See e-log entry: 884:

Thursday, February 04, 2021, 18:45: Roughing

Thursday, February 04, 2021, 19:13: Turbos on.

Thursday, February 04, 2021, 19:22: IG1 on.

AS

Friday, February 05, 2021, 06:20: Waterline FS#5 open. Vacuum ok @ 1.71e-06T.

Friday, February 05, 2021, 06:23:

Friday, February 05, 2021, 06:26: Tried to put 100 - 1000 V on the BIAS. Goes to 0.0 kV - BIAS:RDVOL / 0.029 mA - BIAS:RDCUR, straight to current limit. BIAS is shorted.

Friday, February 05, 2021, 06:32: Power / Sources / Optics off. Ion gauge & Turbo pumps off.

Friday, February 05, 2021, 07:28: Venting.

Friday, February 05, 2021, 08:37: Roughing. Target was re-salted. GE line was close/light touch to (B) line. Adjusted. Waterlines open on FS#5.

Friday, February 05, 2021, 09:06; Turbo pump TP1B on.

Friday, February 05, 2021, 09:14: Turbo pump TP1A on

Friday, February 05, 2021, 09:19: TP1A tripped. Wait on backing pressure.

Friday, February 05, 2021, 09:35: Vacuum Bypass on BV1A to turn on TP1A.

Friday, February 05, 2021, 09:39: TP1A at speed. Ion gauge on. Bypass removed.

Friday, February 05, 2021, 09:55: IG1 off. Bypass used on IG1. EE on, BIAS on.

Friday, February 05, 2021, 09:56: 500 - 1000 V - BIAS:RDVOL / 0.000 mA - BIAS:RDCUR. Ok.

Friday, February 05, 2021, 09:58: BIAS & EE off. Bypass removed. IG1 back on. Initial check ok. Vacuum to go below 1.0e-05T.

Friday, February 05, 2021, 11:37: Power / Sources / Optics on & set. Vacuum @ 6.46e-06T.

Friday, February 05, 2021, 11:42: BIAS / EE / EZL @ 10 / -1.0 / 7.5 kV

Friday, February 05, 2021, 11:50: BIAS / EE / EZL @ 20 / -1.5 / 13 kV. TGHT / TBHT @ 10 / 10 A.

Friday, February 05, 2021, 11:58: BIAS / EE / EZL @ 25 / -1.5 / 13 kV. TGHT / TBHT @ 10 / 10 A. Anode checked up to 100 V & down again. Ok.

Friday, February 05, 2021, 12:06: BIAS / EE / EZL @ 30 / -1.5 / 13 kV. TGHT / TBHT @ 10 / 10 A.

Friday, February 05, 2021, 12:14: BIAS / EE / EZL @ 35 / -1.5 / 13.5 kV. TGHT / TBHT @ 10 / 10 A.

Friday, February 05, 2021, 12:24: It charged up and began sparking continuously around 12:23.

Friday, February 05, 2021, 12:33: BIAS / EE / EZL @ 15 / -1.0 / 10 kV. TGHT / TBHT @ 10 / 10 A. The sparks were both clearly audible & visible on the spark gap up top (Image to be included in word doc)

FM

Friday, February 05, 2021, 14:16:   BIAS / EE / EZL @ 30/ -1.5 / 13 kV.  Anode @ 50 V.

Friday, February 05, 2021, 14:18: Auto ramp-up TGHT/TBHT to 580/230 A @ 4A/min

Friday, February 05, 2021, 15:08: Anode shorted, I think the  tube heater is touching the plasma electrode. TGHT/TBHT @ 209/209 A. TBHT voltage= 2.2. At the same time the bias current jump from 0.008 to 0.01.

Friday, February 05, 2021, 15:12: Reducing the TBHT to 190 A 2 V. Bias current linearly reducing with tbht current. The cathode is not current limited anymore. Wondering if the TBHT power supply is causing an electrical backflow or if the ion source is touching the plasma electrode.

Friday, February 05, 2021, 15:16: Auto ramp-up TGHT/TBHT to 580/230 A @  2 A/min

Friday, February 05, 2021, 15:21: The same effect as before at TBHT=223 A. When reducing to 190 A, anode goes up. 

Friday, February 05, 2021, 15:30:  Auto ramp-up TGHT to 580 A @ 4A/min and TBHT to 230 @ 1 A/min. 

Friday, February 05, 2021, 15:55: Sparks, not audible nor visible. I think I saw one on the top part of the water blocks. Lowering bias to 10 kV.

Friday, February 05, 2021, 15:56 : Auto-ramp range to 4A/min on both TGHT and TBHT

Friday, February 05, 2021, 19:23:  almost 2.5 hours without sparks. RPM tests performed. Voltages to zero. Will rise later or tomorrow remotely.

Taped down to 180/500 A on TBHT/TGHT. All voltages to  BIAS / EE / EZL @ 0.000 kV.

Saturday, February 06, 2021, 11:14:   Auto ramp-up TGHT/TBHT to 580/230 A @ 4A/min

Saturday, February 06, 2021, 12:16:    BIAS / EE / EZL @ 30/ 1.5 / 0kV.  

Saturday, February 06, 2021, 12:30: The previous tune is not working anymore. I have to re-tune . EZL now helps to have a better tune, no need for extreme steering

Well well well, after several scans I observed the following:

• Bias readback changes by 14  V. This doesn't necessarily means this is the absolute value, it could be better or worse.
• Magnet oscillates around 1 gauss, enough to move the beam to the sides.
• Different settings on the rpm scans does not yield to different results in the data
• Intensity variations causes one of the rpms scans to be lower or higher.
• Total source scans are always mirrored as long as nothing else varies.
• Separated ion scans varied wildly. No two consecutive scans are the same. Likely a combination of Bias voltage and magnet current ripples.
• Following Baartman's proceedure on a cherry-picked data set, I estimated an energy spread of 11.75 eV. To be discussed with him

Saturday, February 06, 2021, 20:00 Biases to 0.000 kV

Saturday, February 06, 2021, 20:00 : Auto-cooling TGHT/TBHT  to  400/150 A @ 3 A/min

 Saturday, February 06, 2021, 21:02: On the way down, TBHT 150  A and when TGHT cross 480 A the anode came back to life. Wonder if this could help diagnose deflection on the surface ion source (might be helpful for the P2N)

Sunday, February 07, 2021, 08:26:  Auto ramp-up TGHT/TBHT to 560/210 A @ 2A/min

Sunday, February 07, 2021, 09:18: Anode got current limited again when TGHT/TBHT @ 446/200 A 

Sunday, February 07, 2021, 11:26:  Auto ramp-up TGHT/TBHT to 560/210 A @ 2A/min 

 Sunday, February 07, 2021, 11:31: Once again, the latest tune did not work. I suspect the ion source deformation varied from thermal cycle to thermal cycle. With a crooked beam, the EZL will send the beam off-center and the quad will not compensate that. The double peak observed in the beam size scan indicates that the focusing is not correct.

Sunday, February 07, 2021, 18:41: With Baartman RPM scans, the x axis in in cm, as verified with an emittance scan.

New parameters on the emittance rig for this tune. Offset from 40 to -50. This shifts the phase space in the y axis such that is visible on the plot. 

Even in a different mass, the position scans on the dispersion plan are not reproducible.

Sunday, February 07, 2021, 18:52: Auto-cooling TGHT/TBHT to 400/150 A  @ 6A/min / 3 A/min, respectively.

 Sunday, February 07, 2021, 18:53: Biases to 0.000 kV

I think the fast cool-down rate prevented the TBHTto be able to sustained voltage.

Sunday, February 07, 2021, 19:35: Auto-cooling TGHT/TBHT to 0 A @ 3A/min 

TBHT able to sustain voltage once TBHT=191 A and TGHT=372 A

Monday, February 08, 2021, 07:14: IV4 close

Monday, February 08, 2021, 07:15: IG1 off. Turbos off.