Charge amplifiers
Charge amplifiers
(OP)
Hi dear all,
Designing a charge amplifier, what primary parameter one should look for? I mean if one has to amplify presence of a few ions?
Thanks
Zahid
Designing a charge amplifier, what primary parameter one should look for? I mean if one has to amplify presence of a few ions?
Thanks
Zahid





RE: Charge amplifiers
A few ions, that's sub-attocoulomb. Can it be done?
Gunnar Englund
www.gke.org
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100 % recycled posting: Electrons, ideas, finger-tips have been used over and over again...
RE: Charge amplifiers
Dan - Owner
http://www.Hi-TecDesigns.com
RE: Charge amplifiers
RE: Charge amplifiers
This article has some interesting info on measuring sub-nano-amp currents. It has some good info on the pitfalls of measuring very small (femtoamp) currents, one of which is when using a capacitor to integrate currents for measuring. Physically large caps are more prone to interactions with cosmic rays, (read: ionization events). Since your application is to measure (or maybe count, since you're looking at basic chunks of charge) ions, you might turn this problem to your benefit.
A plug for www.rfcafe.com which fortuitously had this link.
RE: Charge amplifiers
Keith Cress
Flamin Systems, Inc.- http://www.flaminsystems.com
RE: Charge amplifiers
Having an amplifier capable of picoamps is like measuring millimeters with a blank yard-stick. And nanoamps is like measuring microns with same stick. Can't be done.
Gunnar Englund
www.gke.org
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100 % recycled posting: Electrons, ideas, finger-tips have been used over and over again...
RE: Charge amplifiers
RE: Charge amplifiers
Dan - Owner

http://www.Hi-TecDesigns.com
RE: Charge amplifiers
And turning on the light will increase leakage.
Gunnar Englund
www.gke.org
--------------------------------------
100 % recycled posting: Electrons, ideas, finger-tips have been used over and over again...
RE: Charge amplifiers
1: throw the ions into something like a microchannel plate
2: use either conventional CCD or charge multiplication CCD for readout
3: TE cool the lot.
TTFN
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RE: Charge amplifiers
TTFN
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RE: Charge amplifiers
Gunnar Englund
www.gke.org
--------------------------------------
100 % recycled posting: Electrons, ideas, finger-tips have been used over and over again...