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Andrea mentioned to Markus on the phone: reference Grid monitors only the source height. No cooling and no precise position except the height is necessary.
Setup will be extended soon according to these requirements. The Design is ready
Reflectors for fiber coupling:
Reflective coating inside increases amount of light from fibers into the crystals by a factor of two.
With reflective coating, the expected efficiency for the worst case scenario (most backward region) is in the order of 0.5%.
Bochum will send soon the latest light pulser system to Giessen. The deposited energy equivalent of its pulses through the Reflectors need to be specified.
Andrey: Valeri will check if there is enough space to loop the fibers in order to avoid the worst case scenario.
Present form factor wont fit into the bottom of the support beam at the most forward direction due to its tapered shape.
The in summer available Flex-PCBs will be to short for an elevated board position.
Andrey asked Markus to send all present dimensions of electronics including Flex-PCBs to Valeri.
Giessen considers a redesign of the boards. This will take some time and the routing of all Flex-PCBs have to be known in advance.
Changing the barrel design into independent sectors for a better maintenance demands, among other things, an increased cryostat.
Presently Andrey is in contact with Novosibirsk. It is expected, that the necessary cryostat budget will increase by a factor of two.
Malte mentioned, Giessen should have received some new APDs for irradiation. This is not the case so far.
Assembly tool:
Due to the limited maximum crane height, it was decided to lower both tables down. The XY Table is now revised and ready. The slice Assembly table is right now in the workshop
Giessen has produced dummy cables with similar diameter of the designated BADE signal cables to test the size of the available window in the support beam. The Test will be done soon
Peter Wieczorek announced vie email, there might be news about ASIC tests, board developments, Samtec ect. on the next on-line meeting in two weeks.
Bochum needs to know the positions of the temp. sensor adapter boards. Their positions are not yet fixed.
PSL raw data is in Bochum available.
Development of automated validation software is almost finished.
In most cases of the very few APDs which did not pass the automated validation process, it seems, that the measurement process itself has some issues.
Due to the availability of the raw data (before irradiation) and the lack of time, it should be considered to start irradiation of all APDs right now, even without finished data evaluation. If necessary, the corresponding APDs can be sort out after irradiation.
Gießen reminds again the risk of a possible shut down of the radiation facility.
ASICS-FlexPCBs
Presently the devices are in the US for assembly.
Then they have to be equipped with missing capacitors and connectors in Giessen and finally tested at GSI.
It is expected, that all ASICS are ready for mounting around September.
It is expected, that all necessary APFEL-ASICS-FlexPCB-units will be delivered end of September.
After delivery 6 further weeks are needed for tests and final assemblies.
APFEL-ASICs
It is not trivial to find perfect baseline working levels for differential driver. Fortunately, all ASCIS should behave very similar. Only minor adjustments have to be performed.
Input stage is optimized for APFEL-ASIC signals.
Currently a Master Student characterizes the H.D.-ASIC
ADC stage is already tested.
In 3-4 weeks the chip could be able to read out crystals
Assembly of super modules and first slice is expected this year.
So far there is no insulation between super modules and support beam available.
After the (test-)assembly, the support beam can be dismounted for an upgrade with insulation material.
Announced delivery in week 40
GSI have now support from Mainz
First characterizing results promising
Test of analog memory will begin this week
Foreseen sampling freq. 100 MHz
Present test setup has very limited readout speed
Timescale: if everything works fine, there could be a full scale prototype end of next yeary
Pavel waiting for ADCs
Prototypes have to be tested before assembling batches
VIP panels for the front insulation have been delivered today
Now the price for each is much cheaper than during the order for the end-cap, therefore one can consider to use these VIPs for the sidewalls of a slice test-setup.
108 Grids are now in Giessen
29 of the 108 are PSL validated and have clearance for irradiation.
In case of a delayed crystal production a barrel version with some empty slices (without any modules) is preferable. All other solutions will lead to serious problems.
Advantages and disadvantages should be discussed in a dedicated SADC/Hit-Detection-ASIC meeting.
All parts of the modules and super modules official accepted by Giessen.
All temporarily imported barrel tools still sitting in Giessen. They are needed in Russia for the mass production of the accepted parts. There are ongoing bureaucracy issues between FAIR, IHEP and all involved customs. No furter barrel modules between -3 and +3 have been seend to Giessen so far.
The support-beam is now mounted on the first slice. It was figured out, that the design could be improved.
The behavior and therefore possible routing schemes of the FlexPCBs were completely unknown during its design process. Therefore, the positions of the feed troughs for the FlexPCBs are not optimal. Many FlexPCB do not go perpendicular from the super modules into the support-beam. This could cause problems with the thermal insulation, the needed airtightness and the necessary length of the FlexPCBs.
Furthermore, the mounting of the back-planes inside the support-beam seems to be complicated, even with longer FlexPCBs and against the background that the available space is very limited.
One idea was to reduce the thick bottom of the aluminium support beam down to a framework consisting only of some (thick) bars for the thermal insulation feeds. The rest of the bottom could be filled with thin plastic mounting rails or plates. This will create more space for the electronics inside, makes the FlexPCB routing much easier and has for the thermal insulation the advantage, that there is less material with good conductivity. Thorsten tries to make a rough draft of this idea.
Nevertheless, it was decided to try to install the insulation and connect as much as possible detectors with the present design and decide afterwards how the support-beam should be improved.
The needed FlexPCB length for the present support-beam design should be determined.
The support-beam have to be removed within the next couple of weeks for installing the cooling-pipes and insulation as far as possible.
There is a proposal to make the inner-side of the barrel air tight by using a large and thin cylinder.
The bureaucracy issues between FAIR, IHEP and all involved customs have been solved. The boxes with tools ect. arrived at IHEP.
In order to optimize the routing of the FlexPCBs , a test segment of the support-beam have been build in Gießen. It sits above super-module 3 and will be mounted soon.
It is foreseen, that the IHEP colleagues will visit Giessen at least in 2019 to teach the mechanic shop all necessary steps for the complete slice assembly
All drawings have to be fixed for this date and sufficient Crystals with APDs have to be ready
In 2018 another visit from IHEP to Giessen has to be scheduled for several reasons.
APDs will be handled in packages of 30 pieces.
A throughput of 250/APDs per week are intended
Six ASIC-PCBS with LEDs assembled in Mainz
Annealing-test-setup for crystals @ -25°C needs to be defined.
The following has to be checked in advance: Noise with LED pin open and pin grounded. The line could be a nice antenna
There is a proposal to use the fixture for the backplanes to seal the openings in the support beam bottom. Each Backplane package will get an adapter with an rubber washer. This concept has to be tested.
A water cut thermal insulation layer between the super-modules and the support-beam is ready. Their openings for the FlexPCBs have to be manually insulated after its installation.
There are concerns due to the reduced space around the target pipe. It is unclear how much space will be left for all the necessary cables coming from the downstream part of the corresponding two slices.
The necessary bending radius for the inner u-shaped cooling pipe on top of all super-modules within one slice seems to small to realize. An alternative solution might be needed here.
The dry gas flushing concept has still to be developed. So far, it is foreseen that the inlet will be in front and the outlet behind the crystals.
In general, a digital filter, implemented in the SADCs, seems to produce very promising results.
250 APDs have been processed in Gießen according to the new procedure for the forward endcap. Conductive foam was used during irradiation and annealing (48h).
A first multipurpose PCB is now available and will replace in the longterm the conductive foam and the transport boxes.
A first version of the design of the Backplane adapters are ready. Gießen currently produces an overpressure test setup.
For the light pulser monitoring system of the most backward crystals, small prism are again considered. All other cheaper concepts delivered no promising efficiency in “getting the light around the corner”.
A revised Chip will be available end of this year.
Proposal for Backplane mounting inside the sup.beam: use on bar perpendicular to the beam instead of individual Backplane adapters. Could result better sealing of support-beam openings. The design would need a couple of hours manpower.
A team from IHEP will visit Gießen in mid of February to test and modify a new support beam design. They bring soft mock up plates for first tests and further modifications if necessary. After this Gießen will produce stiff segments of the support beam bottom according to the outcome of the visit. With those, a full assembly including backplanes will be tested once more.
During the IHEP visit, the bending of the slice will be measured in the xy-turning table as well. As preparation, the mounting of the technological beam will be tested in advance by Gießen.
Tests are promising so far. All functions seems to work except the DAC. The following solutions have been discussed
use dig-converter external → not enough space on backplane
create luck up tables for each DAC → very resource intensive
new iteration of DAC → prototypes could be available in August
switch to current DAC instead of one which regulates Voltages
Option 3 was in favor of everybody in the end
Fitting of pipes with larger diameter will be evaluated. The cooling liquid flow could be not sufficient with the present diameter
Giessen got an nice offer from the company Hexagon to measure the slice deformation during rotation. The IHEP Group likes to join the measurements. Therefore, it is being tried to settle the 18. February or the 15. February for those measurements.
There will be an installation workshop at GSI in two weeks. There is in principal nothing new to show from the barrel side. Nevertheless one should clearly communicate again our point of view, that a barrel upgrade will be a very complicated and dangerous task.
For the barrel assembly inside the experimental hall one day per slice will be needed minimum. It is unknown or not predictable how time consuming all the cables and houses would be.
Measurements showing that any sealing material, like rubber or foam, won't be good enough to close the openings in the support beam for the FlexPCBs with the current backplane-adapter design against the inner overpressure of each slice. An alternative solution could be glue. Loctite (Henkel) offers a silicon based glue, formulated for nuclear plants. It has to be tested, if the adhesive force could destroy the FlexPCBs during dismounting for example. Nevertheless, it has to be discussed which criteria could lead to such a need later on. The risk of destroying other detector components, independent of using glue or sealing material, is very high. This topic should be discussed during the upcoming assembly workshop at GSI.
Giessen like to get at least 9 matched pairs from the current screening procedure from Bochum to assembly another prototype for several tests. 25 pairs would be the ideal case. Realistic time frame for delivery might be 1-3 weeks.
Concerning the transportation of all remaining APDs from PSL to Gießen, Andrea wants to get in contact with Markus end of this week.
The Samtec delivery of signal cables with an ultra low cross-section arrived at Giessen
The announced delivery time of 45 ordered SADCs in Nov. '18 amounts 17 weeks.
I | Attachment | Action | Size | Date | Who | Comment |
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2.jpg | manage | 238.2 K | 27 Jun 2016 - 13:00 | HansGeorgZaunick | CAD Drawing of mounting plate with potential drill holes for PCB mounting, Nr.1 |
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Holes_for_electronic_plates.jpg | manage | 452.9 K | 27 Jun 2016 - 13:01 | HansGeorgZaunick | CAD Drawing of mounting plate with potential drill holes for PCB mounting, Nr.2 |
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SP50916032113140.pdf | manage | 409.3 K | 25 Apr 2016 - 18:04 | HansGeorgZaunick | sketch of apd current measurements. first page: low side measurement, second page: high side measurement w/ current mirror |
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barrel-emc-evo-07032016.pdf | manage | 720.7 K | 29 Apr 2016 - 10:30 | HansGeorgZaunick | slide of meeting from 7-Mar-2016 |
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barrel-emc-evo-18042016.pdf | manage | 474.4 K | 29 Apr 2016 - 10:32 | HansGeorgZaunick | |
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sdiehl_energy_limits_for_the_PANDA_EMC.ppt | manage | 602.0 K | 18 Apr 2016 - 17:13 | HansGeorgZaunick | |
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slice-planning.ods | manage | 48.6 K | 27 Jun 2016 - 10:31 | HansGeorgZaunick | Time table of slice assembly steps and procedures |