Laura Lambert wrote:

Laura Lambert wrote: Laura Lambert wrote: Laura Lambert wrote:  Wednesday, July 12, 2017, 17:06 Target container was previously coated with TaC and sintered. Container is wrapped with 3 layers of Ta-heat shield, including the center block The target consists of 400 discs of UCx with 13.60cm in length [8 packs of 5 + 360 single discs/ 2.6cm on left side, 2.8cm on right side wrt ionizer into page]. Discs in target are arranged as follows: 1pack / 60singles / 1pack / 60singles / 1pack / 60singles / 2packs / 60singles / 1pack / 60singles / 1pack / 60singles / 1pack A regular TaC coated endcap is inserted left, wrt the ionizer tube pointing down. The right side is open with a TaC coated spring to help hold materials in. The chamber is currently pumping down. TGHT will be ramped up to 450A at 0.1A/min [same current used to reach 1900C in evap2 when sintering TaC coating - elog373 evap2] Parameter setup: 5.0e-5 good vac, 6.0e-5 bad vac. Thursday, July 13, 2017, 12:49 Tapped up manually to 35A. Waited ~2hrs, vacuum stable: IG1 = 2.64e-6 Torr Initiating auto-ramp.    Thursday, July 13, 2017, 14:48 Update: auto-ramp not started. With recent updates to evap1 epics, not everything was uploaded correctly. TGHT auto-ramp system not working: parameter boxes have white outline indicating locked. No parameters can be inputed and therefore unable to start auto-ramp.  Friday, July 14, 2017, 15:56 Problems still not fixed. Have tapped up manually to 50A, 0.59V Vacuum stable; IG1 = 5.26e-6 Torr. Will remain at setpoints over weekend before continuing to ramp up manually...  Monday, July 17, 2017, 15:10 New problems: Paddle wheels for evap2 need replacing asap [see elog evap2 i.d.378] In order to replace, supply/ return need to be turned off and a full purge; therefore, evap1 must be off otherwise it will trip off from no water. Evap2 needs to be fixed asap and cannot wait for this process to be complete. Evap1 had been tapped up manually to 60A. Tapping down manually to 0A so one can start the paddle wheel replacement work tomorrow.  Tuesday, July 18, 2017, 15:31 Paddle wheels for evap2 replaced and up and running again. IG1 = 1.2e-6 Torr. Starting to tap back-up manually...    Wednesday, July 19, 2017, 14:12 TGHT auto-ramp fixed. Since TBHT isn't hooked up yet, epics thinks TBHT has tripped off. Currently during auto-ramp, every time steps up: states TBHT tripped off. This is not the case but not a big deal as we will soon have TBHT hooked up and this won't be an issue. Also it only states it, doesn't stop auto-ramp and therefore technically works fine/ will go with this for now... Note: Might be a few spikes on striptool from past hour when IOC was rebooted.    Wednesday, July 19, 2017, 14:16 Tapped up manually to 30A yesterday. Continued manual tap up today and reached 60A. Initiated auto-ramp. IG1 = 4.4e-6 Torr

 Thursday, July 20, 2017, 14:48

TGHT tripped off yesterday evening 

Auto-ramping was fixed but a few more glitches in the system caused the TGHT to trip.

Please refer to photos.

When auto-ramp is running and vacuum reaches the parameter set for 'Good Vacuum', the auto-ramp should stop until the vacuum drops below the good vacuum at which point it can then continue to auto-ramp.

When auto-ramp is running and vacuum reaches the parameter set for 'Bad Vacuum', the auto-ramp should initiate auto-cool/ramp-down until the vacuum drops to the good vacuum parameter at which point it can then proceed with the 'Good Vacuum' requirement.

With this scenario, the auto-ramp system ignored the parameters set for good and bad vacuum, proceeded past both points and continued to ramp until the vacuum eventually reached it's trip off vacuum causing the TGHT to trip.

The TGHT current was at ~90A when it tripped off, so the target should be OK.