# Custom Material, spin **URL:** \ **Category:** Geometry and Materials\ **Created:** [14 October 2024 06:31 UTC](https://fluka-forum.web.cern.ch/t/custom-material-spin/6562 "2024-10-14T06:31:26Z")\ **Posts on this page:** 3\ **Page:** 1
**Author:** ![lklippha](https://fluka-forum.web.cern.ch/letter_avatar_proxy/v4/letter/l/3d9bf3/32.png) [@lklippha](https://fluka-forum.web.cern.ch/u/lklippha)\ **Post date:** [14 October 2024 06:31 UTC](https://fluka-forum.web.cern.ch/t/custom-material-spin/6562/1 "2024-10-14T06:31:26Z")
Hello FLUKA experts, I have a tungsten target in my set up. To simplify we currently use W184 only this one isotope for the target, as it has the largest abundace fraction of the naturally occuring (stable) tungsten isotopes. Though interesting is also tungsten W183, as it is fermionic, unlike the other stable tungsten isotopes (182, 184, 186). I was now wondering if FLUKA takes the spin of the isotope also into account when defining it via a MATERIAL card? I would be thankful for a reply! Kind regards, Laney Klipphahn ---
**Author:** ![ceruttif](https://fluka-forum.web.cern.ch/user_avatar/fluka-forum.web.cern.ch/ceruttif/32/23_2.png) [@ceruttif](https://fluka-forum.web.cern.ch/u/ceruttif)\ **Post date:** [14 October 2024 19:07 UTC](https://fluka-forum.web.cern.ch/t/custom-material-spin/6562/2 "2024-10-14T19:07:45Z")
The [MATERIAL card](https://flukafiles.web.cern.ch/manual/chapters/description_input/description_options/material.html) allows you to define a material made out of a single isotope type (e.g., 183W) - as you already know from the use of 184W - thanks to the WHAT(6) field. On top of it, there is no need to input its ground state spin, since FLUKA already knows it. ---
**Author:** ![horvathd](https://fluka-forum.web.cern.ch/user_avatar/fluka-forum.web.cern.ch/horvathd/32/10584_2.png) [@horvathd](https://fluka-forum.web.cern.ch/u/horvathd)\ **Post date:** [4 November 2024 13:21 UTC](https://fluka-forum.web.cern.ch/t/custom-material-spin/6562/3 "2024-11-04T13:21:07Z")