This Science in Developing Countries award supports an international workshop on instrumentation in elementary particle physics to be held at the Brazilian Center for Physics Research (CBPF) in Rio de Janeiro, Brazil from July 16-28, 1990. The U.S. organizer is Marleigh Sheaff of the University of Wisconsin in Madison while her counterpart is Joao Carlos Costa Anjos of CBPF. A large number of U.S.-Latin American collaborative experiments are carried out at Fermilab where Dr. Sheaff does her experimental work. Fermilab will contribute to the support of this workshop. The participants will come from all over Latin America and the Carribean: Argentina, Bolivia, Brazil, Chile, Colombia, Costa Rica, Dominican Republic, Ecuador, Honduras, Mexico, Peru and Puerto Rico. There will be physicists from several European countries including Poland and from Japan, the Peoples Republic of China, Egypt, India and the U.S.S.R. as well as from Canada and the U.S. Two of the five laboratory demonstrations planned for the Rio School will be prepared and taught by Latin Americans from Brazil and Mexico. Thus there is a significant benefit to be derived from this workshop by participants from around the world. It will include hands-on laboratory experience in instrumentation techniques and lectures on state-of-the art detector research given by scientists actively involved in the field.