Minutes of FT upgrade meeting at Daresbury, 7/9/99 ================================================== Present: Tim Greenshaw, Derrick Hill, Graham Houghton, John Morris, Dave Sankey, Terry Sloan, Graham Stokes. 1) Action items from previous meetings ====================================== Graham S -------- Showed us the final design of the support structure for the new planars (4 and 5). He also explained how the pre-amp cover design has been simplified to reduce costs of manufacture in aluminium. Action ------ Graham S to produce drawing of FT shifted forward by 6 cm. Tim --- Acceptable sense wire tensions are in the range 110 to 145 grams. Acceptable field wire tensions are in the range 400 to 590 grams. Graham S will convert numbers into lower and upper allowed frequencies for each cell (i.e. wire length). The Noryl measurements have yet to be completed. A FADC adapter card was given to Dave Sankey. Action ------ Graham S to calculate allowed frequencies for all wire lengths Don --- Don could not be at the meeting. Action ------ Don to locate CAEN and SHV to lemo cables. 2) Bonding of Nomex panels and PCBs (Gary) ========================================== Gary described the problems that have arisen in bonding the PCBs to the Nomex panels. The araldite 2015 that was used conducts electricity. Nobody understands why this is the case; araldite never used to conduct! A new adhesive, electrical encapsulation resin CY1300, has been found and tested. It is sufficiently resistive. Enough PCBs and Nomex have been recovered to manufacture 5 chambers and a sixth is available for recovery if needed. Gary and his team are to be congratulated on the speed with which they have recovered from a potentially very nasty situation; thanks for the hard work you put in recovering the chambers. Thanks also to Derrick for doing the HV testing. 3) Progress with pins (Graham H) ================================ Graham H reported on the various tests that have been done on the pins. The pins available are: The original pins (used to build the planars now in H1. Series 1, the first batch delivered by Medelec about which we complained because of the banding at the inner ends Series 2, the second batch, with thickened gold plating to try and combat the above problem. Cells have been built and tested using all the above. In similar conditions the best performance is seen with the original pins. Series 1 are next best and Series 2 worst. Series 1 and Series 2 tend to draw low levels (few nA) of current at lower voltages than the original pins and breakdown occurs slightly earlier. Sparking was observed to occur at one end only with the Series 1 and 2 pins. The guess is that dirt in the pins is being pulled through to the chamber end of the pins during wiring (the complete wire is pulled off the reel through one of the pins, before being fed into the opposite pin). A test is to be done with a cell in which the wire was always fed from the inside of the chamber. Gary pointed out that wiring like this takes 1 1/2 times longer than using the original procedure. Careful examination of several Series 1 and 2 pins showed the presence of small (apparently metal) spikes and also flaking of the gold plate. A cleaning procedure is to be tried (using Tryclone) to see if this can remove any of the dirt/swarf that is probably causing the above problems. Enough new pins of the Series 3 type to build a complete planar are to be ordered. We will require with improved cleaning procedures. We will also order a few pins with rounded ends so we can test these. If they prove to be better, subsequent chambers will be built using these. Action ------ Gary and Graham H to perform further tests of pins. Gary to talk to Ray Thompson about wiring. Tim to order more gas. 4) State of finances (John) =========================== Follwing the meeting, John was able to disentangle some comfusion with the accounts. Some items that should have gone onto the FT upgrade account have been put onto H1 M&O. The upshot is that we have spent all bu about 10k of the money available for the FT upgrade; the bottom of the barrel is showing! Action ------ Graham H to order more Noryl blocks only if construction of first chamber reveals more will be necessary. 5) Chamber production (All) =========================== Graham H showed us new schedules. If all goes well we can produce 5 chambers by April 2000. Action ------ Tim to organise testing of chamber, 1st week of October. 6) Software Plans (John) ======================== There is to be a software meeting on 17/9/99 at Lancaster.