1. Potenza Gluing Tests G. Auriemma & C. Satriano

2. Muon Meeting 13/02/2004 LNF G. Auriemma2 The first gluing machine is now in Potenza. It is fully operational after the tuning by Federico and a lot of ------ The suction is not given by the Venturi tube, but by a vacuum pump

3. Muon Meeting 13/02/2004 LNF G. Auriemma3 Panels start flowing in… 3 panels picked-up 22 nd Jan, next 7 arrived 10 th Feb in Potenza

4. Muon Meeting 13/02/2004 LNF G. Auriemma4 Test of the machine As a final check of the gluing machine the gluing of HV bar on final panels has been performed, following the procedure seen during the visit to the LNF gluing laboratory. We tested the procedure on one copper-copper panel and one gold-copper panel, correctly cleaned with propanol (isopropylic alchool) and microfiber cloth. After the prescribed curing time the panel were removed from the machine and measured with a comparator. The precision of the gluing was found to be completely satisfactory. However 50% of the glued HV bar detached easily from the panels when simply pulled by hand 

5. Muon Meeting 13/02/2004 LNF G. Auriemma5 Trace of failed gluing Cleaned with trichloroethylene Copper -Copper panel #150

6. Muon Meeting 13/02/2004 LNF G. Auriemma6 Cleaned with trichloroethylene Cleaned with propanol Uncleaned Gold-gold panel #208

7. Muon Meeting 13/02/2004 LNF G. Auriemma7 On the panel as it came from the factory there is a greasy substance that is hydrophobic to ethanol

8. Muon Meeting 13/02/2004 LNF G. Auriemma8 A simple test suggested by Jean-Sebastian

9. Muon Meeting 13/02/2004 LNF G. Auriemma9 Here the test is repeated on a portion cleaned with Trichloroethylen

10. Muon Meeting 13/02/2004 LNF G. Auriemma10 And here on a portion cleaned only with propanol

11. Muon Meeting 13/02/2004 LNF G. Auriemma11 The grease was not present in the first batch that we received (copper-copper panels #31 and #56) On this panels the glue sticks extremely well even without any cleaning (see samples)

12. Muon Meeting 13/02/2004 LNF G. Auriemma12 Conclusions It appears that something has been changed in the forming of the panels, which should be investigated with the supplier The composition of this greasy layer should be understood in order to evaluate its impact on the performance of the chambers (specially for aging) In our opinion it is not guranteed that this substance is fully removed by cleaning with propanol From our tests to remove it strong organic solvents should be used (same experience at CERN where acetone is used)

13. Muon Meeting 13/02/2004 LNF G. Auriemma13 Unfortunately we are not allowed by safety regulations to use toxic and flammable organic solvents in our lab due to insuffient ventilation, fire prevention and absence of specific drainage for chemicals. We think that if the use of this substance is required by the forming of the panels, it should be fully removed at the factory, before shipping, by cleaning the panels with acetone or trichloroethylen.