4 About Dose Protector

In order to prevent Falcon chip from over-dose irradiation, Tecnai 4.3.0 introduces a new software component called "Dose Protector". Every time when you start up TIA interface, you will have to calibrate a beam intensity before you can use Falcon camera. Otherwise, the beam gets planked as long as Falcon camera is in inserted position. For an user, only beam intensity is to be calibrated. Other system calibrations such as relative intensities for different spot size etc. should be done by Supervisor already. The calibration is done for each pair of Gun Lens and Extracting Voltage.

Calibrating the beam intensity is rather simple, you follow a three-step instruction and then you are done. As hinted above, if you don't plan to use the Falcon camera for your session, you can skip it.

Note: There are some system-wise calibrations beside the one done by an user after starting TIA. Those calibrations are done by Supervisor and are needed to be done for combinations of each Gun Lens and Extracting Voltage that one wants to use.

The protection from Dose Protector is very robust. It acts at TEMserver level. For example, before you calibrate the dose intensity or your beam intensity is out of the calibration range, you can not get an image from Falcon camera. If you do insert Falcon camera and try to take an image using SerialEM, you will get a “timeout” error message rather than getting a blanked image. This is very good, as we won't have worry about possible damage from using the third party software - SerialEM!