I need to identify the peaks in this boron mass spectrum

As part of a bigger project we were given this image. Its a mass spectrum produced in an accelerator with a Boron cathode. It was implanted in diamond. I assume the first peak is just $$B^-$$ but I have no clue what the rest is. Any help would be appreciated

• Given that boron has two isotopes (10 and 11), and your low mass peak looks more like it is at mass 9, you indeed have some issues. Further, why a negative ion (unless you have a tandem accelerator and are just looking at the SNICS source)? – Jon Custer Jun 24 '19 at 16:48
• It is indeed a SNICS source – Pablo Bähler Jun 24 '19 at 17:30
• You said the spectrum taken with a boron cathode. It is seemingly, $\ce{^{10}B}$ enriched cathode and I clearly see the presence of $\ce{^{10}B3}$ (very weak), $\ce{^{10}B4}$ (weak), and $\ce{^{10}B5}$ (strongest) peaks. To assign peaks at 38 and 49, I need to know how was the cathode prepared (such as with $\ce{Ag}$ or $\ce{C}$ or etc.). – Mathew Mahindaratne Jun 24 '19 at 17:34
• The supervisors for the experiment did not tell us anything about the preparation, it is a side task for the main experiment, which is implantation of ions in diamond to create nitrogen vacancy centers. – Pablo Bähler Jun 24 '19 at 18:57
• @MathewMahindaratne - But I see no indication of a $B_{2}^{-}$ peak, which shows up clearly in the scans in the Negative Ion Cookbook. But, yes, the OP should clarify what cathode was used. – Jon Custer Jun 24 '19 at 19:00