1. B.Satyanarayana, TIFR, Mumbai For INO Collaboration
Glass characterisation techniques used in the Resistive Plate Chamber development
B.Satyanarayana, TIFR, Mumbai
For INO Collaboration

2. Thickness variation of the float glass
B.Satyanarayana, TIFR XVII DAE-BRNS High Energy Physics Symposium, December 11-15, 2006, IIT Kharagpur

3. Density comparison of glasses
B.Satyanarayana, TIFR XVII DAE-BRNS High Energy Physics Symposium, December 11-15, 2006, IIT Kharagpur

4. SEM scan of Japanese glass
Japanese glass is the best among the three samples in terms of the surface quality. It didn’t show any surface cracks or structural defects.
B.Satyanarayana, TIFR XVII DAE-BRNS High Energy Physics Symposium, December 11-15, 2006, IIT Kharagpur

5. SEM scan of Asahi glass
Asahi glass’s surface quality is satisfactory and is comparable to that of Japanese glass. The samples has shown occasional surface cracks.
B.Satyanarayana, TIFR XVII DAE-BRNS High Energy Physics Symposium, December 11-15, 2006, IIT Kharagpur

6. SEM scan of Modi glass
Surface scans of Modi glass were found to be unsatisfactory. Shown a SEM scan with a diffraction pattern.
B.Satyanarayana, TIFR XVII DAE-BRNS High Energy Physics Symposium, December 11-15, 2006, IIT Kharagpur

7. SEM comparison of glasses
B.Satyanarayana, TIFR XVII DAE-BRNS High Energy Physics Symposium, December 11-15, 2006, IIT Kharagpur

8. Transmittance comparison of glasses
Transmittance test of various glass samples over the UV and visible light spectrum was carried out.
As shown in the figure, the Japanese glass shows about 10% better transmittance over local brand glasses.
B.Satyanarayana, TIFR XVII DAE-BRNS High Energy Physics Symposium, December 11-15, 2006, IIT Kharagpur

9. Glass reflectivity technique
Due to the technique of float glass making, the quality of two glass surfaces is not identical.
It is advisable to keep two smooth surfaces of the top and bottom electrode glasses, facing the gas volume.
We have devised a scheme using the reflectance of glass surfaces for the UV radiation to mark the smooth and rough surfaces.
B.Satyanarayana, TIFR XVII DAE-BRNS High Energy Physics Symposium, December 11-15, 2006, IIT Kharagpur

10. Side comparison of glasses
B.Satyanarayana, TIFR XVII DAE-BRNS High Energy Physics Symposium, December 11-15, 2006, IIT Kharagpur

11. Side comparison of glasses
B.Satyanarayana, TIFR XVII DAE-BRNS High Energy Physics Symposium, December 11-15, 2006, IIT Kharagpur

12. EDS comparison of glasses
Shown in table below are fractional percentages of weights of various elements present in the glass samples obtained using Energy Dispersive X-ray Spectroscopy (EDS) technique.
Within the instrument tolerances, we find that the glass samples show consistent values of various constituent elements among them.
B.Satyanarayana, TIFR XVII DAE-BRNS High Energy Physics Symposium, December 11-15, 2006, IIT Kharagpur

13. Aging: AFM and SEM scans
Damaged surfaces
AFM
Raw surfaces
SEM
B.Satyanarayana, TIFR XVII DAE-BRNS High Energy Physics Symposium, December 11-15, 2006, IIT Kharagpur

14. Aging: Element analysis
Atomic%
Oxygen
28.45
Fluorine
40.31
Sodium
11.82
Magnesium
2.00
Silicon
17.41
Element
Atomic%
Oxygen
64.19
Fluorine
4.17
Sodium
6.29
Magnesium
2.11
Silicon
23.25
Damaged glass
Raw glass
B.Satyanarayana, TIFR XVII DAE-BRNS High Energy Physics Symposium, December 11-15, 2006, IIT Kharagpur

15. Aging: AFM comparison of surfaces
Damaged electrode surfaces
Cleaned electrode surfaces
Deposits on damaged glass surfaces are loose and flaky
B.Satyanarayana, TIFR XVII DAE-BRNS High Energy Physics Symposium, December 11-15, 2006, IIT Kharagpur

16. Summary and outlook
Many of the material science tools were used during the development of Resistive Plate Chambers
Found useful both for characterisation of raw glass electrodes as well as for analysis of damaged samples
Will also be used during RPC production for example to determine the appropriate glass surface – rough versus smooth
B.Satyanarayana, TIFR XVII DAE-BRNS High Energy Physics Symposium, December 11-15, 2006, IIT Kharagpur