# 1D projection for specified area

Dear FLUKA experts,

The 1D projection for the Dose part provides the absorbed dose [GeV/g/primary] versus depth [cm], Which is averaged over the x and y axes for each cell of z. Is it possible to obtain this average for a specific area on the x and y axes? I need to determine the absorbed dose in eV/atom. When using the 1D projection plot, the average over the x-y plane is much lower than the estimation. This is because there are some atoms that do not absorb any energy. Therefore, it is better to average only over the area that absorbed energy, rather than the entire area. Can you advise on how to estimate the volume that absorbed energy?

Best regards,
Marziyeh

Dear Marziyeh,

Thanks for your message. If I understand your problem correctly, you are using a 3D `USRBIN` mesh with `DOSE` as estimator and, for the moment, you are plotting the 1D projection over Z of your estimator, averaged over all X and Y bins. I assume you are using an `X-Y-Z` `USRBIN` with a number of bins N_x, N_y and N_z for X, Y and Z, respectively. If you are interested in restricting the X,Y range on which the 1D average is calculated, you can do this directly in the `Plot` tab available in Flair (see an example in the picture below), by selecting the range on X and Y and center this area around your region of interest.

Cheers,
Marco

Dear Marco,

Thank you very much for your response.
Yes, that is correct.
And I want to know the average absorbed dose, which is the total absorbed energy (or dose[eV/atom]) divided by the volume (or atoms) that received the energy, not the entire volume of the material. If the volume is very large, then the average will be very low. For example, if you have a laser source that could damage your sample, it doesn’t matter how big your sample is.
B4C_Grazing.inp (4.0 KB)
B4C_Grazing.flair (4.4 KB)

Best,
Marziyeh