Abstract. A new spectrometer called SMARTS (Spectrometer for Materials Research at Temperature and Stress) has been commissioned at the Los Alamos neutron science center and entered the user program in August of 2002. Its design maximizes capability and throughput for measurements of (a) residual macrostrain in engineering components and (b) in situ loading. This paper describes some aspects of the instrument. 61.12Ex; 62.20Fe; 62.20Hg Measurements of strain in engineering materials place demands on neutron diffraction spectrometers that differ from instruments designed for conventional crystallography. Notably the range in shape and size of engineering specimens requires more spacious access to the sample position than is typically found on conventional diffractometers. Moreover efficient and accurate measurements require precise optical alignment (of samples with irregular shapes) with respect to the beam -which imposes limitations on shielding and lineof-sight access to the sample. Over the last few years these limitations have led to adaptation of existing instruments and new instruments being designed for engineering strain measurements PACS
