Target-moderator-reflector performance: An instrument designer's perspective

摘要

This paper focuses on two issues. The first of these is the necessity for close interaction between instrument designers and moderator designers. Several tools that would help facilitate this interaction are discussed. These include a database of moderator performance measurements and calculations and improved calculational capabilities that would permit rapid response to new moderator ideas or requirements. The second issue addressed is the importance of background in determining the quality of the data, with emphasis on the idea that in many measurements parts of the pulse shape itself act as background. Examples illustrate cases in which the instruments are better off if the source produces fewer neutrons, provided the missing neutrons are eliminated from the tail of the pulse rather than from the peak.