D
Daniel Haude
Hi folks,
some colleagues approached me about this, thinking I might be able to
build something for them. I don't think it'll work though.
What they want to do is to oscillate a quartz cantilever at about 100kHz
with an amplitude in the order of a few angstroms. This translates to an
electrical ampltitude across the electrodes of less than a mV and a total
oscillation energy of about 20 eV!
The oscillator would be mounted in a vacuum so air damping wouldn't be an
issue.
Of course it's no problem to just drive the quartz with a small AC voltage
to get it to oscillate with the desired amplitude, but is it possible to
operate the quartz as a resonating oscillator at such low levels? At the
end of about two meters of cable?
I don't think it can be done, but I'm always very pessimistic. 20eV,
sheesh! A single UV light quant! I'd welcome any ideas on this. The
objective, by the way, is to measure changes in the resonant frequency of
the cantilever caused by a force gradient.
Thanks,
--Daniel
some colleagues approached me about this, thinking I might be able to
build something for them. I don't think it'll work though.
What they want to do is to oscillate a quartz cantilever at about 100kHz
with an amplitude in the order of a few angstroms. This translates to an
electrical ampltitude across the electrodes of less than a mV and a total
oscillation energy of about 20 eV!
The oscillator would be mounted in a vacuum so air damping wouldn't be an
issue.
Of course it's no problem to just drive the quartz with a small AC voltage
to get it to oscillate with the desired amplitude, but is it possible to
operate the quartz as a resonating oscillator at such low levels? At the
end of about two meters of cable?
I don't think it can be done, but I'm always very pessimistic. 20eV,
sheesh! A single UV light quant! I'd welcome any ideas on this. The
objective, by the way, is to measure changes in the resonant frequency of
the cantilever caused by a force gradient.
Thanks,
--Daniel