Thursday, June 16, 2016, 10:59

Previously sintered over weekend [see elog i.d 306]

Target container contains 450 discs of SiC [4 x 5 packs + 430 single discs]

Target packed length = 16cm. 

Mass of 533 discs SiC(green)  = 53.8758g

Container is wrapped with 3 heatshields; no end caps are inserted yet - coated spring inserted both sides to hold discs in place.

Conditioning temp = 1800C.

TGHT max = 710A according to sintering data.  TBHT max = 230A. 

Chamber is currently being pumped down. 

 Thursday, June 16, 2016, 15:43

Target was not removed from evap2 after sintering, vented and cleaned windows only.

HS water valves already open.

Stepped up manually to 70A, vacuum stable.

Initiated auto-ramp at 1.0A/min for the TGHT and 0.5A/min for the TBHT with max setpoints of 600A and 230A respectively.

TGHT = 118A, 0.9V

TBHT = 90A, 1.1V

IGP1 = 7.3e-7 Torr

 Friday, June 17, 2016, 12:14

TGHT has been tapped up manually to reach max desired temperature of 1800C

TGHT = 690A, 10.85V

TBHT = 230A, 3.88V

IGP1 = 4.9e-7 Torr

This is a lower current than the current required to reach 1800C during the sintering process.

For sintering, the max current was determined via extrapolation of trendline from raw data due to interference of coating on window and unable to take reliable readings from OMEGA.

For this conditioning process ~1800C is reached on the OMEGA since the window is still ~un-coated.

Will remain at 690A, ~1800C for several days to maximize conditioning process.

See attachment for raw data.

 Monday, June 20, 2016, 09:01

At the end of the day on friday 17th, OMEGA read ~1750C - no change in the current or voltage, vacuum was stable, this was the max setpoints used to reach 1800C.

This morning OMEGA = 2040C

TGHT = 690A, 10.95V

vacuum stable at IGP1 = 1.8e-7 Torr.

Slightly more noticeable coating on window port, looks like a thin ink layer, still relatively thin coating [ see attached image]

Also attached is archive from over wknd to show vacuum stable, current unchanged and voltage negligibly changed [only gone up by ~0.1V]

 Friday, June 24, 2016, 13:52

Container has remained at max setpoints for 7 days.

Initiating auto-cool for TGHT @ 2.0A/min and for TBHT @ 1.0A/min.

Will vent chamber and remove from evap2 to pass off for assembly monday morning.

See attachment for updated excel on temperature readings for the conditioning process.

 Monday, June 27, 2016, 08:28

vented in air and removed this morning.

target looks good!

all discs remained nicely alligned.

discs expanded outwards ~1cm, pushed back in to keep target length at 16cm

no visible yellow crystals like previous SiC targets 

endcaps inserted and expanded.

Rh foil inserted.

Ta heat shield foils removed, fins look good.

see photos attached for pictures of target - post conditioning.

coating on window very hard to remove. looked like a light sharpy pen coating on window. ended up scratching off with acetone and screw driver. couldn't remove all of it...