[time-nuts] It is possible to "recharge" a hydrogen maser?

[Luiz Paulo Damaceno]

Thank you for the experience / instruction!

Em ter, 9 de jul de 2019 12:05, <cdelect at juno.com> escreveu:

> Luiz,
> Ch1-75 Hydrogen storage details.
>  “The compound LaNi5H, is used for storing molecular hydrogen.
> The LaHi5H, is characterized by high hydrogen partial pressure (2 to 5
> atmospheres) at +(20-50) degrees C.
> 250 grams of the compound contains 18 liters of hydrogen at normal
> pressure.
> It is sufficient for maser continuous operation for more than 40 000
> hours.”
>  I believe that the container holding the LaHi5H is heated and
> thermostatically controlled to maintain the proper pressure into the
> purifier.
>  First you should be able to power up the maser just far enough so that
> the ion pumps can operate. Monitor their current and it should drop down
> to almost zero within a few hours. If not you may need to get the ion
> pumps rebuilt.
> There are commercial outfits that can rebuild them but if there are not
> isolation valves to close and isolate the Maser when you remove the ion
> pumps you will not be able to proceed! Since the Russian Masers also use
> a getter pump in concert with the ion pumps, opening up the vacuum system
> will contaminate the getter pump. The process of clearing the getter is
> very detailed and involves temperatures of up to 800 degrees C, and
> without careful instructions on how to do it you risk damaging other
> portions of the Maser!
>  If the pressure does drop down, then you need to determine if there is
> any Hydrogen left. I know that some Russian Masers will give you an alarm
> that tells you if you are out, and some have a mechanical pressure gage,
> but I’m not sure about the CH1-75. You will need to check the manuals. If
> it does not provide an alarm or have a gage then see if the HFO
> oscillator is working and if the discharge bulb is lighting up. If it
> lights up you are not out of Hydrogen!
> If it does not light and you have determined that the  lack of Hydrogen
> is indeed the problem you will need to locate the LaHi5H container. After
> you locate it make sure it is being heated, this could cause an apparent
> lack of Hydrogen!   Then see how it is connected to the discharge bulb.
> Hopefully it will be a threaded connection. This connection is on the
> high pressure side of the purifier and can be removed without
> compromising the vacuum. You will need to remove the container and
> recharge it.  I would instead replace it with a small compressed hydrogen
> cylinder and regulators.
>  Use ultra-high purity dry Hydrogen and make sure you purge the line
> going to the purifier. The purifier will block other gases from getting
> into the Maser but in the process too much “foreign” gas can contaminate
> and damage the purifier!
>  Once you manage to locate the container some pictures on where it’s
> hiding would be nice!
>  Good luck with your efforts!
>  Cheers,
>  Corby Dawson
> _______________________________________________
> time-nuts mailing list -- time-nuts at lists.febo.com
> To unsubscribe, go to
> http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com
> and follow the instructions there.
>