The `ISIS_LET` Instrument

Site: ISIS
Author: Ross Stewart
Origin: ISIS
Date: September 2025

LET instrument on ISIS TS2 Instrument: ISIS_LET

Identification

This is a simulation of LET on ISIS TS2.

Parameters in boldface are required; the others are optional.

Name	Unit	Description	Default
Ei	meV	Centre energy for moderator	3.7
dE		Multiplier for energy spread: Emin = Ei/dE, Emax = Ei*dE	1.1
Ch3_speed	Hz	Chopper 3 frequency	100
Ch5_speed	Hz	Chopper 5 frequency	200
Ch2_phase	mus	Chopper 2 phase setting	95000
pha_offset	mus	Offset in time for moderator focus	80e-6
res	string	"HF" - High Flux, "HR" - High Resolution, "I" - Intermediate	"HF"
snout	string	"in" or "out"	"out"
monitors_on	1	Flag to enable/disable TOF monitors in primary optics	0
movable_monitors	1	Flag to enable/disable PSDs and Div monitors in primary optics	0