FAQ - Optical Coupling Medium
Posted: Fri Mar 24, 2006 2:58 pm
A Few Options for Coupling a Scintillator to a PMT:
1) Use Dow Corning Sylgard 184 two-part silicone resin. The cured resin is clear out to the UV, and doubles as a glue to hold the scintillator in place. Obviously, there will be no creep problem when it sets. This is what I use to put scintillation probes together. As a bonus, you can use this stuff, some ZnS(Ag) phosphor, and a hunk of lucite/perspex/plexiglas to make a servicable fast neutron scintillator. Check out the pics section for a photo of one...
2) "Pocket Pond" Silicone Gel - This is a water-clear, extremely viscous silicone gel sold at pocketscope.com. For a reasonable price, you get about 1 fluid ounce, enough for all the scintillation probes one would care to make.
2) Model Car Silicone Differential Fluid - A seller on Ebay offers Mugen Silicone fluid for model car differentials. The thickness you want is the 100000 (five zeros!) weight. It is extremely viscous, so there will be less of a problem keeping it in place between scintillator and PMT.
3) Silicone Vacuum Grease - This stuff is usable as a last resort. It is translucent, but if used properly (an extremely thin layer), any scattering due to the turbidity will be offset by the decreased interface loss between PMT and scintillator.
1) Use Dow Corning Sylgard 184 two-part silicone resin. The cured resin is clear out to the UV, and doubles as a glue to hold the scintillator in place. Obviously, there will be no creep problem when it sets. This is what I use to put scintillation probes together. As a bonus, you can use this stuff, some ZnS(Ag) phosphor, and a hunk of lucite/perspex/plexiglas to make a servicable fast neutron scintillator. Check out the pics section for a photo of one...
2) "Pocket Pond" Silicone Gel - This is a water-clear, extremely viscous silicone gel sold at pocketscope.com. For a reasonable price, you get about 1 fluid ounce, enough for all the scintillation probes one would care to make.
2) Model Car Silicone Differential Fluid - A seller on Ebay offers Mugen Silicone fluid for model car differentials. The thickness you want is the 100000 (five zeros!) weight. It is extremely viscous, so there will be less of a problem keeping it in place between scintillator and PMT.
3) Silicone Vacuum Grease - This stuff is usable as a last resort. It is translucent, but if used properly (an extremely thin layer), any scattering due to the turbidity will be offset by the decreased interface loss between PMT and scintillator.