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Q: jeol 6400 fsem (field emission) ( No Answer,   2 Comments )
Subject: jeol 6400 fsem (field emission)
Category: Science > Instruments and Methods
Asked by: santexs-ga
List Price: $5.00
Posted: 03 Nov 2005 10:42 PST
Expires: 30 Nov 2005 16:54 PST
Question ID: 588464
We have an installed field emission sem which is exhibiting unstable
emission currents.  Vacuum levels in all parts are at acceptable
levels (gun chamber and int chamber are in the 10^-8 and 10^-7 Pa
respectively.  The specimen chamber is at 8x10^-7 Torr.) When the
accelerating voltage is turned on, the extraction voltage ramps up and
the emission current fluctuates wildly.  Pressing 'emission current
reset' results in a request to 'flash' the emitter.  Flashing the
emitter does not improve the stability.  I know the emitter element is
less than a year old (so it should still be good).  Any ideas?
There is no answer at this time.

Subject: Re: jeol 6400 fsem (field emission)
From: elids-ga on 03 Nov 2005 10:47 PST
A much better place for this type of question would be the engeneering tips forum;
Subject: Re: jeol 6400 fsem (field emission)
From: semicro-ga on 30 Nov 2005 15:46 PST
Sounds like there may be a contamination problem. Look carefully in
emitter area for "whiskers" or other contamination. Do not rule out a
failed emitter.

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