Natural Science Forum / Physics / Optics / November 2004

Probably the JEOL.  Both systems are W and simple SE detection.
However, the Quanta 200 does ESEM.  If the FEI is older, it likely has
the difficult user GUI.  A new JEOL would be better.  That said, if
you want more versatility, the Quanta is likely better.  Check on main
pumps for both.  The roughing pumps are usually Edwards RV8 but may be
Edwards XDS10 scroll pump for ESEM.  The main pump is either turbo
or diffusion.  The turbo is better but will have less reliability than
the diff.  If the turbo is dual mag lev, it will last a long time.
With a diff pump, back streaming is always an issue.   Check out
chiller requirements.  FEI has low flow rate.  Not sure about JEOL.

Check out the GUI for each and check the x, y, z and T movement
ranges.  Check vent and pump times.  Check max Z height.  

Either way, a W gun is not easy to work with.  It is a real pain.  If
you can get it with a LaB6 or CeB6 cathode, that is much better.
Beyond these, you are into FE territory where price goes way up.
If resolution is not critical and max mag is not high, W or xxB6 is
fine.  FEI generally does not have good support for its tools.  This
is mostly in their resistance to change the computer and GUI.  Some
are still running NT4 and could be running 2K or XP but field service
won't do the switch.

You can probably get a better price deal on a used Quanta.

Gary Gaugler, Ph.D.
Microtechnics, Inc.
Granite Bay, CA 95746
916.791.8191
gary@microtechnics dot com

If neither has a gun chamber ion pump, you cannot use other than W
filament.  This is a big problem and compromise.  W lasts about 100
hours at best and is not stable over that time.  LaB6 or CeB6 is at
least ten times brighter and lasts about ten times longer (1000 hours
versus 100 hours W).  No ion pump, no option.

Gary Gaugler, Ph.D.
Microtechnics, Inc.
Granite Bay, CA 95746
916.791.8191
gary@microtechnics dot com