Introducing the term “probe high tension” and extreme x-ray collection efficiency on Spectra Ultra S/TEM
- Abstract number
- 14
- Presentation Form
- Poster Flash Talk + Poster
- Corresponding Email
- [email protected]
- Session
- Stream 2: EMAG - In-situ microscopy
- Authors
- Dr. Anil Yalcin (1)
- Affiliations
-
1. Thermo Fisher Scientific
- Keywords
Solid angle, beam sensitive specimens, low dose imaging, high tension flexibility
- Abstract text
Besides being the first commercial platform with corrector(s), first generation Titan was capable of high tension range from 300 kV down to 80 kV. For improved optical and specimen stability, bifilar coil design was introduced in the objective lens unit [1], enabling swift mode switches at a certain high tension operation. Overnight high tension switches have become the norm, and since then, market expectations have moved forward that current S/TEMs have a high tension range down to 30 kV with stability achieved over a couple of hours. This timescale can be seen long in some cases, for instance, S/TEMs shared by several multi-disciplinary research groups.
Research community has also driven the market in terms of x-ray collection efficiency and output count rate maximization in elemental studies. Lithium doped silicon (Si(Li)) EDS detectors were replaced with silicon drift detectors (SDDs) and Super-X became the first EDS detection system with multiple SDDs on a S/TEM [2]. Growing beam sensitive materials research field and time to data considerations have brought solid angles to around 2 sr and output count rates to 1 million cps.
Recent advances in R&D allow us to introduce a new platform within the Spectra portfolio, which will address the above mentioned market demands in full. This new member, Spectra Ultra S/TEM, is equipped with an EDS detection system allowing unshadowed solid angle of above 4 sr without any compromise in terms of spatial resolution (i.e. larger pole piece). Moreover, Spectra Ultra S/TEM can stabilize within minutes after a high tension switch, whereby introducing the term “probe high tension” to the TEM community. In this way, one can now use high tension as an experiment variable similar to changing probe current or convergence angle in microscope operation.
We believe that Spectra Ultra S/TEM will further accelerate research in beam sensitive materials. Thanks to the unprecedented x-ray collection efficiency, extreme low doses can now be used to generate high quality elemental maps. Furthermore, depending on the specimen behavior under the electron beam, probe high tension can be tuned as often as needed for experiment optimization.
- References
[1] van der Stam, M. et al. Microsc. Microanal., 2005, 19, 9-11.
[2] Schlossmacher, P. et al. Microsc. Microanal., 2010, 24, S5-S8.