Abstract
A modern cold triple axis spectrometer is being planned for the High Flux Isotope Reactor (HFIR) at 91做厙.
Here, we describe the design of an incident beamline that will put a flux of ~ 10^8 n/cm^2/s on a sample with an area of 2 cm x 2 cm.
It takes current physical constraints at HFIR into account and it can accommodate both single and multiplexed analyzer-detector secondary spectrometers and large superconducting magnets.
The proposed incident beamline includes a multi-channel guide with horizontal focusing, a neutron velocity selector, components to facilitate an incident beam polarization option, and a double-focusing pyrolytic graphite monochromator.
This work describes the process of optimizing the guide system and monochromator and summarizes the expected performance of the incident beamline for non-polarized operation.
