[time-nuts] Maser manual

[Bruce Griffiths]

Attila Kinali wrote:
> On Wed, 01 Sep 2010 20:08:13 +0000
> "Poul-Henning Kamp"<phk at phk.freebsd.dk>  wrote:
>
>    
>>> Yes, but what is the issues relating to sapphire loading? What's the
>>> cost of the sapphire block and having it machined?
>>>        
>> It is a saphire tube, a readily available, if not exactly cheap, commodity.
>>      
> Why saphir? Aluminia (AlO2) seems to be used as well to load H maser
> cavities. Or is saphir in some way better?
>
> 				Attila Kinali
>    

Sapphire and ruby are slightly impure varieties of corundum the single 
crystal form of aluminium oxide.
Sapphire and rubies just have different inpurities that impart colour to 
the gem.

The microwave loss in single crystal alumina (sapphire, corundum) may be 
somewhat lower than for the polycrystalline form.

Bruce