The box’s output sends an impulse to an external counter, when two (or optionally three) of the inputs receive an impulse simultaneously (i.e. within 1 microsecond).
This allows you, for instance, to detect the gamma cascade in the decay of Co-60 or the fact that the annihilation quanta from Na-22 are radiated at 180° to each other.
The coincidence box is also used in the study of cosmic radiation.
It connects to two or three single GM tubes. The output impulses are registered by a GM counter 513600, counter 200250 or via a Pasco digital adapter PS-2159.
Comprehensive instructions included.