The Scintillation Gluing Process

    Materials
      -4 Scintillator plates
      -2 batches of epoxy
      -10 grams of resin
      -2.8 grams of hardener
      -Eyedropper, stirring stick, spatula, and small plastic cup
      -Scale
      -2 syringes
      -Vacuum chamber
      -Six, three-inch strands of fiber optics
      -Scissors
      -Scratch resistant gloves
      -Black plastic cover
 

Procedure 1                        Preparing the surface
 

1.) First lay the Scintillator plates on top of the black plastic.  Put on the scratch resistant gloves and carefully peel 2 inches away from one end of the rectangular Scintillator plate, then tear/ cut the access paper away with caution.  TRY NOT TO SCRATCH OR TOUCH (WITH FINGERS) THE SURFACE OF THE SCINTILLATOR PLATE!

2.) Follow the same procedure from step 2, when peeling the paper away from the side opposite the milled potion of the light guide.
 

Procedure 2                        Preparing the epoxy
 

1.) First, place the small plastic cup on the scale; make sure the scale is zeroed. Use the spatula to scoop 10 grams of epoxy resin in to cup, while the cup is on the scale.
2.) Use an eyedropper, and drop 2.8 grams of hardener, with the previous mixture and stir, until mixture is fused together.
3.) Repeat mixture once more for a second batch.
4.) Put both of the cups containing the epoxy into the vacuum. (Vacuum is used to get all of the air out of the epoxy).  Keep vacuum on approximately 30- 45 seconds after the epoxy begins to froth.  Note: Some very small bubbles are ok, however to many is bad.
5.) Let the epoxy set up over night.
 

Procedure 3                        Gluing

1.) First cut two, 24-inch strips of the Permacel tape. (Note: You must allow enough tape so that you can fold the edges of the tape up, to form a well, to epoxy the gap between the two plates.)
2.) Place the strips half way under, (about 1 cm), the Scintillator plate to be glued.
3.) Then take the strands of fiber optics and space evenly along the edge of the Scintillator plate, so that they extend vertically (up), and flat the tape.  Note: It works best to cut the fiber strand with a razor blade, rather than scissors in order to get the flattest edge possible.
4.) Carefully place the other Scintillator plate against the three fiber strands, so that the space between the two plates is the width of the fibers.  This works best milled end of the light guide is placed against the table, and the wide end, is placed gently against the fibers; forming a
5.) Take the fibers out and then repeat for the other plate.
6.) Extract the epoxy out of the cup using the syringe.  You start by injecting the epoxy in one of the corners, between the plates.  Keep a steady pressure on the syringe until the epoxy until it hits the bottom of the plate. Make sure that there are no air bubbles in the epoxy.  Slowly keep injecting the epoxy.  While doing this, you will see a “wave” that will keep moving.  Try not to get ahead of this “wave” to avoid air bubbles.  Keep this up until the entire space between the plates is filled.  Repeat for the second plate.
 

Procedure 4                        Gluing the PMT

1) See Procedure 2
2) Spread the epoxy onto the milled surface of the light guide, with a light coat focusing on the center. Work out all bubbles.
3) Connect the base and PMT.                                                                                                            !!!! CAUTION!!!! > The PMT tends to slip, so hold onto it.
4) Set and support the scintillator plates vertically, so that the light guide is completely level.
5) Put the PMT onto the flush light guide surface so that a ring of epoxy is squeezed out.  Caution!!! The PMT is likely to float around.  Also, make sure the seam is lined up flush with the top of the plate and the base and analog port is lined with the lip.
6) Squeeze the PMT to the light guide surface and keep a close eye so the part doesn’t stray. Capillary action should pull the PMT into place and hold tight
7) Allow approx. 24 hours to set