[time-nuts] Hydrogen Maser KIT! Update #1

John Miles john at miles.io
Sun Nov 2 18:59:19 EST 2014

> >
> > Yes, but your Q will suffer.
> Ok, so it might / might not work depending on how high a Q it needs to start
> functioning. I think I might try it before I went crazy coating he bulb. There will
> be a *lot* of weird things to debug and associated tear downs to find them.
> Having a fragile bulb coating to deal with on top of everything else might just
> be more than can be dealt with.

With lower Q, you should still be able to get some usable discriminator action in passive mode.  In that scenario an external 1420 MHz pump signal is needed to maintain the stimulated-emission process while new H atoms are coming into the storage bulb.   I imagine you'll want to try that at first, in any event, just so you can observe the hardware actually doing something.  You should see some signs of frequency discrimination long before you observe self-sustaining radiation, if I understand the process right.

Once the line width is narrow enough, through a combination of the right inlet pressure, bulb coating, cavity Q, and intercession from St. Ramsey, thermal energy is enough to sustain the "chain reaction." In other words, photons from random spontaneous-emission occurrences will be retained in the cavity rather than lost, leading to coherent stimulated emission without any outside help.  But the odds of getting all of those factors right the first time don't seem good.

-- john, KE5FX
Miles Design LLC

More information about the time-nuts mailing list