Pu Ma in U is quite hopeless, we do not do that. U Mb is in the way, the correction is enormous. We do Pu Mb in U, and still we have to correct for U M3-N4 and a bit of U Mg.
We only use Pu Ma when there is also Am and Cm, because then Pu Mb is totally hopeless....
![Smiley :)](https://probesoftware.com/smf/Smileys/default/smiley.gif)
Cm Ma in right on top.
We use a Qtz 10-11 crystal though with a bit better resolution. PET gives more counts but the lines are a bit closer together. And we have a Rowland circle of 180 mm which also helps. But in the good old days, on the MS46, we had 220 mm, that was really good...