Monday, August 12, 2024, 17:00   EOD. target installed, roughed, turbos on. No effect on vacuum from turning on water cooling lines. TGHT TBHT slowly brought to 230A/230A overnight. 

Tuesday, August 13, 2024, 09:28.  Vacuum at 9.9e-7T.  TGHT TBHT at 210/210. accelerating heating to 230/230. bringing up HV EZL EE to 30 / 2.5 / 13   kV

Tuesday, August 13, 2024, 09:51.  with EZL 13kV, EE 2.5kV. When increasing BIAS from 17.0 to 17.5kV.  Signal becomes detectable on FC0, at 7.75e-10A

Tuesday, August 13, 2024, 10:13  at BIAS 30kV. FC0 and wire scanners appear to be working correctly. FC0 reading 2.66e-8A 

Tuesday, August 13, 2024, 10:13  turning on all beam optics for FC6 mass scan.

 Tuesday, August 13, 2024, 10:31   mass scan procedure is doing a very poor job of recording the background noise. filename  2024-08-13_10-44 Ksalt mm 230-230

Tuesday, August 13, 2024, 10:46   increasing tght to 330

Tuesday, August 13, 2024, 10:59    FC0 at 2.1e-8A

Tuesday, August 13, 2024, 11:12  running mass scan at TGHT TBHT = 330/230 A.   filename 2024-08-13_11-21 Ksalt mm 330-230

Tuesday, August 13, 2024, 11:23 increasing TGHT to 430

Tuesday, August 13, 2024, 11:29  three sparks within 2 min at TGHT 378A.  (no sparks at all previous to this). TGHT ramp aborted. 

Tuesday, August 13, 2024, 11:36  resuming TGHT increase after 6 minutes of no sparks.  

Tuesday, August 13, 2024, 11:51  FC0 reading 1.6e-8.  FC0 signal fluctuating throughout test. rises during ramp and drops during static TGHT TBHT level.

Tuesday, August 13, 2024, 11:53  running mass scan at TGHT TBHT 430/230 A .  filename 2024-08-13_12-16 Ksalt mm 430-230 

Tuesday, August 13, 2024, 12:17  increasing TGHT to 530A.  

Tuesday, August 13, 2024, 12:31  FC0 at 3.03e-8 A

Tuesday, August 13, 2024, 12:31  beginning mass scan   -  filename   2024-08-13_13-02 Ksalt mm 530-230

Tuesday, August 13, 2024, 13:02 increasing TGHT to 580A 

Tuesday, August 13, 2024, 13:13   FC0 at 3.58e-8A.  beginning mass scan - filename  2024-08-13_13-35 Ksalt mm 580-230

Tuesday, August 13, 2024, 13:37    increasing bias to test sparking

Tuesday, August 13, 2024, 13:58   at 37kV, a number of optics elements prior to FC0 went down. no voltage or current spikes

Tuesday, August 13, 2024, 13:59  at 42.4kV, a couple sparks, seem to involve TGHT and BIAS. these dropped a few optics elements. when I brought them back up, they went down again, at a time with no voltage or current spikes.

Tuesday, August 13, 2024, 14:30 at 43.6kV, the sparking frequency became regular, with HV bias sparks occurring approximately every 5 minutes

Tuesday, August 13, 2024, 17:00 considerable time was spent until end of day manipulating the bias and the TGHT current level in an effort to discover the location of the regular sparking

increases in HV were found to increase the frequency of sparking, and eventually the HV increase was found to hit a threshold where the current would increase noticeably, with a stable voltage. this was accompanied by a buzzing coming from the feedthroughs on top of the cage. seemed to be coming from the TGHT(+) feedthrough. At no time did there appear to be sparking within the chamber of the test stand. In one instance, with HV just below the threshold of buzzing, increasing TGHT seemed to induce the buzzing state.

Wednesday, August 14, 2024, 11:16  ramping up bias to HV. intending to push HV today to find the source of these sparks and buzzing. initially, will be observing this with TGHT TBHT at 180/180 A

Wednesday, August 14, 2024, 11:47 at BIAS = 32.6kV (with EE 2.5 kV and EZL 13 kV), HV appears to be stable. Yesterday, we observed a fluctuating BIAS current which seemed to culminate in regular sparking activity (although this was at voltages of >40kV)

 Wednesday, August 14, 2024, 12:26 at bias = 38.8kV, there was a significant accompanying increase in BIAS current, but no evidence of sparking or buzzing

 Wednesday, August 14, 2024, 12:46  at BIAS = 49.2kV, the buzzing begins.  On the strip tool this is also seen as a large jump in current, with stable voltage

Wednesday, August 14, 2024, 12:49  dropping the bias by ~1kV stopped the buzzing. ramping up quickly again caused a spark and more buzzing.  increasing the voltage to attempt to locate the source.

Wednesday, August 14, 2024, 13:18   at bias of 49.2kV, buzzing began. dropping the bias stopped it. to attempt to locate the source, we increased the bias significantly. At 53kV, the bias power supply began to current limit. when this was increased, a spark caused the putty connection at the test stand to disconnect and two turbo pumps to trip off. once restored, another increase of the bias eventually caused a large spark when trying to locate the buzzing sound. Again, it seems to be at the feedthroughs of TGHT TBHT. My guess is TGHT+, but there is nothing visual to confirm it is coming from there. This buzzing state is also accompanied by a drop in EZL current to 0 and a large increase in EZL voltage readback.

 Wednesday, August 14, 2024, 15:05 dropped the HV and removed the cage to investigate any issues. we propose that this likely involves jumping to the einzel lens and are curious if raising the EZL voltage significantly would prevent this state from recurring. cage back on, raising HV

Resuming testing after TGHT TBHT power supply updates:

Friday, September 06, 2024, 12:09:   Ramped up TGHT and TBHT to ~170A at 1A/30s.  Increasing ramp rate to 1.7A/10s up to 580A/230A

 Friday, September 06, 2024, 14:11  slowly increasing BIAS, EE and EZL to 30kV, 2.5kV, 13kV

Friday, September 06, 2024, 15:53  appears that FC0 and wire scanners are working normally. However, there is a threshold reading problem with FC6. seems that a negative readout is present on FC6 if there is no substantial signal, and then nothing is recorded to the mass scans.

Friday, September 06, 2024, 15:54  increasing voltage to test high voltage sparking (BIAS AND EZL)

Friday, September 06, 2024, 16:23  after resetting the FC6 polarity and the FC6 bias, the background signal began showing up.

Tuesday, September 10, 2024, 12:19  Test stand vented, target removed.