Minutes of feedthrough meeting of 7 January, 2002. ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ Present: Pof, GV, FH, PB, RKK, MGF, ASD, ML *) Milestones - 36 more pincarriers (18 of each type) arrived today. We now have in total 214/275 7-row and 212/275 8-row pincarriers. Pof has contacted Pete Tardiff to verify that Glasseal agrees with these numbers. It was also decided today that we will not attempt to cut the pincarrier order short, we will receive the full original order. - Pincarriers continue to be cold cycled and leak checked. Lots more to go... - ft24 (a Standard) showed a short between two channels (channels 13 and 14 of slot 4) during the cold test. The short is not present when the feedthrough is warm. The resistance between pins 13 and 14 on side A was measured (cold) to be 1.0 Ohms, and 2.3 Ohms on side B. This suggests a short originating in the connector at the cold end of the vacuum cable in slot 4A. ft24 will be opened (PB will use a dremel on the bellows) and, to be safe, both vacuum cables in slots 4A/B will be replaced. All parts excluding the two vacuum cables (and maybe the Rohacell) should be recoverable. During the cold test this week of ft25 (10 January) a similar short was found on slots 11, so ft25 will also require opening for repair. Fiona checked the logs to see if the vacuum cables failing with "opposite channel" shorts might all be from the same batch. There have been seven such failures so far, and all are from the 27 November 2000 batch of 438 vacuum cables. There are 167 vacuum cables which remain unused from that batch. To be safe, all remaining vacuum cables (not just those from the 27 November 2000 batch) will now be subjected to more rigorous testing (cold, HIPOT, etc) before use. We will try testing the defective cables from ft24 and ft25 to see if we can reproduce the failure with the additional tests. - Tom Muller has the material certs for the two Sandmeyer batches of pincarrier steel, and will send them to us this week. Tom will try to obtain the material certs for the CERN steel from Dave Rahm. *) The revised scheme for protecting the pigtails during feedthrough construction and installation seems to be working well, although we should continue to keep a sharp eye out (that leaves me out...) for damaged pigtail cables. The new procedures will be added to the QA/QC document. These procedures might also be usable for feedthrough installation. *) The defective pincarrier that was welded into a flange (see 10 Dec 01 minutes) was checked with the electronics shop's MegaOhmmeter. The pin with the gold plating in the glass bead has an insulation resistance to ground of about 10 Giga Ohms; typical for good pins is about 10 Tera Ohms. Note that the inter-channel insulation resistance specification for the vacuum cables is 500 Mega Ohms. Since removal and replacement of the defective pincarrier is not significantly risky, we will go ahead and replace that pincarrier even though it is unlikely to cause problems. *) 27 flange heaters have been completed so far, except for the RTD and power connectors. Once the connectors are installed, each heater will be subject to a set of tests. A jig will be designed and built such that the RTD and power connectors will be plugged into the jig and the following tests conducted: -) Measure resistance of the six resistors in parallel (should be ~12.5 Ohms). -) Check for power-wire shorts to ground. -) Measure resistance (and continuity) of each of the two legs of each 4-wire RTD. -) Check for RTD shorts to ground. -) Check for shorts between power wires and RTD's. -) A power supply will be used to provide 30 Watts of power to each resistor for five minutes (30 Watts is the military spec for the resistors); the resistance of each RTD will be checked and recorded at the beginning and end of the five minute power test to ensure that the resistances correctly track the temperature rise. *) All CDD drawings except one have now been updated with the most current (and final) versions. The one remaining should be updated early this week. The QA/QC manual will be updated with the new drawings. *) For the upcoming LARG week (4-8 February) it is not necessary to send someone simply for the sake of reporting on our feedthrough production status, however it might be worth being at CERN to query Pierre and others on what will be required of us for the ASSO (we definitely should not volunteer what we intend to present). Michel should also check with David Lissauer that we are not duplicating efforts in preparing material for the ASSO. Margret may be at CERN to cover other interests (test beam, etc) and Richard could also attend, but not until later in the week. If need be, pof's slides for the C&C meeting could be made available to Pierre for presentation. *) Michel is still negotiating the optimum way of paying BNL for our share of the pincarrier steel. *) A gathering is planned for 3:30 Thursday 17 January in the TRIUMF lab to commemorate the project half-way mark. Agenda for next week ^^^^^^^^^^^^^^^^^^^^ - Milestones - progress on ft24 repair (vacuum cable short...) - additional test plans for vacuum cables - plans for 4 - 8 Feb LARG week - plans for the week - AOB