Last version:
FLUKA 2023.3.3, January 31st 2024
(last respin 2023.3.3)
flair-2.3-0d 13-Sep-2023

News:

-- Fluka Release
( 31.01.2024 )

FLUKA 2023.3.3 has been released.
Next FLUKA Course
The 23rd FLUKA course
will be held at the Lanzhou University, China, on June 1-8, 2024


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Material definitions

Q:

When and why do I need to input a MAT-PROP card?

A:

The density which is provided by the user via the WHAT(3) of a MATERIAL card is used for transport, i.e. it is used to convert cross sections to mean free paths. Therefore, it must be the actual density in case of a gas at non-atmospheric pressure, or the average density in case of a non uniform material. However, it is not sufficient because:
  • if the material is a gas, the Sternheimer-Peierls formula must be evaluated first at NTP and then corrected for actual TP. The density at NTP used in the evaluation of the formula is derived as MATERIAL-WHAT(3)/MAT-PROP-WHAT(1)
  • the material density can be non-uniform (for instance a material with voids (like a sponge or a powder). Transport (mean free path) is evaluated based on the average density MATERIAL-WHAT(3), while dE/dx must be evaluated based on local density MATERIAL-WHAT(3)/MAT-PROP-WHAT(2).

Q:

When using names for region how are ranges of regions defined with ASSIGNMA?

A:

The ranges refer to the order of appearance in the region definition section of your geometry and are not defined alphabetically.



Last updated: 26th of April, 2016

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