(Tue 26 October)

Two new CARME DSSD arrived in GSI and collected. Visually inspected both sides. No obvious damage. Photos attached. Second detector (3335-2) was shipped in upside-down box. Does not seem to have made any difference.

3335-13 will be mounted on bottom of plate. 3335-2 will be mounted on top of plate.

(Mon 25 October - Tue 26 October)

Considered different strategies to mount DSSDs inside CARME, while waiting for 2x new DSSD to arrive.

Plan A: Mount DSSDs on plate on the bench, slide plate on rod, then attach cables, then attach strain relief

Plan B: Mount DSSDs on plate, attach cables, attach strain relief, slide plate on rod, connect cables to feedthroughs

Mounted detectors on plate using new "dog leg" connectors. Threaded and unthreaded holes are flipped! Asked DR to unthread hole in two out of four, and clean.

Attempted to proceed with Plan B with stand-in broken detector. Found even a single wire harness attached to the detector was quite hard to insert in the chamber. Temporarily dismounted left-hand 2x UHV1400 to give more space.

Slid plate on rod. New position of rod block makes it easier to mount. Spraying ethanol on the rod to lubricate also helps greatly. Secured plate to rod. Holding flange with cables in left hand, attempted to mount macor plug in feedthrough with right hand. Unable to exert sufficient strength (CB, JM, OG). Pulling on the cable puts strain on the DSSD. Decided to avoid.

Attempted Plan A. Jacked connector in with no issues using M6x40 partly threaded bolts. Unable to unjack due to part threads! Obtained fully threaded rods. Unjacked using washer + two nuts tightened on each other. Jacked and unjacked another connector.

Decided to proceed with A. Having any cable pre-mounted in the chamber is a potential hazard to the detectors while mounting plate. Decided to dismount all flanges, re-organise harnesses and mount one flange+harness at a time after mounting detector on rod.

Used thick Kapton coated Cu from NEG pumps to organise the cables and improve strain relief.

Due to width of MACOR strain relief and nuts on the back of the MACOR plugs, realised strain relief cannot be mounted as intended. Asked DR to produce 90 x 30 x 3 mm extender plates instead. MACOR strain relief are 15 mm wide. Extender plate have 3x M4 unthreaded countersunk to fix to detector plate, 3x M4 threaded holes to hold MACOR strain relief.

Organised cable harnesses.

4 short: all good -> two to be mounted

2 long: all good -> to be mounted

1 long: Broken MACOR backplate and lead. Lead removed. Attempted to mount with backplate in new lead - unable to do so. Removing backplate requires re-crimping. Will have to send back to Edinburgh

1 long: Wires cross in odd way. Will have to re-organise. Probably requires re-crimping. One pin smashed during jacking. Not sure if rescuable. See attached.

Attachment 1 shows the pump-down of the CARME chamber at GSI before installation of kapton cabling inside the chamber and mounting of the chamber on the ring. Discontinuity in the plot is from switching between the pirani gauge and IE514 gauge. The pumping of the chamber in the turbo regime follows the power law where P ~ 1/(nt) due to outgassing from the chamber being dominated by water outgassing which has an n ~1 dependence (for first order desorption). This is seen in the pumping of the chamber in the turbo regime (Attachment 2) where pressure falls with an n of 1.03. In red the power law is extended to 10^5 minutes, demonstrating the limitations of pumping the chamber without baking. 

Attachment 3 shows the pumpdown pressure and baking temperature (chamber average) of the chamber once mounted on the ring, with all kapton installed in the chamber. Temperature data was lost in the middle of the plot due to the power cut to CRYRING causing temperature data to not be saved to the pi. Some of this data was plotted in elog 87 before beong lost from the pi. Points on the graph correspond to:

Point 1 - Baking started 2pm 23/9/21

Point 2 - Temperature limited to 40C due to high thermal gradients from uneven baking of the volume. Baking stopped 7am 24/9/21 so that heating elements could be repositioned. Baking restarted 10am.

Point 3 - Baking limited to 90C due to tent construction. Negative gradient detected due limitation causing baking to stop around 5pm 25/9/21. Manual mode to 60C. Full power mode restarted 10pm

Point 4 - Temperature of the volume reached 100C. 11am 27/9/21 baking stopped to install new turbo sections. Baking restarted at 3:25 pm Temperature peaks at 130C next morning.

Point 5 - 29/9/21 10am Unexpected power cut at CRYRING, temperature fell to 120C power restored shortly after.

Point 6 - 4/10/21 9am Temperature reduced to 100C and ion pumps outgassed. Activation of NEG pumps

Point 7/8 - Subsequent activation of other NEG pumps.

Point 9 - 7/10/21 CARME reached 9E-12 mbar. Gate valve closed, pressure rises with apparent floor at 1.5E-11 mbar

Some variations in the pressure are seen after reaching the floor, most likely due to sputtering of ion pumps. 

Teething problems with the bakeout such as heater placement and new jacket sections in addition to the power cut prevented continous bakeout for entire period, these issues should not affect the next baking run. As a result of the slightly fractured bakeout the pumpdown power laws have been plotted (logP) against log(T) in sections where temperature was roughly constant with the associated timestamps to gauge the decrease in pressure over time using this power law (Attachment 4). 

Room temp  n ~ 0.75

90C n ~ 9.15

130C (1) n ~ 8.05

130C (2) n ~ 7.37

130C (3) n ~ 4.89

130C (4) n ~ 2.65

Introduction of kapton cabling likely causes change to scaling as the diffusion of gas from kapton not the desorption from the surface dominates the outgassing rate. Diffusion has an n ~ 0.5, likely contributing to the change between the blank chamber and mounted chamber. As the temperature is increased the outgassing is significantly increased causing an initial increase in the temperature followed by a more rapid decrease in the gradient of the pressure decrease over time than at lower temperatures. As time increases, outgassing from water in the chamber dominates less and less with the kapton cabling representing a more significant portion of the total outgassing load likely causing the decrease in n as time increases despite baking at 130C. After ~12000 minutes n decreases significantly and more variations from the linear decrease in pressure are observed. After 17000 seconds the pressure begins to plateu and reached a floor of ~1E-7 mbar over the weekend at which it was assumed outgassing from water in the chamber was no longer significant. Variations could be due to temperature fluctuations which had a greater impact on the pressure as the pressure began to reach the floor.

Activation of NEG pumps was conducted after reaching the floor. The average chamber temperature and air temperature inside the tent was unaffected by the activation of NEG pumps, however the internal thermocouples significantly increased during activation (attachment 5). The internal thermocuples were largely unaffected by the NEG activation until the NEG temperatures were themselves above ~300C after the internal temperatures rose rapidly (more detail in elog 105,108,109,110) . Activating so many NEG elements at once is thus not feasible as temperatures would damage the detectors once mounted. Activating one group at a time (typically 2 NEGs) and D2000's which are away from the detectors to start with and then maintaining at low power before slowly activating NEG's close to the detectors perhaps at a lower temperature will be done to keep temperatures below 130C. A full activation procedure will be posted to the elog before activating again.  

NEG pump electrical connections tested - all connections sound. 

Detector carriers have been redrilled and are currently being cleaned. Carriers were checked within the chamber, mounting much easier with new hole. Distances to NEG feedthroughs and thermocouple feedthrough from the carrier also checked. NEG feedthroughs have sufficient separation now moved, thermocouple required moving to top flange position to avoid collision with carrier. 

Longer external thermocouples required for top position to reach TC08's. 3 Longer thermocouples made up using spare wire and connected to feedthrough. All thermocouples checked using baking code - all appear fine. We have 2 long thermocouples for the interaction chamber, 2 for the RE-72's and one for the top of the chamber left. Bellows can be reached by shorter thermocouple. This should be sufficient for baking. 

Standoffs job submitted to workshop for production, may be available end of the week depending on schedules of workshop. Clamp guide and hook tools produced.

Cable connectors have started to be seperated and bound into 16 and 17 cable bunches to enable a good fit in strain reliefs. Upon inspection D-connectors were attached upside down and required flipping to correct position (see image - thumbs up indicates correct position). Cables fit through funnel strain reliefs well, other strain reliefs look more difficult - may require more hands to complete. One long connector has criss crossed wires which may not fit in strain reliefs and may require re-wiring a few cables and one long has broken D-connector. Broken ceramic can be replaced with new D-connector and other long connectors are available

Damaged detector removed from carrier and is in its box - awaiting delivery of other detectors. 

Interaction chamber mounted on its frame in CRYRING as well

Kapton cabling and the broken ceramic detector holder have been separated. Required holding jacking plate in a vice and using lots of propanol to wet the jacking screw. A long set of kapton cabling has been removed from the other side of the chamber which can be used when mounting the detectors. The feedthrough flange was re-mounted on that side with no kapton cabling. 

The wiring for the NEG feedthroughs was in confilct with detectors in previous position. Feedthroughs have been moved to the DN40 flanges at the top and bottom of the chamber section. In order to wire the NEGs to the feedthroughs required rotating the NEGs one position anti-clockwise and re-wiring some of the connections. 

Left two Getters are connected in series and are connected to the top feedthrough. The two right and the bottom getter are connected in series and are connected to the bottom feedthrough

Looking downstream the RHS motor assembly has  loose green/yellow (gnd?) see attachment 1

Install blank base plate to trial install in downstream CARME chamber. The rod is just through all of the mounting holes - see attachments 2 & 3

The rod, plate and block are close fitting.

The current position of the TC feedthrough is incompatible wit detector movement- the TC feedthrough should be moved.

Detector baseplate with 1x DSSSD installed - attachments 4 - 6, Cabling length looks OK. 

Should move NEG power and TCs to top & bottom DN40 flanges to avoid conflicts with DSSSDs and cabling.

One of the detectors was damaged while mounting (see pictures 1-3).

Second detector was found already damaged when opened (see pictures 4-5).

Ring seal is out. See picture 1.

Bellow (towards CARME) was installed in the gas jet chamber. Attached are some pictures.

Attachment 1 - what is function of the 4x c/s holes indicated?


DSSSD install sequence

1 add 136 - 2x78 way cable harnesses to DSSSD mount via strain relief

2 add DSSSD to mount

3 connect 136 D connector

4 install in CARME chamber 

5 connect 2x78 D connectors and strain relief to 2x78 way D connector 
feedthroughs 

Attachment 2- pins of one of the four feedthroughs were damaged. Needs to be replaced.

Split funnels installed on 4 (of 8) 2x78 way D connector feed-throughs.

Looking downstream

Attachment 1 top right pair
           2 bottom right pair
           3 bottom left pair
           4 top left pair

PB "The long sides of the connectors on the 2 lowest flanges should be next to each other
and the short side of the connectors should be towards the motors."

The orientations of the other flanges do not matter.

'Long' cables to L-R connectors, 'short' cables to U-D connectors.

RSS & TD had some success cleaning the COF600 flange surfaces of the staining and residues observed when the downstream COF600 section was opened yesterday  
https://elog.ph.ed.ac.uk/CARME/118

Isopropanol and laboratory tissues were used - most but not all of the staining and the residues were removed.

Use the M10 jacking points provided top/bottom and 
left/right on the upstream and downstream sides of the 
flanges - for example see attachments 1 & 2

With the assistance of Oemer and Davide all of the M22 bolts removed from the downstream section of the CARME chamber. To separate the downstream section from the 
upstream sections it was necessary to use a lever between M10 bolts screwed into the lift points of adjacent sections of the CARME. The upstream sections were then 
lifted from the support frame and placed on the shipment crate base. The open ports of the CARME chamber sections were covered by Al foil.

Attachments 1-3 show downstream section following removal of upstream sections of CARME chamber. Note staining/residue top and bottom right - attachments 2 & 3.

Neg and ion cables were taken off and were put in the box.

Top support was taken off.

Motors are rotating again. Have to be careful with the position of the limit switches.

Split funnels were given to Oemer for cleaning. Have received them back after lunch.

Valve support is installed again (see picture 1).

Ion pump was connected but not activated. Michael will help in doing so. No vacuum support to help will RGA. Will proceed without it.

Neg and ion cables were labeled (see pictures 2 and 3).

Chamber was vented using nitrogen.

0. Give split-funnels to OG or Grossmontage to clean. Mount back foot support for gate valves. Critical when we split.

1. Wait for vacuum division to come to install: IE514 cables to current CM52 module, ion pump cables + controls + turn on, RGA head + program + turn on

2. Vacuum division should also bring N2 gas to vent CARME. Ideally vent by Wed to avoid losing time. Remember to disable ion pumps and remove all cables when venting.

3. While waiting to vent, connect pneumatic hoses to motors box in CARME rack. There is one pneumatic in (central feedthrough) and four pneumatic out. See picture attached. Top two go to left pneumatic motor, bottom two go to right pneumatic motor. Of each set of two, one is for extending the motor and one is for retracting but unclear which is which. Try to connect and operate motor manually by pressing on buttons on top of pressure reducer to ensure everything works. Don't forget to remove the safety pin.

4. Some disassembly of the servo motors may be required to get them operational. Use the Windows ClearView program provided by Teknic to control servos and change the function of the limit switches. Download from https://teknic.com/downloads/ -> ClearPath -> Software -> ClearView Install.zip . There is a Linux version but I have never tested it. The code on the raspberry Pi cannot reproduce some of the functions in the official program due to library limitations (but can do other things the official program cannot do).

5. After venting CARME, split open at the COF600 flange close to the magnet. Open CARME by 1-2 cm, remove spherical washers from top of rail studs, and lift with crane. Make sure knife edges of the two halves do not touch. CARME currently has feet mounted and cannot easily be placed on a standard pallet. Either dismount the feet (not easy to remount), or find a pallet on which CARME can land on its belly only, or place CARME on pallet with feet and screw feet down? Discuss strategy with DR asap.

6. Install split-funnels on flanges/wire harnesses in use (no point installing on other flanges). This may require dismounting top flanges. Probably switch from 3 hole to 4 hole configuration with funnels.

7. Test detector support going to actuator rod without detector. Make sure you have all the parts, including bolt to secure support to rod. You may want to push the rod in via pneumatic motor (or by hand pushing the plate outside) to gain better access.

8. Take detector support on table, install *two* detectors on same support, and mount on actuator rod in XHV. Connect wires and close via jacking plates. Optionally, consider mouting empty support on other rod? May be useful for diagnostic/scraping?

9. Move XHV thermocouple feedthrough to top flange and connect one thermocouple per detector, one to the support, and leave one floating inside

10. If the motors are fully operational, check how far/close they can be actuated from chamber wall. If not, take some dimensions for future reference.

11. Lift CARME back in place. Close using Pfeiffer COF600 seal and ~72 Nm force per bolt. 80 Nm were required in DL. Probably get Grossmontage to do this. Use our long torque-wrench.

12. Connect to interaction chamber via bellows. Beware gaskets on one side are non standard. One appropriate gasket should be on top of bellows box.

13. Reconnect pumps, rebuild octagon, reconnect thermocouples, rebuild baking tent, bake. Make sure to label the NEG cables this time!

14. Activate NEG pumps following this recipe. ALWAYS monitor temperature and be ready to stop if detector temperature reaches 120 C. NEG temperature does not drop immediately, don't wait until it is too late.

If temperature is increasing too quickly (check rates/h), decrease activation power in increments of 25 W. Remember to flash ion pumps.

A. Start from D2000. Activate one at a time with T 400 C, t rise 30 min, t hold 90 min. Activating a second D2000 while the first has reached its hold state seems safe. Leave at 250 C to keep clean.

B. Continue with UVH1400 furthest from the detector (DSSD wall chamber). Activate at P 200 W, t rise 30 min, to hold 90 min. Finish one set of two before moving to the second. Leave at 50 W to keep clean.

C. Continue with UHV1400 in intermediate chamber. Activate at P 150 W, rest as above. Leave at 50 W to keep clean.

D. Continue with 2xUHV1400 closest to detectors. Activate at P 70 W, rest as above. Leave at 50 W to keep clean.

E. Finish with 3xUHV1400 closest to detectors. Activate at P 90 W, rest as above. Turn all NEGs off when activation of 3x is complete.

F. Let chamber cool. Activate ion pumps at room temperature. Section off turbo pump.

Removed thermocouples, heaters, RE72 modules and leftover baking tent. Support octagon removed except topmost part which requires disconnecting pneumatic hoses going to top gate valve. To be done on Monday with ML assistance.

Attempted to move servo motors once more - did not work. The motors appear stuck but it is not clear how or where. Removed screws on flanged ball nut and on motor back. Still stuck. Moving by hand is not possible. Code likely complains about excessive force on motor startup. Will discuss with PB. Some dismounting once back in air may be required.