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Entry  Thursday, March 29, 2012, 19:30, Nikita Bernier, BeO, Target boat #1, , Done, Sintering new BeO pellets 
    Reply  Thursday, March 29, 2012, 22:44, John Wong, BeO, Target boat #1, , Done, Sintering new BeO pellets Parameter.jpg
       Reply  Friday, March 30, 2012, 23:21, John Wong, BeO, Target boat #1, , Done, Sintering new BeO pellets archive_24hr.jpgTGHT@240A.jpgTGHT@700A.jpgTGHT@750A.jpgTGHT@0A.jpg
          Reply  Monday, April 02, 2012, 16:26, Nikita Bernier, BeO, Target boat #1, , Done, Sintering new BeO pellets 
Message ID: 13     Entry time: Friday, March 30, 2012, 23:21     In reply to: 12     Reply to this: 14
Author: John Wong 
Target Material: BeO 
Target Oven W.O#: Target boat #1 
Source:  
Status: Done 
Subject: Sintering new BeO pellets 

John Wong wrote:

Nikita Bernier wrote:

 Thursday, March 29, 2012, 19:17

 

Target boat contains 3 BeO pellets :

Sample,   Thickness (mm),   Mass (g),  Density (g/cm3)

1    9.06,  1.9713,  1.413

2    9.11,  1.9900,  1.416

3  13.54,  1.9916,  0.956

 

Samples 1 and 2 are made of BeO powder with 30% PVB which was washed with excess acetone and let to dry on a greased baking sheet (with PAM Butter flavoured). The flakes were then milled for 26 minutes at 400 RPM. It resulted in a very fine grey powder, much denser than the BeO powder with 30% PVB (not washed with acetone) that was used for Sample 3.

The initial settings on Evaporator #2 were 100 A and 0.83 V until the vacuum increased.

Evaporator #2 is now auto-ramping overnight at 1 A/min, up to 700 A, with the maximum voltage limited at 14 V, between 5.00e-05 (Good vacuum) and 6.00e-05 Torr (Bad vacuum).

 

 

 

 Thursday, March 29, 2012, 22:31:

TGHT tripped off a few times over the past hours.  After changing the Good Vac to 2.00e-5 torr and Bad Vac to 3.00e-5 Torr, the target heater are regulating properly and the max pressure is well maintained below 6.5e-5 Torr [Trip point @ 8.0e-5 Torr].  (see attachment#1: parameter.jpg)

Friday, March 30, 2012, 23:19  

Archive of the target current and vacuum over the past 24 hours.  (see attachment #1: archive_24hr)


Saturday, March 31, 2012, 12:12

The organic materials have been burnt off.  The target heater ramping up is no longer restricted by the vacuum limit. 

Archive of the target current and vacuum over the past 10 hours. (see attachment #2: TGHT@240A). 


 Saturday, March 31, 2012, 22:52

TGHT has stayed at 700A/12.37V, local @ 693A/12.43 = Temp @ 1780C.  

The striptool shows some out-gassing when TGHT reached to 700A. (see attachment #3 marked with black circle: TGHT@700A.jpg)

Increasing TGHT to 750A to see if there is any further reaction...  


Sunday, April 01, 2012, 10:24  

TGHT was ramped up to 750A, local 730A/13.90V.  The pressure has come down to low 10e-6 but not stable;  Some reaction may be ongoing therefore it's causing the vacuum excursion.  (See attachment #4: TGHT @ 750A).  Notice the current readback is not constant and it's slowly decreasing as the voltage readback is increasing.  There might be some resistant building up.

--> Initiating the cool-down process at 2A/min. 


Sunday, April 01, 2012, 19:30  

TGHT has ramped down to 0A, and the pressure is going down (currently at 7.e-8 Torr) with no excursion.  (see attachment #5: TGHT@0A). 

The chamber will be vented tomorrow, and the target materials will be inspected. 


 

Attachment 1: archive_24hr.jpg  24 kB  | Show | Hide all
Attachment 2: TGHT@240A.jpg  37 kB  Uploaded Saturday, March 31, 2012, 13:17  | Show | Hide all
Attachment 3: TGHT@700A.jpg  135 kB  Uploaded Sunday, April 01, 2012, 00:00  | Hide | Hide all
TGHT@700A.jpg
Attachment 4: TGHT@750A.jpg  51 kB  Uploaded Sunday, April 01, 2012, 11:28  | Show | Hide all
Attachment 5: TGHT@0A.jpg  32 kB  Uploaded Sunday, April 01, 2012, 20:30  | Show | Hide all
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