Monday, June 12, 2017, 11:41
UO2/C green was prepared June 7th, 2017.
The cast peeled off the glass nicely June 8th, 2017.
Initial UO2 powder used = 50.10g (Inventory R-01032A, UO2 + bottle = 776.36g before use)
Graphite powder used = 10.06g
Green cast dried UO2/C + organic mass = 62.98g
The green was rolled up and wrapped in a piece of graphite sheet.
The Ta-target boat was wrapped with 1 long layer of heat shield [reused from last carbonization] and installed in evap1 this morning.
Chamber pumped down.
Target boat will be ramped up to 520A.
Vacuum limit stop at 5.0e-5 Torr, backing off at 6.0e-5 Torr.
IG1 = 1.58e-5 Torr
Tapped up to 30A, 0.21V
Waited ~1hr45, vacuum stable.
IG1 = 8.59e-6 Torr
Initiating auto-ramp at 0.1A/min
Tuesday, June 13, 2017, 10:32
IG1 = 5.0e-5 Torr
TGHT = 65A, 0.47V
Vacuum currently yo-yo-ing, but stable.
Changing vacuum limits.
Vacuum limit stop at 2.0e-4 Torr, backing off at 5.0e-4 Torr.
Increasing ramping rate to 0.2A/min.
Thursday, June 15, 2017, 16:24
IG1 = 1.96e-4 Torr
TGHT = 520A, 5.18V
TGHT has reached 520A, the vacuum remains at it's limit.
Vacuum usually drops and stabilizes slightly before the max setpoint is reached indicating carbonization process complete.
Since vacuum remains high, this indicates the carbonization remains incomplete.
Conditions have changed such as vacuum limits, which has greatly sped up the process.
This increase in speed could have an impact on the current at which the carbonization occurs.
Increasing max setpoint to 530A and re-initiating auto-ramp.
Friday, June 16, 2017, 08:32
Vacuum stable, started decreasing when TGHT reached 530A - carbonization process complete.
Evap1 has remained at max setpoints for ~11hrs, but has remained at low vacuum for ~5hrs.
IG1 = 5.56e-6 Torr
TGHT = 530A, 5.31V
Initiating auto-cool at 1.0A/min
TP = 24.9C, RT = 24.3C
*note TP now has water cooling as well as fan pointed at it for this entire process
Monday, June 19, 2017, 16:16
Vented in Ar and transferred from evap1 to glove box this a.m
UC2 flakes produced = 48.66g
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