One thing that seems to be strange regarding this FEBIAD is the best results are without any current in the coil.

Normally for the neon ionization the on-line source wanted to be at around 50 to 80 Amp. Not this one.

Is there anything special about this coil?

Ray is finishing the electrical modifications for the FEBIAD with the biased cathode.

We found the source of the sparks. The disconnected target heater cables were resting on the Einzel lens cap.

Yesterday Ray Dube has changed the configuration in order to run the FEBIAD with the cathode on negative bias.

There were a short between the gas line and the common. The box has been opened and the short removed.

This morning I am turning on the cathode heater to 290 A.

Backing pressure on the bender section is quite large. TMSIG6 reads 5.09E-7 T and TMS:CG2B reads 0.249 T!

Test completed.

exel file on My Documents in folder FEBIAD Test Aout2012/TestFEBIAD

 Edited by Anders 2012-09-19, file attached.

HV conditioning has begins. Vacuum chamber pressure is currently 3.2e-07 Torr on TSG:IG1.

I opened the test stand because I forgot to install tantalum heat shields around the target. Everything was reinstalled as before (with heat shields). I could turn on the TSGTP1B but TSGTP1A does not turn on for some reason. I tried multiple times opening/closing its valve (BV1A) but the pump never starts.

Will keep pumping over the weekend with TP1B only.

(see entry 742)

p2n target heated over the weekend after the connections between the bottom target legs and the copper connector has been modified from rivets to M3 screws. Target hold current nicely with no major voltage spikes.

The plan now is to cycle the current heating few times to "stress test" the target.

Friday. July 26th 2019 

A new electrical configuration of the test stand was decided and installed. The TGHT and TBHT were parallelized in order to deliver up to 600 + 600 Amperes to the p2n target.

Connections:

TGHT+: D

TGHT-: C

TBHT+: one cable to E and one cable to G (both going down to the coil terminal blocks, which are connected to the target terminal blocks through a copper short.

TBHT-: both cables to F. One 4/0 cable was run from F to H to achieve the same configuration as for TBHT+. The H terminal is connected to I (HV ground, conencted to the target copper heat shield) through a braided cable

One braided cable was connected from C to H so the target line should have the same potential as the TBHT/coil lines.

Saturday, July 27th

The current was ramped from the TBHT and TGHT in parallel up to 400+400=800A.

Sunday, July 28th

One leg of the target is glowing a bit, while the other doesn't. This suggests the current path is not straightforward as we planned.

Temperature measurements of the cables on top of the test stand were performed using a mini IR thermometer (FLUKE, borrowed from Arthur).

Temperature of the braided cable from C to H = ~50 °C --> This points to an imbalance of current between the two lines (TGHT and COIL lines). This might be alright.

Temperature of the braided cable from H to I = ~130 °C. This likely points to a short circuit between the target and the copper heat shield.

Monday, July 29th

In order to understand if the target is broken or touching the heat shield, we opened up the service cap.

- The braided cable from H to I was removed

- The braided cable from H to Q was disconnected

These two modifications were made so that the current cannot come back from the heat shield, but has to go through the target lines.

The 4/0 cables from the PS to the feedthroughs were removed so that we could confirm there is a short between C (target) and I(HV ground/heat shield). The 4/0 were than put back on the feedthrough connections.

Under advice of Dan Louie and Arthur, we did not change any configuration of the power supplies. We know that the current would go through the controls loop, but the impedance of this electronics should be high enough to sustain the current load.

At 3pm, the ramping was still increasing the current on the target, but one leg (the right one) was still glowing. By this time, the total current in the target assembly is ~500 amperes, so there should be no signs of any glowing happening. Probably there's something wrong with the target itself. We're opening up to check the status of the target.

Tuesday, July 30, 2019, 10:00: Venting. 

Tuesday, July 30, 2019, 10:03: Purging heat shield water loop. 

Tuesday, July 30, 2019, 11:46: P2N removed

The p2n target was taken out of the test stand for inspection. Comments and measurements on the container below:

- Initially, continuity measurements were mode between the target and heat shield (HS) while they were still in the test stand, and looks like they were shorted. However, after removing the HS from the test stand, no short was seen, not even after moving the target legs. Instead, we confirmed that the short was happening in the test stand, so some water lines were touching each other. 

- The target look in one piece, except for the ion source that came off right after manufacturing. (see picture)

- The insulator connecting the bottom section of the ion source central current lead, to the HS, was broken (see picture)

- The annular disc of the connecting the inner and outer tube of the ion source was bulging outwards, maybe the ion source was heating too much while we put current in it (see picture).

- The screw connecting the top part of the central ion source current lead, is now of a blue-ish color

Resistance measurementts:

- Copper to copper: 1008 microOhm

- Copper to bottom flexy leg: 101 microOhm

-  Bottom-to-top (flexy): 30-45 microOhm

- Target: 476 microOhm

- Copper to top flexy: 261 microOhm

- Copper to bottom flexy (left): 100 microOhm

- Copper to bottom flexy (right): 94 microOhm

- Top Flexy - botton target assy (left): 88 microOhm

From left to right:

- Cu to bottom flexy leg: 102

- Flexy bottom to flexy top: 31

- Flexy top left to flexy top right: 473

- Flexy top to flexy bottom: 0 (???)

- flexy bottom to Cu: 93

Tuesday, August 06, 2019, 16:00

Start ramp up to 300+300 = 600 A

Tuesday, August 06, 2019, 17:30

Wednesday, August 07, 2019, 08:11

The same p2n target was installed in the test stand, taking off the ion source since we thought it could have been shorting to the reference electrode and providing a return path for the current, hence generating the asymmetric heating that was noticed on the target.

On Tuesday 6th afternoon, the p2n was ramped up to 600 A (300 + 300 A from TGHT and TBHT in parallel). The target and its right flexible leg were still glowing. After noticing it, the current was ramped down wating to open up for inspection.

 The electrical feedthroughs at the top of the test stand module were reconfigured to deliver up to 1200A to the p2n target.

1) The two COIL lines (one + and one -) were disconnected from their terminals E and F

2) The TBHT terminals (two + and two -) were disconnected from A and B

3) The two TBHT positive terminals are connected to E and G respectively. The two TBHT negative terminals are both connected to F, and a 4/0 cable is run from F to H

4) The three TGHT + terminals are left connected to D. The three TGHT - terminals are left connected to C

In the vacuum chamber, COIL and TGHT terminals of the same polarity are shorted by means of thick copper bars specifically machined to match the test stand terminals geometry. The test can proceed by ramping both TGHT and TBHT up to 600 A each, possible at the same time and speed.

The wiring diagram is shown in the attached picture 

Extech measurements before heating (µOhm):

TGHT Left leg Ta-Cu: 205, 215, 212, 201.

TGHT Right leg Ta-Cu: 287, 295, 275, 292.

TGHT Ta legs: 596, 606, 597, 598.

TBHT A: 1470, 1471.

TBHT B: 1469, 1469.

Wednesday, July 22, 2020, 16:21

Rampup finished around 2PM, looks good. Around 300+300A the TBHT voltage limit prevented the TBHT current to increase, and instead it decreased. Aaron ramped it down, adjusted the voltage limit and proceeded without issues.

The water flow and temperatures looked fine.

Attached the plots and a picture at 1200A

 Thursday, July 23, 2020, 11:53

Frank Song checked for us the status of the test stand. Pictures looked good, despite the reflections, I can't see sign of the flexy legs glowing. Thank you Frank!

The voltage on the TGHT has dropped 0.02 V, and the voltage on the TBHT (COIL lines) has dropped by 0.04V in 20 hours. I think it's negligible, just a sign of some sintering.

The cooling parameters are as follows:

Input 1: 28.05 C

Input 2: 8.49 lpm

Input 3: 27.79 C

Input 4: 11.14 lpm

Input 5: 27.72 C

Input 6: 3.90 lpm

Input 7: 27.78 C

Input 8: 7.79 lpm

Friday, July 24, 2020, 16:42

This morning I saw the target for my first time and not in a picture. I could see a mild glow in the center of both flexy legs, while the external foils seemed cold. This seems really good, as expected!

Water parameters were checked:

Input 1: 27.75 C

Input 2: 8.38 lpm

Input 3: 27.52 C

Input 4: 11.13 lpm

Input 5: 27.37 C

Input 6: 3.93 lpm

Input 7: 27.53 C

Input 8: 7.78 lpm 

Monday, July 27, 2020, 09:35

Aaron's measurement from today at 7:30am

 Input 1: 26.61 C

Input 2:  8.25 lpm

Input 3: 26.35 C

Input 4: 11.19 lpm

Input 5: 26.21 C

Input 6: 3.84 lpm

Input 7: 26.35 C

Input 8: 7.76 lpm

FM

Thursday, July 30, 2020, 15:53: Auto-cooling TGHT/TBHT to 0 @ 4 A/min 

Thursday, July 30, 2020, 23:02

Ramp down terminated around 7pm, the current was ramped smoothly but the voltage from both PS (TGHT and TBHT) had some bumps in correspondance with vacuum response. Maybe something was shorting? A thorough inspection of the heat shield and target might tell more.

Thanks Fernando for ramping down! 

Tuesday, August 04, 2020, 07:33: PS / sources off. Lock out. IG & Turbo pumps off. Purge waterlines. - AS

Tuesday, August 04, 2020, 09:32

Started rewiring the test stand.

TBHT+ (A1 and A2): connected to A

TBHT- (B1 and B2): connected to B

COIL+ (A3): connected to E

COIL-(B3): connected to F

4/0 short connection from F to H removed

Tuesday, August 04, 2020, 15:27

Extech measurements after heating (µOhm):

TGHT Left leg Ta-Cu: 160, 176, 184, 180

TGHT Right leg Ta-Cu: 49, 48, 52, 53.

TGHT Ta legs: 470, 469, 463, 480.

TBHT A: 2400, 2229,2492.

TBHT B: 2361, 2411, 2412.

 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.

 Wednesday, April 28, 2021, 22:30

First P2N heating test ongoing.

At P2NHT ~ 570 A and TBHT ~ 100 A shine is already seen, which suggests that current is flowing in the P2N target properly, see picture attached.

Most of the ramping is carefully monitored because the good vacuum signal from the TTS ramping procedure is obviously not working (bypassed), and if the pressure goes past 1E-5T the whole ITS should interlock and abruptly drop the currents, which we want to avoid.

Wednesday, April 28, 2021, 23:16

P2NHT set current = 810 A

P2NHT read current = 800 A

Master and slave have balanced fully, TBHT ramping still proceeds manually. I'm trying to get it to ~200A before leaving.

 Thursday, April 29, 2021, 00:54

Ramping successfully achieved.

P2NHT_Master = 594 A - 4.59 V

P2NHT_Slave = 611 A - 4.89 V

P2NHT = 1207 A

TBHT = 231 A - 2.29 V

Max temperature of welding cables = 40 deg

Zero current from the HV ground terminal (feedthrough I) to slave negative (feedthrough H)

Beginning of May:

The cabling on the top of the test stand was changed to adapt for P2N testing. The TGHT and COIL PS were disconnected, and their DC cable terminals were connected instead to the TDK-LAMBDA P2Nheaters. The configuration on top of the ITS module is the following:

TBHT+ = A

TBHT- = B

MASTER+ = D

MASTER- = C

SLAVE+ = G/E

SLAVE- = F/H

Friday May 6th, afternoon

Once the pressure was almost stable in the low E-6 torr range, the first rampup was conducted up to ~600 A and the I,V parameters looked similar to previous P2N units. More tests to full current happening next week.

Monday, May 09, 2022, 09:29

P2N unit is being heated now, the automatic ramping utility is ramping the TDK-LAMBDAs while the TBHT is being increased manually.

Monday, May 09, 2022, 10:31

A voltage event happened, the TBHT voltage increased frmo 0.64 V to 0.73 V, while the P2Nheater dropped from  1.73 V to 1.56 V. 

Monday, May 09, 2022, 12:19

At P2NHT=950A it was noticed that one leg of the P2N was glowing much more than the other, the ramping was first stopped and then ramped down.

Now the P2NHT=282A and TBHT=47A

Tuesday, May 10, 2022, 09:32

Test stand vented and target inspected, there is no obvious sign of damage or misconnection on the tantalum assembly. Some resistance measurements were taken across target elements and connections: 

Screw on copper L to bottom flexy leg L = 117

Bottom flexy leg L to top flexy leg L = 24 / 0 (?)

top flexy leg L to bottom elephant leg L = 64

elephant L to elephant R = 360

top flexy leg R to bottom elephant leg R = 69

Screw on copper R to bottom flexy leg R = 125

Tuesday, May 10, 2022, 11:39

This morning, the target was inspected but nothing major was noticed, hence it was put back in the ITS for heating.

Tuesday, May 10, 2022, 17:40

Target being ramped: so far all good, total current in P2NHT=690A and TBHT=116A

A current measuring clamp was used to measure current in the 4/0 cables. The only bad thing is that the slave outputs half the current than the master, making the cables hotter (30deg vs 24deg).

Currents:

A-B ~116 A (TBHT)

C~468

E~124

G~102

Tuesday, May 10, 2022, 17:45

Event: reduction in P2NHT voltage and increase in TBHT voltage. After letting the PS ramp, it was noticed that the P2NHT voltage accelerated its increased, and the left leg started glowing like the previous time. The current was immediately ramped down, but still there was a voltage spike upwards in the P2NHT. 

While the leg was glowing hot, the current between feedthroughs H (P2NHT-) and I (HV common) was 90A. Now that the "episode" is not there any more, the current is zero

Wednesday, May 11, 2022, 10:55 

The previous P2N target had stainless steel screws at the bottom, where the copper L-shaped connector and the ta foil legs connect, which might have bene the cause of the gap opening and voltage increase. Now, the target manufactured for the previous beamtime is used, which does not have the cuts on the elephant ears but they are OK since don't interfere with the new IS cup design, and are ~3mm away from it.

Wednesday, May 11, 2022, 13:57 

 Start heating the new P2N assembly

Wednesday, May 11, 2022, 14:58

 Stopped at

P2NHT= 501 A

TBHT= 95 A

All currents seem to be flowing in the right path, with no current in the jumper between H-I

Wednesday, May 11, 2022, 15:26

Voltage step in P2NHT and TBHT happened again. Current sum:

A = 125 A

B = 125 A

C= 470 A

D=474 A

E = 118 A

F= 85 A

G = 95 A

H = 132 A

Short G-E = 5 A

Short F-H = 3 A

Jumper H-I = 62 A

The most likely explanation of this jump is that the IS tip touches the plasma electrode as shown in the drawing below which would result in some current flowing through the jumper, more investigations are needed

Thursday, May 12, 2022, 08:19

Test stand opened, there is some sign of burn in the plasma electrode, but it's hard to say if it's because they were touching. Aaron added a tantalum 0.040" shim to the plasma electrode to distance it further from the target IS tube

Thursday, May 12, 2022, 13:20

ITS with P2N target installed and pumping down 

Thursday, May 12, 2022, 15:50

P2NHT started ramping 

ABC 123 blah blah blah...

Wednesday, September 14, 2011, 15:33

blah blah blah...

Anders Mjos wrote:

Friday, September 23, 2011, 16:3: The connection on the 9-pin connector for FEBIAD targets showed burn marks from the previous FEBIAD tests. Corresponding mark was found on the connector on the target side. Because of this the upper and lower 9-pin connectors were swapped to have a clean connector for the next FEBIAD target.

 See attachment#1: 9-pin-connector.jpg 

 Thursday, May 17, 2012, 13:15

After the test-stand, the EE was removed for inspection.  It was discovered that there were some solid residues coated on the extraction electrode and the common plate, but the ionizer tube was clean (see attachment#1).  Some samples were collected and will try to do some analysis.  This problem has been seen before but it's still not clear why the solid residues form after the test-stand.  

The EE & the common plate were cleaned with acetone and re-assembled back to the target.  

Opened the ATTS, placed what I will call “Cast Alumina Sample #1” into the ATTS and activated the roughing then turbo pumps. Currently sample is in slow heating progress to 1000 degrees Celsius, process is expected to take some time, so I'll revisit after lunch.