LIQUID-HYDROGEN COLD MODERATOR OPTIMIZATION AT THE BUDAPEST-RESEARCH-REACTOR

At the Budapest Research Reactor (BRR) the main functional element of the planned cold neuron source (CNS) is a special moderator cell fille d with liquid hydrogen and placed at the end of a horizontal beam chan nel in the Be reflector close to the maximum of thermal neutron distri bution. The moderator cell is inside an explosion proof vacuum case pr eventing the reactor itself from any damage even in the worst possible accident. Two versions of the moderator cell both directly cooled wit h cold He gas are compared.