Hello!
When you request LET as quantity to score in USRYIELD, the unrestricted
LET is scored, so thresholds should be largely irrelevant.
By the way, note that default threshold values are indicated in the
manual (see section on the GLOBAL card) and are also accessible in the
output file. See slides 32-34 in
Note that for electron/positron projectiles, the transport threshold
(search Ecut in slides / output file) and delta-ray production
thresholds (search for Ae) are given as total energy, i.e. rest mass +
kinetic energy, exceptionally in MeV.
With kind regards,
Cesc
PS: Being picky, the lower one sets the thresholds, the larger is the
fraction of losses that is sampled explicitly, leading to a
progressively more refined account of the simulated radiation field.
This can be of relevance in particularly detailed or fine-grained
geometries. If you lower your thresholds (e.g. change from HADROTHE to
PRECISIO defaults) and do not see noticeable changes, the
aforementioned detail is likely irrelevant.