Performance of a Silicon-Drift Detector in 200kV TEM Environments

Conference · Thu Jan 01 04:00:00 EST 2009

DOI:https://doi.org/10.1017/S1431927609099061· OSTI ID:1362179

Allard, Jr, Lawrence Frederick ^[1]; Rozeveld, Steve ^[2]

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1. ORNL
2. Dow Chemical Company, Midland, MI

Silicon-drift detectors for energy-dispersive spectroscopy have gained increasing acceptance in the field principally because of their outstanding capabilities for high count-rate performance coupled with excellent resolution [1,2]. Improvements in design in the last few years have overcome some early disadvantages of the SDD in comparison to Si(Li) detectors, which have dominated the field for nearly 4 decades. Amongst these are detection efficiency in the low-energy regime, and a dropoff in detection efficiency at higher energies above 10keV. The former disadvantage has been largely overcome by generational design improvements to minimize the effective dead layer at the entrance window, so that present detectors provide better performance in the low-energy regime than Si(Li) detectors. In the latter case, higher energy peak detection performance has been improved by increasing the thickness of the detector. This is important primarily for the use of the SDD in a TEM environment, where very high count rates are not encountered due to the thin sample geometry. Also of importance for incorporation of an SDD into a TEM column is the lack of need for liquid nitrogen, since the SDD is chilled by a thermoelectric cooler. This is an advantage for SEM and microprobe operation also, but high-resolution TEMs (particularly aberration-corrected instruments) are more sensitive to vibration than SEMs or microprobes, so the much reduced form factor of an air-cooled SDD relative to a Si(Li) detector with a large LN2 dewar is desirable for use on the TEM. We have recently tested two Bruker C

• Research Organization: Oak Ridge National Laboratory (ORNL), Oak Ridge, TN (United States). High Temperature Materials Laboratory (HTML)
• Sponsoring Organization: EE USDOE - Office of Energy Efficiency and Renewable Energy (EE)
• DOE Contract Number: AC05-00OR22725
• OSTI ID: 1362179
• Country of Publication: United States
• Language: English

Related Subjects

200kV TEM
SDD
aberration-corrected
energy-dispersive
performance