someonan, Consists of a ion-chamber-type survey meter. A device for measuring the amount of ionizing radiation. gas-filled chamber Containing two electrodes (one of which may be the chamber wall) between which a potential difference is maintained. The radiation jonizes gas in the chamber and an instrument connected to one electrode measures the ionrzation current produced. vontzation. The process of adding electrons to, or knocking electrons from, atoms or molecules, thereby creating 1ons. High temperatures, electrical discharges, and nuclear radiation can cause ionization. jonizing radiation. Any particulate or electromagnetic radiatyon capable of producing ions, directly or indirectly, in its passage through matter. Alpha and beta particles produce jon pairs directly, while gamma rays and X-rays liberate electrons as they traverse matter, which in turn produce jonization in their paths. ‘enosgrere. arth, The region of the atmosphere, extending from roughly 40 to 250 miles (64 to 400 km) above tne in which there is aoprec:aiz icr-zation. The presence of charged particles profound!yv affects tre pervayatian of radio and radar waves. irradiation. in this region Exposure of matter to radiation. isodose lines. Dose or dose-rate contours. In fallout, contours platted on a radiation field within which the dose rate or the total accumulated dose is the same. isotope. Atoms with the same atomic number (same chemical element) but different atomic weight; i.e., the nuclet have the same number of protons but a different number of neutrons. JCS. Joint Chiefs of Staff. JTF 7. Joint Task Force 7 and its predecessor, JTF 132, was a combined force af personnel af the Department of Defense (Air Force, Army, Marine Corps, Navy), the AEC, and their contractors. JTF 7 was responsible for all aspects of nuclear weapon tests in the Pacific testing area from 1953 to 1958. The last atmospheric nuclear test in the Pacific was conducted by JTF 8. 8-29. Aerial refueling version of the B-29, L-13. Single-engine, 2-place light aircraft used in Enewetak airlift. _ kinetic energy. ASL. Los Alamos Scientific Laboratory, Los Alamos, New Mexico. cP(L). LCP(R}. Landing craft, personnel (large). Landing craft, personne? (ramp). Landing craft, LCU. Utility landing craft. c LcT M tank. Lookout Mountain Laboratory, Hollywood, California (Air Force). Loran. Long-rafige navigation system. Enewetak Island. LSO. One Loran station was maintained by the U.S. Coast Guard Station on Landing ship, dock. LSIL. LST. . Landing craft, mechanized. me] r- LOM. Energy associated with the motion of matter. Landing ship, infantry (large). Landing ship, tank. MATS. Military Air Transport Service; later, Military Airlift Command (joint Air Force). megaton (energy). Approximately the amount of energy that would be released by the explasion of one million tons of TNT. microcurie. micron. Qne-millionth of a curte. One-millionth of a meter (i.e., 10-6 meter or 10-4 centimeter); it is roughly four one-hundred- thousandths (4 x 10-5) of an inch. 478