image intensifier

noun

image in·​ten·​si·​fi·​er -in-ˈten(t)-sə-ˌfī(-ə)r 

: a device used especially for diagnosis in radiology that provides a more intense image for a given amount of radiation than can be obtained by the usual fluorometric methods

image intensification

-in-ˌten(t)s-(ə-)fə-ˈkā-shən 

noun