Radiation Basics

The following FAQs have been developed by our topic editors for this category:

			How Can You Work Safely Around Radiation?
			Radiation Basics
			Radioactivity Units
			Relationship Between Radionuclide Gamma Emission and Exposure Rate
			What Is Radiation?
			What Is Radioactive Contamination?
			What Types of Radiation Are There?

The following HPS Web page also addresses this category:

Shielding of Gamma Radiation

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
•  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?
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.
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?
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
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?
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?
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?
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?

The following Web sites may also be useful:

			Basics About Radiation (RERF)
			Definitions and Units (ORAU)
			General Atomics
			Ionizing Radiation (OSHA)
			Nuclear Data
			Radiation and Radioactivity (U. Michigan)
			Radiation Basics (CDC)
			Radiation Information (Idaho State University)
			Radiation Risk (NRPB)
			Radiation Shielding Textbook
			Radiation Terminology (Univ. of Michigan)
			Radioactive Isotopes (LBL)
			Radionuclides (EPA)
			Understanding Radiation (EPA)