 |
– |
Convert mR to mrad |
| Q1083 |
– |
How to detect radiation |
| Q1179 |
– |
Half-value of lead |
| Q1276 |
– |
Density of material and half-value thickness |
| Q1286 |
– |
Lead for shielding |
| Q1308 |
– |
Neutron shielding calculation |
| Q1481 |
– |
HVL for cobalt-60 |
| Q1588 |
– |
Inverse square law |
| Q1744 |
– |
Radiation units |
| Q1778 |
– |
Equilibrium |
| Q1816 |
– |
History of radiation physics texts |
| Q2033 |
– |
Half-value thickness of lead and stainless steel |
| Q2036 |
– |
Effective half-lives |
| Q2419 |
– |
Intensity of x-ray field |
| Q2549 |
– |
Radium-226 decay |
| Q3047 |
– |
Can x rays make materials radioactive? |
| Q3471 |
– |
Handling processed film |
| Q3488 |
– |
Does alpha decay produce bremsstrahlung? |
| Q4113 |
– |
Activity and mass relationship |
| Q5133 |
– |
Radiation lifetimes |
| Q5456 |
– |
Uncertainty in the mean |
| Q5559 |
– |
How do you determine half-lives of short-lived radionuclides |
| Q5568 |
– |
Contamination of Baltic Sea compared to local water supply |
| Q5592 |
– |
Definitions of secondary contamination and secondary exposure |
| Q5731 |
– |
Protection afforded by vinyl gloves |
| Q5790 |
– |
Do radiation interactions product radioactive products? |
| Q5791 |
– |
Dose from thickness gauge radiations |
| Q5826 |
– |
Oxidation state and gram equivalent |
| Q5827 |
– |
Gram-equivalent and specific activity |
| Q5835 |
– |
Charcoal or HEPA filtration for sulphur-35 methionine? |
| Q5869 |
– |
Radioactive decay video/image resources |
| Q5878 |
– |
Why not simultaneous alpha and beta decay? |
| Q5890 |
– |
X rays from cathode-ray tubes |
| Q5939 |
– |
Convert activity to parts per million |
| Q5984 |
– |
Is charge conserved during alpha and beta decay? |
| Q6042 |
– |
What does it mean when the external hazard index exceeds unity? |
| Q6139 |
– |
X rays from high-voltage vacuum tubes |
| Q6421 |
– |
Quantities and units for electromagnetic fields |
| Q6511 |
– |
How often should I change the filter in my respirator? |
| Q6747 |
– |
Mass-activity conversions for radionuclides in solids, liquids, and gases |
| Q6756 |
– |
What are the risk and protection considerations when machining a thorium alloy? |
| Q6833 |
– |
What thallium isotope was used to poison Khokhlov? |
| Q6865 |
– |
Should a surface contamination wipe cover a specified area? |
| 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 |
| Q7923 |
– |
Can nonionizing radiation be converted to ionizing radiation? |
| Q8325 |
– |
Dose, dose rate, and biological risk |
| 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 |
