Hopefully we will not be opening the chamber for quite some time so find attached images of all four installed detectors and a video of them both moving into the beam axis for future reference

Strain reliefs on the flange side of the cable harness have been installed for two detectors (top right and bottom right detectors). 

We require the strain relief parts from edinburgh in order to install strain reliefs for the left two detectors. 

Find attached images for the strain relief installed and a video of the clamped cables during a movement cycle.

A V-I test was performed for the two detectors which have all strain reliefs installed (see attachment 4).  V-I curve appears similar to the previous test (elog 398). Aluminium foil shield is now a bit battered so may have some small light leaks. Detectors were moved using the motors while bias was applied at 150V. Small change in leakage current observed (~0.01-0.02 uA)

The detectors were moved into the beam axis using the motors to check the maximum distance they can be moved in without collision with one another. 

Movement of both pneumatic motors results in a separation of ~ 4 cm between the detectors.

The servo motors for left and right were each moved in by 1 cm -> results in separation of 2 cm between the detectors

The servo motors for left and right were then each moved in by 5 mm -> results in separation of 1 cm between the detectors

The separation between the jacking plate of one of the detectors and the side of the adjacent detectors is closer than the separation of the detector silicons. The detectors could not be moved in any further than this to avoid collisions from the jacking plate

Attached are photos after movement of the detectors. Parallax may affect the distance on the ruler in the photos. 

During beam time -> Maximum distance that can be moved on the servo motors is 30 mm combined for left and right. (15 mm left and right or 10 mm left, 20mm right etc)  

The new MACOR strain reliefs on the (detector side) have been installed. See attached photos

The two pieces  of MACOR are not fully closed but we are confident that the kapton wires are sufficiently clamped.

In order for the strain reliefs to be installed in the correct poisition, two nuts on the jacking plate of the cable harness had to be removed. This is as the groove in the strain relief was not deep enough to accomadate the nut. 

Attached is also a video of the wires (not) moving with the strain reliefs mounted

08.35 DSSSD#3 bias -149.95V leakage current -6.418uA temperature +19.6 deg C ( https://web-docs.gsi.de/~lestinsk/tempplot.php )

DSSSD#3 bias OFF

12.44 DSSSD#3 bias -149.95V leakage current -6.448uA temperature +19.7 deg C ( https://web-docs.gsi.de/~lestinsk/tempplot.php )

CRYRING cave lights ON - leakage current measurements @ 60s intervals

6.448
6.449
6.448
6.448
6.449
6.448
6.448
6.448
6.449
6.448

18.24 DSSSD#3 bias -149.95V leakage current -6.442uA temperature + 21.0 deg C ( https://web-docs.gsi.de/~lestinsk/tempplot.php )

CRYRING cave lights ON - leakage current measurements @ 60s intervals

6.441
6.441
6.441
6.441
6.441
6.442
6.442
6.442
6.440
6.441

12.34 DSSSD#3 bias -149.95V leakage current -6.763uA temperature +21.2 deg C ( https://web-docs.gsi.de/~lestinsk/tempplot.php )

CRYRING cave lights ON - leakage current measurements @ 60s intervals

6.763
6.764
6.764
6.765
6.767
6.767
6.767
6.767
6.768
6.769

12.48 CRYRING cave lights OFF

13.03 leakage current -6.771uA - no obvious change due to the CRYRING cave lighting

17.31 DSSSD#3 bias -149.95V leakage current -6.658uA temperature +21.0 deg C ( https://web-docs.gsi.de/~lestinsk/tempplot.php )

leakage current measurements @ 60s intervals

6.656
6.655
6.655
6.655
6.654
6.652
6.652
6.651
6.650
6.649

CRYRING cave temperature variations/cycles ~0.1 deg C at +21 deg C ambient temperature can produce leakage current variations ~60nA for a leakage current of ~6.6uA

td@winder:~/f77$ ./jgen
 *** Enter reference temperature (K)
294
 *** Enter minimum temperature, maximum temperature
 *** and temperature increment (K)
290 298 0.1

 Temperature (K)   Ratio (J(T)/J(294.0))

      290.0                0.702
      290.1                0.708
      290.2                0.714
      290.3                0.721
      290.4                0.727
      290.5                0.734
      290.6                0.740
      290.7                0.747
      290.8                0.754
      290.9                0.761
      291.0                0.767
      291.1                0.774
      291.2                0.781
      291.3                0.788
      291.4                0.795
      291.5                0.802
      291.6                0.809
      291.7                0.817
      291.8                0.824
      291.9                0.831
      292.0                0.839
      292.1                0.846
      292.2                0.854
      292.3                0.861
      292.4                0.869
      292.5                0.877
      292.6                0.884
      292.7                0.892
      292.8                0.900
      292.9                0.908
      293.0                0.916
      293.1                0.924
      293.2                0.932
      293.3                0.941
      293.4                0.949
      293.5                0.957
      293.6                0.966
      293.7                0.974
      293.8                0.983
      293.9                0.991
      294.0                1.000
      294.1                1.009
      294.2                1.018
      294.3                1.027
      294.4                1.036
      294.5                1.045
      294.6                1.054
      294.7                1.063
      294.8                1.072
      294.9                1.082
      295.0                1.091
      295.1                1.101
      295.2                1.110
      295.3                1.120
      295.4                1.130
      295.5                1.139
      295.6                1.149
      295.7                1.159
      295.8                1.169
      295.9                1.179
      296.0                1.190
      296.1                1.200
      296.2                1.210
      296.3                1.221
      296.4                1.231
      296.5                1.242
      296.6                1.253
      296.7                1.263
      296.8                1.274
      296.9                1.285
      297.0                1.296
      297.1                1.308
      297.2                1.319
      297.3                1.330
      297.4                1.342
      297.5                1.353
      297.6                1.365
      297.7                1.376
      297.8                1.388
      297.9                1.400

STOP *** Program ends

Since yesterday evening, the bottom right detector was at -150 V. In the morning, the current was quite stable ~ 6.77 uA. The bias was switched off, the foils opened, both of the detector arms were moved in and out three times, and the chamber was tightly covered again. A negative bias voltage was applied from 0 to 150 V in steps of 10 V one by one to all four detectors, and the V-I results can be seen in Attachments 1-4. All detectors seem to be fine. The variation of the current with time at a constant bias voltage of -150 V was checked for all detectors and the results are in Attachments 5-8. Also, with an applied bias voltage of -150 V to the bottom right and left detector, the detector arms were moved in and out three times which showed a variation of 1-2 nA and 1 nA in the leakage current. For further conditioning of the bottom right detector, it is again left with a negative bias voltage of 150 V over the weekend.

Today, the foil was opened, the pins on the bottom right detector were checked and looked fine, the right-hand arm was moved a bit in and then out, and the foil was tightly closed again. The negative bias voltage was applied from 0 to 50 V in steps of 10 V. During the measurement, the lights in the cave were switched off to ensure no leakage current from the light*. The results are shown in Attachment 1. To condition the detector, it was left at a negative bias voltage of 50 V for ~ 3 hours with lights on. No increase in current was seen (see Attachment 2), indicating the chamber was nicely covered with foil. Then the negative voltage was increased from 60 V to 150 V in steps of 10 V. No large current readings, like yesterday, were seen today (see Attachment 3). The detector was then left at -150 V for ~ 30 minutes with the current to be nearly stable with fluctuations in the range of 70-100 nA. The foil was then taken off to check if there are any dust particles on the detector surface. As can be seen in Attachment 6, some dust particle was found at the bias/multi-guard ring (MGR) boundary structures of the DSSSD. The area was then nicely cleaned with isopropanol + lab tissue wipe (see Attachment 7) and the chamber was covered with aluminum foil again. The negative bias voltage was applied from 0 to 150 V in steps of 10 V again and the results can be seen in attachment 5, indicating the response of the detector to be normal, unlike yesterday. Before calling the day off, the detector was left at -150 V overnight.

* Every time, before switching off the lights, it was checked that no one else was in the cave.

To test the detectors, adaptors were installed on the feed through flanges. A negative bias voltage was applied in steps of 10 V from 0 to 150 V. The V-I plots are attached for the four detectors. Three detectors - top right, top left, and bottom left (in the direction of the beam) - are fine. For the bottom right detector (in the direction of the beam), the current was fluctuating and was considerably high (1st test). The adaptors connecting to this detector were removed and checked by applying the bias voltage which showed zero current for voltages ranging from 0 to - 150 V, confirming the adaptors to be fine. They were then exchanged by other adaptors and the V-I test was repeated again (2nd test) with fluctuating and high current values. One of the flanges connecting to this detector was found to be light-tight. These tests were done at an ambient temperature of 21 degrees. Also, we couldn't find the rest of the three SHV to 2x Lemo 00 cables for the detector HV.

Completed mounting harnesses and detectors.

The strain relief support for the bottom most two detectors on the feedthrough side was not mounted because we could not find enough MACOR parts and mounting flanges. We cannot find them in GSI, possibly they are somewhere not obvious in Edinburgh.

The strain relief on the detectors' side are still being manufactured.

We plan to test the detectors electrically from next week without moving the dolly. DR and OG to find a temporary mounting point for the manifold so that FEEs can be cooled in current configuration.

Mounted four detectors on Carme ad well as four cable harnesses.

Cables for new, shorter harnesses appear still too long. Likely the model is not correct somehow.

One feedthrough flange was found to be damaged by an adaptor card. Tried to fix in vain. One pin is missing. Replaced with another.

(31 April)

Remounted 3335-12 on top and new 3335-1 on bottom of left hand plate. Used new dog legs and old standoffs.

Dismounted all harnesses and feedthroughs from CARME. Dismounted all blind flanges on right hand side. Also had to dismount bottom SAES feedthrough due to a bolt falling inside.

Remounted feedthough. Remounted left hand detector plate.

Prepared new 3335-11 and 3335-13 on top and bottom of right hand plate. Planning to mount tomorrow.

Also planning to start jacking in detectors to new harnesses.

Not possible to test any detector on the bench due to lack of appropriate multimeter probe. Will have to test with harnesses.

(29 April)

Inspected CARME after opening. See attached. Some key takeaways.

- No visible damage to the detectors or the Kapton cables. No visible deposits or dust on the detectors either. 

- No damage even to the fragile thermocouple wires

- The strain relief on the top and bottom did nothing. Those on the sides may have helped.

- The split funnels on top fell and fortunately missed the detectors. We should not keep them. Unclear if they feel when moving CARME or during the beamtime but either is too dangerous. We need another solution or we'll have to do without.

- Obvious traces of white dust particles over the chamber. Most likely MACOR.

Jacked out harness for bottom left detector that was not accepting bias. MACOR shavings fell off while jacking out. MACOR connector on side with no pins is clearly damaged. See attached. Should not affect performance.

Tested bias pins - they work. No visible damage to the detector except one bias bond wire has disconnected. Possibly one more nearby. TD thinks this is not enough to explain observed behaviour.

Mounting a DSSD on the plate while it hangs in Carme appears possible but very risky. Dismounted whole left support plate, and right support plate. 

Unless a clear fault can be identified for either the bottom left detector or its harnesses, both the detector and the harnesses will be replaced. Plan to remount top left detector with the same harnesses.

Plan to mount two more detectors on the right hand plate.

(28 April)

Mounted rails on dolly. The rails don't smoothly connect to those on the Aluminium frame and some thin metal shims were required to get the correct height. A metal support had to be placed above the Delrin pads to support the rails above the gap between frames.

All side feet were mounted but extensive modifications were required to slotted feet due to them not being manufactured to drawing, and to Carme middle section flange width being incorrect (see previous entry).

Removed brakes and started sliding CARME out. The dolly and the aluminium frame came partly separated as the weight of the side feet was shifted on the latter. Strapped them together. No damage.

Kept sliding. Sliding when the carriages passed from one rail to the other was quite hard. The back carriage on the left looking downstream lost a single ball bearing when crossing over. A more sophisticated solution is probably required.

Once Carme was on the dolly, opened it using M8 jacking bolts and lifted away front and middle section. 

No obvious damage inside but strain relief did not work as intended. Photos to be uploaded after more detailed inspection on Saturday.

Plan to install right hand side detectors over the weekend. Unclear if bottom left detector is damaged and needs to be replaced.

Removed turbo pump and set aside in a box. Considering switching to the other turbo to avoid degradation due to lack of use.

Installed bellows support and OG devised support to avoid bellows sagging when Carme is split open.

Attempted to install new CARME feet, but there were issues. Feet with slots produced do not match design drawings by PB. Slot is in the wrong side. Furthermore Carme interaction chamber flange thickness is 36 mm vs. 36.5 mm in drawing. DR can modify feet to make them fit tomorrow.

Now just waiting for rails to open CARME. Will arrive tomorrow or on Tuesday, after weekend and Mayday.

Disconnected cables from CARME motors and turbo. The turbo has to go to allow Carme to slide out. Crane may be required to lift because it's in a very hard spot to access.

Dolly mostly built. See attached. Left side doesn't quite fit right by 1-2 mm. Might be okay anyway but will put some shims to avoid any shaking during sliding.

Waiting for the rails to arrive due to GSI procurement issues.

Plan to mount new feet and bellow support tomorrow.

Also plan to split CARME at the smaller flange towards the interaction chamber, after the bellows and before the bellows towards the magnet on the downstream side.

CARME venting using nitrogen gas bottle. 

Coolant pipes dismounted from the chamber

Feed-through flange for n+n bias flange for bottom detector has a bent pin image attached. Clearer image of bent pin for ERNI connector used for aida03 also attached. All other feed-throughs and adaptor cards appear undamaged. 

CARME currently in vacuum, pressure ~3E-10 mbar. Chamber to be vented tomorrow afternoon by vacuum division. We have active both pirani and hot cathode gauge to aid. 

Equipment removed from the chamber in preparation for dismount of CARME from the ring this week. Equipment removed includes:

• Neg pump cabling
• Heating wire
• FEE electronic units and associated cabling (power, hdmi etc)
• Stainless steel FEE holders
• Red and blue cooling hoses

Attached image shows chamber following equipment removal. Adaptor cards still attached to feed-through flanges. ERNI connnectors examined, all fine except for FEE aida03 which has a bent pin (see attached image). Will dismount adaptor cards to examine further tomorrow. Feed-through flanges will also be examined to check for bent pins following adaptor card removal. 

New CARME frame is part constructed and is in the CRYRING area. Requires rails and castors which should arrive this week. The height of the frame will require shortening, to be level with the current frame. This will be looked into further tomorrow. 

Test of NIM WR source at Edinburgh

Attachment 1 - NIM WR source

NIM module upper SMA - DSO ch 1
NIM module lower SMA - DSO ch 2

Attachment 2

NO SYNC or CLK signals observed.

Noise observed with NIM bin power ON *and* OFF

Attachment 3

NIM WR source in EG&G Ortec NIM bin



... and with the Digilent Zybo board switched ON!


Attacments 4-7
Trigger ch 2
4, 40, 400 & 4000ns/div

Attachment 8
Trigger ch 1
4ns/div