MAPMT H7546B Anode Current Response Study for an ILC SiD Muon System Prototype

The proposed Silicon Detector concept for the International Linear Collider has a barrel and end cap muon systems. The scintillator based muon system prototype has 256 scintillating strips, wavelength-shifting fibers, and clear fibers connected to multianode photo multiplier tubes (MAPMT). Six Hamamatsu H7546B tubes were used. To understand strip output, each of 384 MAPMT outputs was independently measured at a given luminous flux and the same photocathode to anode voltage of 800 V. For the test, a custom made source of light was used. The anode currents have a wide spread; for all tubes the maximum value is 5.23 times larger than the minimum value. The MAPMT cross talk was measured for one of the central inputs. The maximum cross talk value is about 4.9%. The average cross talk for the nearest four neighboring channels is 3.9%, for the farther four 1%. To assure reproducibility and repeatability of the measurements a double reference method was used.