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.