Dear Experts,
I want to score LET spectrum using USERYIELD CARD. Defaults: HADROTHERAPY.
As per my understanding, It gives restricted LET. Am I correct ?
If it is resticted LET, ideally, how much Deltaray production threshold or particle threshold or EMF Cut value should I use to get LET for proton beam. Or default values for these parameter (Defaults: HADROTHERAPY) is good for it?
What is the default value of Deltaray production threshold in the case of Defaults: HADROTHERAPY card ?
Any help or suggestion please.
Thanking you in advance.
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.
Thank you for your reply.
I have one more doubt.
As per my understanding, LET scored by USERYIELD is boundary crossing i.e defined at the surface of the geaometry region. Am I correct?
So if I want to calculate depth wise LET_d (dose average), what shoul be the scoring region dimension (typically).
Whether any example input file is available for this kind of scoring ?
Waiting for reply.
Thanking you in advance.
As per my understanding, LET scored by USERYIELD is boundary crossing i.e defined at the surface of the geaometry region. Am I correct?
Yes. At a boundary crossing the particle energy is well defined and
so is the LET.
So if I want to calculate depth wise LET_d (dose average), what shoul be the scoring region dimension (typically).
If you go to the list of generalized particles in the FLUKA manual you
will see:
DOSEQLET 243 Dose equivalent with Q(LET) (GeV/g) (7)
(7) "Dose equivalent" is computed using the Q(LET) relation as
defined in ICRP60 [ICRP60], where LET is LET_oo in water.
ICRP60 International Commission on Radiological Protection, ICRP
Publication 60, Annals of the ICRP 21, 1-3 (1991)
Is this what you want? If so, then you should in principle be able to use a USRBIN and adapt the spatial resolution as you wish.