>>> 'lpe1' problem from bob -- Mon Nov  6 15:51:08 1989 <<<

The H2 purifier on lpe1 has been intitiated. It should be ready for
use in 1 hr.

>>> 'lpe1' problem from rosal -- Thu Nov 16 13:05:17 1989 <<<

I did a high temperature anneal (or bake out) to hopefully evaporate
impurities in lpe1.  I used teperature of 880C for 36 hours.  The 
boats were empty.  There was a good rate of hydrogen flow.
When I rolled the furnace away I noticed that the quartz tube had
turned green.  

The green color does not bother me (it is rather pretty), but it
indicates possible contamination.  I can use it as it is, since
I do not think it will affect my sample.  However, I should clean
it after I finish my runs, lest I provoke the wrath of higher
authorities in the lpe hierarchy.

The purpose of this "comment" is two fold.  First I want to make clear that 
I proceeded according to accepted practice, and did not do anything
out of the ordinary.  Secondly, since I have never cleaned a tube like
this, I want to ask how to do it.  I do not want any one to do it,
I just want information on how to do it.

Thanks,
respecfully,
rosa

>>> 'lpe1' problem from rosal -- Thu Nov 16 13:59:56 1989 <<<

this is a follow up on my previous comment.  Wei Hsin said that
there might be etching of the quartz, wich would weaken the tube,
and create a dangerous situation in case of rupture in a hydrogen
environment and high heat.  On the other hand, it might just be
contamination (some oxide of copper).

Would you please take a look at it?  I will not heat the tube
(I was going to melt some indium this evening-thursday) and hold
off until bob comes back to get the ok.  If it is not ok, then
a new tube will have to be ordered.  

I will be up at lbl tomorrow friday most of the day.  The phone 
number there is 486-4439.

Thanks,
rosa

>>> 'lpe1' problem from rosal -- Tue Nov 21 09:29:24 1989 <<<

I have entered this before, but gotten no reply.

I would like to know if it is safe to use the lpe by the wall
in the condition that is in (green powder on tube).  If it
is declared safe, I need to go ahead and use it, since I am
running out of alternatives for this proccesing step.

As I said before, I am willing to clean it, and I would
like some information on how to do it if this is available.

Thanks a lot,
rosa

>>> 'lpe1' problem from bob -- Tue Nov 21 10:57:30 1989 <<<

The green powder on lpe1 has been appearing since these machines were 
put online in 1968. It is Chromium Oxide and comes from the stainless
steel shell on the lpe furnace.

This reply was made earlier and the lpe1 problem deleted for our
equipment status board. It was likely glitched by me if it failed to
arrive.

lpe1 is up and useable.

>>> 'lpe1' problem from bob -- Mon Nov 27 15:25:58 1989 <<<

The H2 cylinders have been changed on the lpe furnaces.
There is currently 2200psi in the main regulator tanks and 2100 in the
reserve tank.
lpe1

>>> 'lpe1' problem from phillip -- Thu Dec 21 06:51:46 1989 <<<

1. Flow meter pulled off case.
2. Temp controller set to 1400dF. This WILL CAUSE A FIRE!!!!

>>> 'lpe1' problem from phillip -- Thu Dec 21 07:38:31 1989 <<<

The problem with the Matheson purifier is obviously
a thermocouple that has defected. This will be checked.

>>> 'lpe1' problem from phillip -- Mon Feb 26 11:15:25 1990 <<<

H2 gas status:
#1=2.0Kpsi   #2=2.1Kpsi   #3=1.8Kpsi
2 bottles in reserve.


>>> 'lpe1' fix from bob -- Fri Apr 27 15:41:32 1990 <<<

Gone!
