LV-Series - For low-voltage TEM applications
From Direct Electron
The LV-series TEM cameras were specially designed for low-voltage TEM application such as LEEM/PEEM. These cameras are equipped with the direct detection technology and achieve extraordinary results compared to traditional detectors like channel plates +CCD.
Transmission electron microscopy (TEM) is a very powerful and commonly used tool to visualize samples with a resolution in the nanometer or Angstrom range. One limiting factor regarding the final resolution is the general physics in electron scattering which is very strong in the low-dose imaging regime. Beside this the general architecture of the TEM, charging effects, dynamic processes like drift or beam-induced motion of the sample will also have influence on the achievable resolution of your image. Some of these factors can be controlled by the operator but the final resolution will depend on the used detector. The detector will have to meet highest standards with respect to resolution, speed, sensitivity and signal-to-noise ratio. Traditional scintillator-CCD cameras show a clear limitation which was the reason Direct Electron developed as the first manufacturer a new kind of TEM camera architecture. This revolutionary Direct Detection Device (DDD®) sensor was recognized with the 2010 Microscopy Today Innovation Award.
Principle of Direct Detection Device (DDD®) sensors
This new type of sensor directly detects incoming electrons without the need of a scintillator as it would be used in a traditional TEM camera. The incoming electron will pass through a very thin layer leaving an ionization trail. They can now either be counted or integrated. Due to the very low thickness of this layer the normal lateral charge spread is minimized leading to a much higher resolution compared to other camera architectures. Secondly the architecture of the Direct Detection Device (DDD®) sensor allows a very high frame rate with no dead times between frames which makes this camera extremely useful for any kind of time critical in-situ TEM experiments.
Integrating and counting mode of the Direct Detection Device (DDD®) sensor
|The high frame rate and the very high single-electron sensitivity enable the DDD® sensor with two different sensing modes:|
Performance of the cameras
The LV-126 camera is specially designed for low-voltage applications and delivers a significant better resolution compared to traditional detectors. This higher resolution can be used to lower the magnification which will give you a larger field of view. You will get up to 8x times more information out of your image if you compare the results of the LV-125 camera image with a traditional detector image (assuming that you used the same resolution).