Corby that explains what I have been seeing and wondering about over the years I have had Cesiums. Get it all pumped down and then the next time I get those bursts. I am letting a recent 5061 pump down. It seems to get really dirty each time I start it but gets down to 16 on the meter after some 48 hours. I run the Cesiums at least per quarter. Really appreciate this insight you shared. Thank you. Paul WB8TSL
On Wed, Dec 2, 2020 at 2:27 PM <cdel...@juno.com> wrote: > The gettering in the tube is only for capturing any stray Cesium atoms > that don't get caught in the main gettering patch. If the gettering fails > or gets too loaded up then the Cesium background level will get too high > causing poor SN. > > The ion pump is for any gases. > > When a tube is off for extended times any gas atoms lingering or leaking > slowly into the tube than happen to impinge on either the mass > Spectrometer filament or the Cs oven filaments get capture by the > filaments. They function as excellent getters! (this even if the ion > pump is on) > > Now this is not by design but results in the filaments being "loaded" > with the gas atoms. > > Then when you turn the tube on the filaments light up and expell a burst > of gas. > > This of coarse causes the ion pump current to rise and trips off the > filaments, > > Once the ion pump removes the burst the cycle repeats until the filaments > have expelled the trapped gases. > > Then the ion pump can handle the load and pump the tube down completely. > > Cheers, > > Corby > > > _______________________________________________ > time-nuts mailing list -- time-nuts@lists.febo.com > To unsubscribe, go to > http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com > and follow the instructions there. > _______________________________________________ time-nuts mailing list -- time-nuts@lists.febo.com To unsubscribe, go to http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com and follow the instructions there.
