Re: NEON- Re: Hg Injector

To: neon-l@lists.io.com
Subject: Re: NEON- Re: Hg Injector
From: marcus@ttphysik.uni-duisburg.de (Marcus Thielen)
Date: Fri, 25 Oct 1996 07:03:18 +0100 (MEZ)
In-Reply-To: <199610242205.SAA09548@smtp1.erols.com> from "Dilling" at Oct 24, 96 06:05:53 pm
Reply-To: neon-l@lists.io.com
Sender: owner-neon-l@io.com

Dear Matt,
 
> 
> This is also why blowing a tabulation hole in the middle of the piece can be
> useful. Anyone still
> do that? 

yes, sometimes, mostly when I couldn't find the right 'trode size 
in tubulated. 

> I have the hardest time when I have to get the blob of mercury buy
> an electrode with a mica shield...almost makes me whant to yank that little
> piece of mica out of the electrode. 

Keep on shakin' ! The tubes are stronger than most of us believe - when 
properly annealed. 

Or - use untubulated 'trodes only and attach a side tubulation about 1/2 
inch in front of the shell of one electrode. No optical disturbance, no
problems to get the drop in. 
 
> Lately 
> I have been just letting the mercury vaporize slower...Seems to me if there
> is a problem, and I cannot get the blob of mercury past the mica, could I
> not just put the tube back on the bombarder and give it a couple of seconds
> at .05-.01 to vaporize the mercury? 

NO NO NO, Same thing why the 'trodes must COOL DOWN before inserting the Hg.
When they're too hot coming in contact with liquid merc for the first time, 
the shell will get rough and and black. Ni- amalgam is formed immediately, 
giving a lower work function than pure Ni. This will lead to easy outside
discharge and sputtering, so reducing tube life. 

>  or is this a bad idea, and would I just
> reverse what I was trying to do and make the tube unevenly vaporized?
> 
> .  The amount of mercury placed in 
> >tubes varies considerably from bender to bender.  In most cases, the amount of 
> >mercury used is excessive but the biggest problem is consistently dispensing a 
> >"measured" amount of mercury.  The benefit of a good injector is placing the 
> >bender in precise control of the amount of mercury used.

Time on the ageing table is the best. Mercury vapour is heavier than argon, so 
placeing the tube flat or the already vaporized parts high can speed it up 
somewhat. Or put the whole unit in your kitchen oven at 80 Centigrades for
5 hours (imagine your wife's face). 

Marcus

References:

Re: NEON- Re: Hg Injector

From: Dilling <dilling@erols.com>