Wednesday, April 14, 2021, 10:18

Work started to bring the ATTS PS inside the ITS HV cage. HV grounding rod and metal sheet around breaker panel were removed - see picture.

 Friday, April 16, 2021, Afternoon

HS line purged and turbos shut down.

Monday, April 19

Morning, Anders vented ITS

11AM, Dan found o-ring and indium seal on the same connector - likely this was the cause of the leak. replaced by a brand new indium seal, punched with the RH punchers, which seems the way to go.

Evening, Luca disinstalls FEBIAD from Fernando, and installs the P2N target. It has not been leak checked in the cold lab prior to installation (I'm not sure where all the equipment is), and no resistance measurements were carried out since I couldn't find Travis's ohm-meter.

Vacuum coming down, but slowly than I expected (took 1h to get from 2e-5 to 1e-5 T, is this right?)

Tuesday, April 20, 2021, 15:33

This morning Ray installed the controls cables connecting the ATTS PSs. They are still attached to the ATTS PLC, but their interlock signal now comes from the TBHT "enable" , through a 15V signal. Once the power is ON, he recommends checking that the TBHT sends the proper 15V (has to be higher than 12V) to the ATTS PLC, checking the voltage between the red and green/while cables on the PLC module labelled "TGHT:MAS". This should be done once the TBHT is "enabled", so the signal is sent.

The DC cables were installed going from the positive and negative poles of the ATTS:SLV. The order and number of 4/0 cables are:

Positive: One cable to G and two cables to E

Negative: One cable to H amd two cables to F

This should be checked with Arthur once he's on site (tomorrow).

A water leak was still seen, while the pressure was around 1E-6 T. Checking all three loops of FS#3, it's confirmed again that the leak is in HF. Will need top open up and pinpoint the leak.  

Thursday, April 22, 2021, 13:45

The lines F and G were inspected for water leaks. After blanking them to inspect the solder joint along the lines, two new indium seals were repositioned, the lines sniffed and no signs of leaks were detected. TS closed up again, pumping down now.

 Friday, April 23, 2021, 21:06

Pressure in ITS slowly coming down. This morning was ~3E-6T and now is 2E-6T. Water was flowing for most of the day, but I turned it off and purged FS#3 with no significant difference. I re-turned it on in order to run short PS tests with little current (up to ~10 A) for few seconds every time. Now I purged FS#3 again to leave the TS pumping over the weekend with air, so that opening the water in few hours/days might give us a better idea if the leak is still there.

As far as power supplies, we ran lots of tests today with Ray and Arthur (both were remotely connected through Teams). Initially the tests were unsuccesful because I kept turning off the main breaker when testing the electronics, and only later realized the ITS-PLC is connected to the same breaker.

After this realization, we progressed step by step: we confirmed that the enable signal (~13 V) was seen by both the ITS-TBHT and the ATTS-MASTER, however we realized that the ATTS:MASTER was *not* turning OFF when it should have. This is because the shutoff voltage signal was not zero, but was around ~1V, and was enough to turn OFF the TBHT (Xantrex) but not the ATTS:MASTER (TDK). Arthur suggested this could be due to the fact that two PLC are tied to each other, and see different "grounds", hence some voltage confusion might be coming from here. After taking a look at the connections in the ATTS PLC, we decided to try isolating the ATTS:MASTER module from its ground connection by disconnecting the yellow and green wires coming from the top of its PLC module, and this resolved the issue when the DB25 connector of the ATTS"MASTER is disconnected from the PS; however, once this DB25 is connected, the voltage seen by the MASTER is still ~1V and not zero, and still enables the PS when it should instead be shutoff. 

Next week we should try to find the proper wire configuration that allows seeing zero V as shutdown signal and not ~1V.   

Tuesday, April 27, 2021, 20:56

The new P2NHT power supply configuration is now operational at the test stand. A relay was added in the PLC cabinet to take a +15V signal from the TBHT PLC module and close a short circuit to "enable" the P2NHT master and slave (TDK-LAMBDA).

After initial ramping up to ~222A, I noticed the voltage read by the PS was about 0.45V, while extrapolating the results from the previous ITS-P2N run, the voltage should have been ~0.9V. I would like to measure the resistances of the lines to pick up potential shorts in the copper conductors in the vacuum chamber.  

Wednesday, April 28, 2021, 11:30 

This morning, the resistance matrix was measured between the feedthroughs of the test stand, see attached picture.   

TBHT+ = A

TBHT- = B

P2NM- = C

P2NM+ = D

P2NS+ = G,E

P2NS- = F,H

Talking to Carla, we agree that the matrix seems correct and does not show any signs of short in the lines. But still, the voltages read by the PS seem too low compared to the previous run on July 2020.

Wednesday, April 28, 2021, 19:14

To make sure that current is not flowing where it is not supposed to be, the ion source only (A, B) was hooked up  to the TBHT

Voltages: 

A/C (TBHT+ / P2NM-)=-0.11 V

A/D (TBHT+ / P2NM+)=-0.11 V

B/C (TBHT- / P2NM-)=0.21 V

A/B (TBHT+ / TBHT-) = 0.33 V

While the PS reads 0.42 V --> The two lines made up by two welding cables each make up for the remaining 0.09 V

There's no current flowing anywhere else, all other feedthrough have V=0 between each other.

Wednesday, April 28, 2021, 20:01

Welding cables attached so that the P2NM and P2NS only (TGHT and COIL) are delivering current to the target.  

At 230A of the P2N heater (130 on the master, 102 on the slave), the sum of all current coming and going to the feedthroughs balances out. 

The voltages across feedthroughs make sense:

B/C (TBHT+ / P2NM-)= 0.20 V

B/D (TBHT+ / P2NM+)=0.22 V

A/B (TBHT+ / TBHT-) = 0.0 V

C/D (P2NM- / P2NM+) = 0.44 V

E/C (P2NS+/P2NM-) = 0.46V

The current going from I (HV common) to H (P2NS-) is zero (0.3A)

After checking these values, I see no reasons to believe the wiring is incorrect, and will proceed with the full installation of P2N heater and TBHT, and ramping up the whole system together. It was noticed though that the TBHT cannot be ramped automatically since the ITS TGHT is not connected to the PLC, and needs to be ramped by hand.