17.03.99 A.Komar Status Report ( LPI,Moscow) Main point: In January 1999 LPI started regular work on the production of the EST boards for HEC on the basis of new (Canadian) technology. I. Preliminary steps This start was preceded by the manufacturing of 10 control electrodes in November of 1998, which went through the necessary tests at MPI and were considered as satisfying QC specification. Since that moment LPI group made further steps in preparing lab for series production of the electrodes and adjusted for this purpose various tooling devices. In particular we modified our thermal chamber, which is an equivalent of oven at TRIUMF laborato ry, our cutting devices and made many experiments with the press searching for the optimal regime of gluing with Russian glue. We found one regime which satisfied us: so called two stage regime. At the first stage (during 3 hours) the pressure was kept relatively low - 7 bars, at the second stage (during 1 hour) the pressure was higher - 15-17 bars. The working temperature was 130 C. We also looked for various possibilities to make efficiency of electrode gluing with the press higher by increasing its load. We showed that it was possible to glue up to 8 electrodes in the press simultaneously. But our stock of glass filled teflon sheets did not allow us at that moment to realize it. So we limited ourselves to 7 EST boards glued in one batch. Recently the situation has changed with receiving the parcel from TRIUMF containing the awaited teflon sheets. II. Where are we now? After preliminary steps described above it was possible to start real production work. As a rule we went forward with the pace 7 EST boards/day. Sometimes slightly less. Altogether from Jan 11 to Mar 12 (two months) we manufactured 261 electrodes, that is roughly speaking 130 EST boards/month. 19 electrodes were rejected by various reasons: mecanical defects (small tears at the edges, folds, wrinkles, bowing effects), electrical defects (shorts), other defects. Rejected electrodes constituted about 8% of all produced EST boards. Gradually percentage of the deficient electrodes became smaller. Selected "good" electrodes were of the following varieties: 111 EST boards for front modules 131 EST boards for rear modules This amount is sufficient for more than 2 front modules and (formally) about 4 rear modules However there is an important comment to this last statement. Due to the shortage of the CLK foils for the gaps 25-32 (with respect to the gaps 33-40), we had during last weeks, total amount of rear EST boards, mentioned above, really corresponds to 2 full modules plus 1 rear module almost complete (only 7 EST boards are lacking). The situation will be improved after new portion of CLK foils will be in our disposal (the parcel is already in Moscow). From the existing rear EST boards the set of 36 boards was dispatched in March 99 to MPI. III. HV testing In parallel with electrode production long-term HV tests of the manufactured electrodes were organized. We have recently modified computer controlled HV stand; its capacity was enlarged to 106 electrodes tested simultaneously (sufficient to test EST boards for two modules at a time). Leakage currents were written down by the computer every ten minutes. Leakage currents stabilized rather quickly (after a few hours). Their subsequent dynamics was rather slow with tendency of current values to diminish. We also observed dependence of leakage currents on the humidity (currents grew when humidity grew). The current values which are cited below corresponded to humidity in the range (45-50)%. The actual observed leakage current lay in the region (10-20) nA. It was difficult to estimate simple averaged values, because currents varied in rather irregular way. Unfortunately during HV testing we had three cases (among 150 tested electrodes) of inadmissibly high leakage currents (practically shorts).These shorts happened correspondingly on the 1-st, 2-d and 5-th day of testing. This situation was unusual to us. Shorts, if they happened before, occurred almost immediately during the short-term tests. The possible reason is a quality of the latest party of kapton, which was not pre-tested industrially for HV. From this moment we shall strictly ask our producer to test kapton for HV before covering it with glue. At the final stage we also made corona tests of the produced EST boards. So far we had no examples of board rejection on the basis of this test. Altogether we have tested 45 EST boards for rear modules and 105 EST boards for front modules EST boards for two front modules will be prepared during this week for the dispatch to TRIUMF and Dubna correspondingly. IV. What can be expected? In future LPI group plans to produce EST boards with a rate 8 EST boards/day. This could bring us nearer to the desirable figure 160-170 EST boards/month. As a rule we plan to manufacture in succession EST boards for two modules of one type and then change to manufacturing of two modules of another type. Certainly the variation in schedule is possible. The capacitance of our modified HV stand allows us to make long-term HV test of the EST boards for two modules simultaneously. Problem of passing through the customs (in both ways) is still very acute. It is even not the question of wasted time, but the question of vague and uncertain regulations. In this sense it is preferable to make the frequency of dispatches smaller: say one in two month or may be one in three month. Funding of Russian institutes is another very serious problem In particular planned funding of LPI group in 1999 is 1/3 from the required.