In this space, visitors are invited to post any comments, questions, or skeptical observations about Philo T. Farnsworth's contributions to the field of Nuclear Fusion research.
Subject: Re: clarification (Mass spec)
Date: Aug 13, 4:44 pm
Poster: Jim Lux
On Aug 13, 4:44 pm, Jim Lux wrote:
>That said, the detector is perhaps the most important part. This is true also for the refurbished units. Sometimes, you might get a real treasure.. when the electron multiplier gets >==================
>Most modern Mass Specs can sit on a number of AMU's to monitor selected species directly. But the measurements are not really simutaneous. The minimum dwell time for a measurement in a quadrupole MS, is the time of flight at a few EV energy down the 20 cm or so to the detector -- probably no more than a few milliseconds. Then, on to the next species.
>I think, as Jim has hinted at, the magnetic sector MS, is capable of simultaneous measurments... provided you could get the several detectors into the beam paths.
Without a lot of thought as to feasibility, I am wondering whether a CCD array or a dynamic ram, with the lid off, might not make a reasonable detector. Kind of depends on what the structure of the IC is, and whether there is a passivating layer, and how good the focussing of your filter is. I know there is some guy at JPL who is making very sensitive charge detectors in this way (using them to do things like weigh individual viruses, with each virus charged with 1 e- ), but his chips are custom made, and somwhat expensive, I should think.
- Re: clarification (Mass spec) - Dave Cooper Aug 14, 0:40 am