As a result of Dr. Koubek’s email to campus regarding the Governor’s executive order, I am cancelling all use reservations in the calendar this afternoon. We will be ready to begin again after we return from the stay at home 3 weeks from now.
ESEM in Electron Optics
We have made changes to the process of saturating the ESEM filament. Now we use Scan>Horizontal Line and monitor that line as the Filament slider is changed. Saturation occurs when the horizontal line stops increasing when the slide is increased. The point when it stops increasing is saturation, so you may overshoot and have to slide it back slightly. When you complete saturation return to Scan>Full Screen to stop the line. Click Filament Limit as you usually would. Any of you who learned to saturate the filament on the 6400 SEM will recognize this technique.
I want to show you how to do this so let me know when you’d want to see it done. It is really easy and there is no ambiguity when setting saturation like using the “football”. We will be making changes to the standard operating procedure.
This a a precise technique and the filament will last longer.
The ESEM is back online and ready to use.
I’m not certain what went wrong but I’m suspicious of the AZtec scan grabber. The AZtec software acquires an ESEM image by taking control of the ESEM scan hardware. When the scan is complete it should release the ESEM hardware. I have seen a few times that it doesn’t release. If you have trouble seeing a scanning ESEM image after acquiring with AZtec try to shut down the AZtec software and see if the scan returns. If it still down’t return contact me and I’ll take a look at it.
The ESEM is down with a computer problem. Don’t try to use it. I’ll
get it back online Monday morning and send out an update.
EDS detectors works like a thermos bottle that slow liquid nitrogen evaporation. When the vacuum in the detector deteriorates the liquid nitrogen that cools the detector evaporates quicker. That is happening in the ESEM detector. We refill the detector twice each week but depending on the timing you might hear an alarm signaling that the liquid nitrogen is low. The alarm is a beep signal every few seconds. Here is the important part of this message – if you hear the alarm let me, Aleister or Liz know so we can refill it.
I will have the vacuum replenished in the summer when ESEM use drops.
Thanks, Owen
The ESEM is back online and ready to use.
ESEM is down for the weekend with a vacuum problem. I’ll fix it Monday
1:56 p.m. ESEM filament is back online and working fine. Ready to use.
12:15 p.m. The filament burned yesterday after. We put a new one in this morning but its not working just right. We are working on it now.
It’s too hot to touch today, so we’ll get it back online tomorrow morning.
There was a report of no EDS spectra on the Aztek system. On examination we found 2 user-correctable issues. First, the backscatter detector was blocking part of the x-ray signal from reaching the detector. It was not in the correct orientation. Then, and this is the biggest issue, the Process Time was set to 2 and it should be on 5. Process Time 2 provides narrower peaks (energy resolution) but reduces the deadtime (count rate). The SOP lists 5 as the default position. If you change it, please return to 5 when your work is complete.
The EDS works fine and is ready to use.