Minutes of feedthrough meeting of 10 December, 2001. ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ Present: Pof, AD, FH, PB, ML *) Milestones - 48 pincarriers (24 of each type) were shipped from Glasseal to uvic on Friday 7 December. - ft22 and ft23 (both Standard ft's) were cabled and welded last week, along with four flanges. Cold cycling of pincarriers continues... - 21 feedthroughs are now at CERN. 10 feedthroughs at CERN (ft00 -> ft09) are in the process of ownership transfer; the traveler sheets for those feedthroughs have been turned over to Pierre, but we are waiting for him to generate the necessary forms for ownership transfer. - Weeks 3 and 10 December reports from CERN: 3 Dec: Finished electrical tests on FT15. Ran analysis of FT15 data; found one errorenous slot - slot12b. Leak checked Bellows of FT11. Pumped down funnel of FT13. 4 Dec: Remeasured slot12b and reran analysis; data looks fine. Leak checked funnel of FT13. 5 Dec: FT18,19,17,21 arrived at CERN. Ran electrical tests of FT13. Pumped down funnels of FT18,19 6 Dec: Leak checked funnels of FT18,19. Ran electrical tests of FT18. Pumped down bellows of FT13. 7 Dec: Electrically tested FT19. Leak checked bellows of FT13; 1.8x10^-8 mbar-l/s leak found in warm flange / seal ring weld. 9 Dec: Releak checked bellows of FT13; leak persists. Pumped down bellows of FT13 and funnels of FT17,21 10 Dec: Electrically Tested FT17,21. Releak checked bellows FT13; still found leak. 11 Dec: Worked with Aboud on Feedthrough installation mockup; installation took about 6 hours. Without problems, could be done on mockup station in 3-4 hours. Pumped down bellows of FT18,19. 12 Dec: Leak checked FT18, 19. Pumped down bellows of FT17,21 13 Dec: Leak checked Ft17,21. Printed final reception forms. Cleaned up lab. Locked up all 'thievable items'. 14 Dec: Gave Roy set of keys, returned CERN car. John leaves for UK; back to UVIC in one week. Dropped off dosimeters. 16 Dec: Greg flies back to Victoria. *) ECC is officially scheduled to be delivered to CERN on 11 February 2002, however most believe that is unlikely. ECA delivery is scheduled for 31 July 2002 (also considered unlikely). A minimum of one month will be requred from the time of delivery to the time of feedthrough installation. *) One pincarrier has developed a side wall leak after welding into a flange. That pincarrier will be machined out of the flange and replaced. *) Work is currently underway (at the highest priority) to bring the documentation up to date. Among the documentation items are: - an updated QA/QC document to be put on EDMF, including procedures for reception tests, firm numbers for pass/fail criteria (leak rates, etc) and an appendix on all TIS related tests and milestones. - all material certifications, to be put on EDMS - all weld plans, to be put on EDMS *) PB pointed out that the leak checks done at Glasseal are done to the level of 1 10^-9 mbar-l/s. We will use that figure as a pass/fail criterion for leak rates per flange for pincarriers welded into flages (and in finished feedthroughs), and also on leak rates per individual pincarrier, although in practice any pincarrier found with a detectable leak (~4 10^-10 mbar-l/s) would be set aside. *) There was a problem with the pincarrier 1000 V HIPOT test jig, with the pincarrier body not being grounded properly and consequently the tests were not picking out any potential ground shorts or inadequate isolation resistance. Note that this test is used primarily as a cleaning aid to find small bits of metal at the base of the pins. One pincarrier that was tested with the defective jig and subsequently welded into a flange has been found to have some gold plating on the glass bead on one pin, and consequently can only pass a HIPOT test at 630 V, failing at 800 V. Pof will check the isolation resistance of this pin to see how it compares with the isolation resistance specs of the vacuum cables. If the isolation resistance is too low, the pincarrier will be machined out and replaced. *) There is some question whether or not the RF seals that we had pre-made (cut to length and soldered to form a loop) will fit into the groove of the seal ring, since the soldered connection bulges too much to fit easily into the groove. The price of 250 feet of uncut RF seal material (sufficient for all 50 ft's) is less than CDN $700, so we will purchase the uncut material to have in hand at CERN in case the pre-made loops don't work out. *) Horst Oberlac has requested an inventory of gold and silver content in all LArg components, to investigate potential activation problems. For end cap signal feedthroughs, we have responded with the following note: The following itemizes the known gold and silver content in each of the end cap signal feedthroughs (there are 25 signal feedthroughs in each end cap): *) The pincarriers are plated with 1.3 micro-m of gold. The gold content of a 7-row pincarrier is estimated to be 0.83 gm, and the gold content of an 8-row pincarrer is estimated to be 0.94 gm. The total gold content of the four 7-row and four 8-row pincarriers in each of the feedthroughs is then estimated to be 7.1 gm. *) The vacuum cables have components which are gold plated. The ground shields are plated with 1.27 micro-m of gold, and the pin sockets are plated with 1.02 micro-m of gold. The total gold content of a single vacuum cable is estimated to be 0.55 gm; the total gold content of the 30 vacuum cables in one feedthrough is then 16.5 gm. *) The vacuum cable pin sockets are soldered. The silver content (if any) in the solder is unknown. A material analysis of the solder could be obtained if required. *) There are 30 pigtail cables (harness B) in each feedthrough. Information regarding the gold content (the ground shields and pin sockets are gold plated) and silver content of those cables should be obtained from the Orsay group. *) The power resistors of the ambient flange heaters contain no gold or silver. The gold or silver content of the other heater components, such as the fuses and temperature probes, is still under investigation. An update to this document will be distributed if gold or silver are found in any of those components. Agenda for next week ^^^^^^^^^^^^^^^^^^^^ - Milestones - status of documentation - plans for the week - AOB