Abstract
Dead time effects in time-of-flight secondary ion mass spectrometry are well known and can be corrected for using Poisson statistics. Laser-induced desorption, however, introduces nonlinearity in the evaporation process resulting in highly fluctuating signals that make proper dead time correction much more challenging. Here, we propose a modified dead time correction procedure that overcomes such obstacles using data from correlated detection events from different isotopes of a single element. Provided the signals are not affected by unresolved mass interferences, this dead time correction enables us to obtain meaningful isotope ratios as demonstrated for atom probe tomography data of carbon from nanodiamonds and of silicon.
| Original language | English (US) |
|---|---|
| Pages (from-to) | 46-51 |
| Number of pages | 6 |
| Journal | International Journal of Mass Spectrometry |
| Volume | 379 |
| DOIs | |
| State | Published - Mar 15 2015 |
Funding
We thank M.J. Pellin and C. Floss for helpful discussions. We appreciate thoughtful comments by two anonymous reviewers. This work was supported by NASA through grants NNX09AG39G (T.S.), NNX11AG77G (P.R.H.), NNX13AF53G (J.B.L.), and NNX14AP15H (J.B.L.), and by a grant from the Tawani Foundation (P.R.H.). The LEAP tomograph at NUCAPT was purchased and upgraded with funding from NSF-MRI and ONR-DURIP programs. Instrumentation at NUCAPT was supported by the Initiative for Sustainability and Energy at Northwestern. This research made use of the EPIC facility and Shared Facilities at Northwestern University's Materials Research Science and Engineering Center, supported by the MRSEC program (DMR-0520513 and 1121262) of NSF. P.R.H. thanks Cameca Instruments, Inc., for access to their LEAP tomograph.
Keywords
- Atom probe tomography (APT)
- Dead time correction
- Laser-induced desorption
- Time-of-flight mass spectrometry (TOF-MS)
ASJC Scopus subject areas
- Instrumentation
- Condensed Matter Physics
- Spectroscopy
- Physical and Theoretical Chemistry