[time-nuts] Maximizing Cs Tube Life

[Tom Van Baak]

> "The candle that burns twice as bright,  burns half as long..."

I've heard, but have not verified myself, that 5071A
high-performance tubes will last at least 7 years of
continuous use and that 5071A standard-performance
tubes can last around 20 years.

For high-perf tubes end-of-life is usually due to running
out of cesium. For standard-tubes the lifetime may be
more limited by degradation of the electron multiplier than
running out of cesium.

I don't have specific information on oven temperatures,
beam flux, ion velocity, EM gain, etc. so don't draw too
many conclusions from the 7 vs. 20 number. If someone
has more complete information that would be helpful.

The question about tube life for those of us with surplus
cesium standards is not simple -- over the decades there
have been several cesium tube manufacturers (hp/Agilent,
FTS/Datum, FEI) each with several product generations
or models.

Thanks,
/tvb