1. Collaboration of TE-VSC-SCC with straw-material working group NA62 Wil Vollenberg and Delphine Letant Delrieux TE-VSC-SCC NA62 straw working group meeting; 22-03-2010W.V. & D.L.D. - Introduction - Coating activities - Permeation results

2. INTRODUCTION Motivation: -Reduction of permeation of straws is important for gas load on pumping groups. - Fraunhofer coated Hostaphan GN 4600 foils gave a low Barrier improvement factor (BIF) CO 2 : max 7 - Morphology of these films is not uniform NA62 straw working group meeting; 22-03-2010W.V. & D.L.D.

3. INTRODUCTION NA62 straw working group meeting; 22-03-2010W.V. & D.L.D. Our commitment in collaboration: - Continue measuring permeation of coated PET - making coatings on PET Goal of study: -Influence of coating thickness on BIF: different thickness of Cu coatings on Hostaphan GN 4600 - Influence of choice of coated side of film on morphology and permeation and coating adherence.

4. Coating activities NA62 straw working group meeting; 22-03-2010W.V. & D.L.D. SAMPLECOATINGPERMEATIONADHERENCESEM Host. Untreated sideCERN Cu 49 nmongoing X Host. Treated sideCERN Cu 49 nmXongoingX Host. Untreated sideCERN Cu 150 nm XX Host. Treated sideCERN Cu 150 nm XX Note: Treated side: chemical treatment by PET producer. In general this treatment enhances adherence and therefore this side is used for side to be coat. But chemical treatment has influence on Surface: by XPS we found traces of Na, S, Si

5. Permeation System NA62 straw working group meeting; 22-03-2010W.V. & D.L.D. Membranes Hostaphan Cu_49nm Membranes for permeation measurements Reference: Hostaphan without coating

6. Experimental results by accumulation method NA62 straw working group meeting; 22-03-2010W.V. & D.L.D. V= volume of accumulation chamber [l] l= thickness of the membrane [cm] A= surface of the membrane [cm 2 ] P gas = injection pressure [Torr] BIF CO2 = 9 BIF Ar = 6

7. Surface analysis results (XPS): Hostaphan NA62 straw working group meeting; 22-03-2010W.V. & D.L.D.

8. Future activities NA62 straw working group meeting; 22-03-2010W.V. & D.L.D. Permeation (Ar and CO 2 ) determination of:  Hostaphan GN 4600 coated on untreated side (ongoing)  Excell 532:  Cu_50nm+Au_20nm  Cu_100nm+Au_20nm  Cu_50nm  Cu_100nm