31. Since 1990 North American had produced precisely measured radiation sources for calibrating medical and industrial nuclear equipment. 32. The radiation source serves to increase the reliability of ignition and formation of the keep-alive electrode discharge. 33. After retrieval from the core, processing can extract the cobalt-60 for manufacture into a useful radiation source . 34. Radiant barriers are materials that reflect radiation, and therefore reduce the flow of heat from radiation sources . 35. Therefore, the radiation sources remain accurately targeted. 36. The gamma gardens were arranged in a circular pattern with a retractable radiation source in the middle. 37. Americium is commonly used in industry as both an alpha particle and low photon energy gamma radiation source . 38. In breast brachytherapy, the radiation source is placed inside the breast, treating the cavity from the inside out. 39. After eliminating every conceivable source of interference, they concluded that the radiation source was not of earthly origin. 40. In contrast, brachytherapy involves the precise placement of radiation source ( s ) directly at the treatment site.
