# How to specify an ion source such as 90Sr for a simulation?

i want to use an ion such as 90Sr for a project to do a simulaiton,
how shauld i do?

Dear @Newconcept_1979,

you can define an radioactive isotope as a source using the ISOTOPE particle type on the BEAM card, in conjunction with the HI-PROPE card. Furthermore, you need to activate the radioactive decay with the RADDECAY card (semi analogue mode), and associate the scorings with a DCYSCORE card.

For an example see slide 24 of the following lecture:

@ amario,thanks!