ANNIE tank geometry¶
The ANNIE water volume is a 9' (diameter) x 13 ft (tall) upright cylindrical tank.
It will be instrumented with the 52, 10" WATCHBOY PMTs. The exact configuration of the PMTs is not yet determined, but we would like to achieve as uniform coverage as possible.
Technical drawings of the ANNIE tank can be found here
Drawings of ANNIE in the SciBooNE Hall can be found here
Building a simple LAPPD model in GEANT or RAT-PAC can start out as simple as an 8.3" x 8.3" x 0.728" (thick) tile with 8"x 8" active area.
Pictured below is a more detailed picture of the stack-up for an LAPPD tile. The tile assembly is a flat glass package with surface dimensions of 229.1 mm in the strip direction by 220 mm transverse. The active area is 203 mm by 203 mm (8 in. by 8 in.). The tile is made from glass layers stacked to form a rigid structure when compressed by atmospheric pressure.
The vacuum volume is enclosed by the 2.75 mm-thick top window, a standard plate glass thickness. The photocathode is on the bottom surface of the window, facing the top of the upper MCP. Here is a drawing of the footprint for the top-window:
The anode plate with silver microstrips on its top surface, serves as the bottom of the vacuum volume, and is also 2.75 mm-thick. A rectangular border of 5.08 mm (0.200 in.) width, cut from a standard thickness glass plate, forms the sidewall of the volume. The sidewall is sealed to the anode plate over the microstrips with a glass frit seal. The metal microstrips extend beyond the sidewall so that contact can be made with neighboring tiles or the digitization printed circuit cards at the end of a tile-row. Pictured below are drawings showing the footprint of the anode and dimensions of the side-wall: