31. The light is focused onto the photocathode of a photomultiplier tube that triggers an electron avalanche. 32. We apply pressure tests to the photomultiplier tubes . 33. The fluorescence from the sample is then collected by a high-sensitivity detector, such as a photomultiplier tube . 34. They're called photomultiplier tubes , and they're sunk several kilometers deep into the ice at the South Pole. 35. Photomultiplier tubes , too, are often used for increasing the intensity of the output signal to a usable level.36. Are the photomultiplier tubes operated continuously? 37. This statement in the first paragraph of the photomultiplier tube article struck me as possibly outdated and unsubstantiated: 38. The water tanks were sandwiched between three scintillator layers which contained 110 five-inch ( 127 mm ) photomultiplier tubes . 39. A : The glass used in the photomultiplier tubes is only several millimeters thick, and very weak against shock. 40. Notice the two technicians and the size of each photomultiplier tube ( enhanced by the big lens assembly ).
