energy deposition on the target graphene&stainles steel

Dear fluka experts,

I want to calculate the energy deposition on the target which consists of steel (thickness of 0.1cm) and graphene (thickness of
1.42E-8cm).
the target geometry has steel+graphene+steel+graphene+....

I attached my input and figures of energy deposition on the target (only ss, only graphene and full target)

Q1;
Altough the graphene is stronger than steel (200 times) why the energy deposition on the graphene is lower than SS.
is there a mistake in my input?

Q2;
What is the RHOR factor (WHAT2 on MATPROP Card)for graphene

Q3;
What is the dE/dx (WHAT5 on MATERIAL card) for graphene

could you help me please

Best regards

Ertan Arikan