> This may be a dumb question but I'm going to ask anyway. With so many factors > affecting the hydrogen's masing (is that the correct term) frequency - > temperature, > pressure, magnetic field, etc), how can a maser be a primary standard? I > understand > that it can be an incredibly stable transfer standard but how can it be > considered a > constant?
Good question -- and that's exactly why masers are not primary standards. Instead, they have superb short- and mid-term stability so are useful as frequency (not time) standards for things like VLBI, or as "fly-wheels" for ensembles of cesium standards. In timing laboratories maser(s) and cesium(s) are often configured in essentially the same way as quartz and GPS are in a GPSDO: one provides stable short-term frequency and the other accurate long-term steering. /tvb _______________________________________________ time-nuts mailing list [email protected] https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
