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Message ID: 409     Entry time: Tuesday, May 08, 2018, 15:06
Author: John Wong 
Target Material: np-SiC 
Target Oven W.O#: Tube container  
Source:  
Status: Done 
Subject: NanoSiC thermal treatment batch#2 

Tuesday, May 08, 2018, 15:02

22 np-SiC fibrous discs loaded in the tube container (coated and sintered with TaC)

Heat treatment is similar to previous process, see elog #408. 

TGHT should be set at 330A/5.2V to reach temp 1575C (+/- 25).

Omega slope set at 1.05 (for carbide)

Chamber is currently being pumped down


 Tuesday, May 08, 2018, 22:46

Pressure at 2.2e-6 Torr.

Initiated autoramping at 0.2A/min to reach 330A


 Friday, May 11, 2018, 11:11

TGHT reached to 330A/5.1V but temp was measured at 1400A; It was held at that current for about 10 hours.

Increased TGHT to 335A/5.2V - temp is holding at 1420C (Will check the window if there is any coating that might have caused the discrepancy)


 Sunday, May 13, 2018, 00:25

In fact, the window is slightly coated.  The temperature should already be at optimum, 1600C.  Will keep heating for another day.


 Sunday, May 13, 2018, 14:10

Temp holding up well.. Pressure at 1.8e-7 torr. 

cooling down at 2A/min.


 Monday, May 14, 2018, 09:33

Target has been cooled for over 18 hours.  Pressure at 1.1e-7 Torr.

Venting chamber.

mass loss = (8.65 - 4.32)g = 4.33 g (50%) [slightly higher than expected, likely due to increase of 5A on TGHT]


 

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