The “Specific Gamma Ray Dose Constant”, sometimes known as the “Gamma Factor”, is the dose rate at a specific distance from a given amount of a photon-emitting radionuclide. These constants are used frequently for radiation protection purposes. The following is a listing of Specific Gamma Ray Dose Constants for a variety of radionuclides, in units of Rem per hour (Rem/hr) at a distance of one (1) meter from a one (1) curie point source of that radionuclide.**
Actinium
Aluminum
Americium
Antimony
Argon
Arsenic
Astatine
Barium
Berkelium
Beryllium
Bismuth
Bromine
Cadmium
Calcium
Californium
Carbon
Cerium
Cesium
Chlorine
Chromium
Cobalt
Copper
Curium
Dysprosium
Einsteinium
Erbium
Europium
Fermium
Fluorine
Francium
Gadolinium
Gallium
Germanium
Gold
Hafnium
Holmium
Indium
Iodine
Iridium
Iron
Krypton
Lanthanum
Lead
Lutetium
Magnesium
Manganese
Mercury
Molybdenum
Neodynium
Neptunium
Nickel
Niobium
Nitrogen
Osmium
Oxygen
Platinum
Plutonium
Polonium
Potassium
Praseodynium
Promethium
Protactinium
Radium
Radon
Rhenium
Rhodium
Rubidium
Ruthenium
Samarium
Scandium
Selenium
Silicon
Silver
Sodium
Strontium
Tantalum
Technetium
Tellurium
Terbium
Thallium
Thorium
Thullium
Tin
Titanium
Tungsten
Uranium
Vanadium
Xenon
Ytterbium
Yttrium
Zinc
Zirconium
**Listing partially extracted from ORNL/RSIC-45, “Specific Gamma-Ray Dose Constants for Nuclides Important to Dosimetry and Radiological Assessment”, May, 1982. Please note that these constants are for individual radionuclides only and not for decay series (e.g., U-238 plus progeny; Th-232 plus progeny, Ra-226 plus progeny, etc.)