Monday, July 10, 2017, 17:28
Two np-SiC fibrous pellets with different applied pressure:
1) 200MPa, 2) 335 MPa (see logbook pg 36 for more details).
Desired heating temperature: 1550C (Previous setting: TGHT 400A/6.94V)
Two layers of Ta foils wrapped around the target boat.
Chamber is pumping down...
Tuesday, July 11, 2017, 11:11
Pressured came down to 1.0e-6 Torr.
Tapping up TGHT.
Tuesday, July 11, 2017, 11:24
Tapped TGHT up to 45A - pressure stabilized at around 3.0e-5 Torr.
Auto ramp 1.0A/min to reach 350A before tapping up further.
Wednesday, July 12, 2017, 10:59
TGHT reached to 350A/5.5V, temp @ 1270C - much lower than expected; could be a short between the target container and the heat shield. I actually had a had time adjusting the target legs to avoid shorting the cu-heat shield.
Tapped TGHT further up to 375A/6.07V, Omega Temp at 1340C. Holding current for about 50 mins, re-measured with pyrometer - temperature matches.
Wednesday, July 12, 2017, 14:49
TGHT set at 450A/7.7A. Temp at ~1550C. See attachment for temp plot
Holding at temp for 5 days before cooling down on Monday July 17.
Thursday, July 13, 2017, 17:52
TGHT tripped off due to bad IEVAP2:WFB1 water flow. Not sure what was the cause. Will leave the heater off for now and investigate this tomorrow.
Friday, July 14, 2017, 11:48
Investigated the bad water flow situation. It was due to a faulty water flow sensor. The paddle wheel stopped turning until I gave it a tab. We had a similar problem before with the water sensor, see elog ID 109. It is probably the time to replace all the water sensors.
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