Photomultiplier Plateaus

An efficient photomultiplier (PMT) is one that yields a high count number with a minimum amount of noise. By applying a range of voltages to a PMT and plotting them against the count efficiency at each level, one will see a plateau. At the start of this plateau, the efficiency of the PMT is greatest because the count rate is high and applying more voltage will only contribute more noise.

Two brands of PMT's were used:

• Photonis plateaus

• Hamamatsu plateaus