Minutes of the Tracker Technical Meeting
March 6, 2002
Action Items:
Tom suggesting finishing the Tracker piece parts and assembly drawings at SLAC. That way Luisella can concentrate on the tooling drawings. Monday in Pisa, Ossie will sit with Luisella to discuss how to complete the drawings.
There was a discussion about plans for the live trays of the engineering model. Robert wants to keep them separate at all times from the mechanical/thermal tower. Therefore, the working plan is to make a live mini tower of four trays and 3 x,y planes of SSDs, enclosed by aluminum walls. Only the top tray would have converter (thick tungsten). Robert suggested using an existing tray for the bottom, but Sandro pointed out that it would cause problems for the assembly fixturing and schedule. Therefore, we decided to make the bottom tray of the mini tower a normal no-converter tray.
Robert agreed to send the test plans for live trays to Sandro and the requirements for them. Robert pointed out that they don’t need the best detectors. In fact, detectors with higher leakage current and higher numbers of dead channels could be used in the engineering model.
Tom promised to get 15 connector pairs ordered, since not enough are in hand for the present engineering model plans.
Erik said that he is trying to get the vibration test data from Ames. Ossie said that he could go down with some Zip disks. However, Erik said that the data need to be converted at Ames to ASCII Matlab format from the present binary format. Ossie and Erik will try to call the guy at Ames. Erik hopes to have analysis results by the end of the month.
Tom talked about his plan to refit the bottom of the existing tower in order to repeat the random vibration test at qualification levels. The idea is to add inserts to the bottom tray to increase the number of fasteners from the sidewalls. Also, inserts will be put in the bottom row of holes in the sidewalls. He said that we can reuse the sidewalls despite the damage from the previous test, since the holes will be drilled out for the inserts. Tom needs to know what the inserts look like and how to get them installed. Erik said that he has a new drawing.
Ossie asked why we want titanium for screws. The main reason is mass and radiation length (3.56 for titanium versus 1.76 for steel). Titanium also has less diffusion bonding, but that probably is not an issue for us anyway. Two grades of titanium are available with high torque heads. Ossie or Erik will send Robert the total mass of the screws to better judge the impact of the materials choice.
Tom said that only 2 sidewalls have been taken off the tower so far. The work is slow because the hex sockets are stripped in many of the screws. There is no evidence of damage to the tower so far except for the screws holes in the sidewalls where the screws into the bottom tray backed out. Also no rubbing at all is evident between sidewalls and trays except on the bottom tray where the screws backed out. Tom said that they would get it completely disassembled before leaving for Italy.
Ossie reported that he is talking to vendors about the encapsulation protection caps for the TMCM screw holes. Teledyne needs them now. He said that Teledyne has enough usable pitch adapters for the engineering model.
Erik said that he will get his proposal to Tom this afternoon to change the contract so that they may order K13d material for testing.
Erik said that the aluminum cores still are not shipped from Hytec due to uncertainty about the shipping procedures. Tom said to send the cores to SLAC and Tom will ship them. Erik will double check the exact number of cores for Sandro. He believes that there should be 18 standard cores left pluse 5 top/bottom ones. 2 heavy cores are at Hytec (8 were shipped to Italy). There remain 3 heavy and 1 light cores in Italy.