Complex sentence: Each accelerated photoelectron that strikes the dynode surface produces several electrons, which are then accelerated toward the second dynode, which is held 90 to 100 V more positive than the previous dynode.
Split into simpler sentences: Each accelerated photoelectron that strikes the dynode surface produces several electrons. These are then accelerated toward the second dynode, which is held 90 to 100 V more positive than the previous dynode.