Trigger (physics)

In physics, a trigger is a system that controls the data collection of an experiment. In experiments it is often not possible or not important to continuously record all measured values. In this case, only some of the measured values ​​are read out and a decision is made based on this when the remaining data should also be read out. Triggers are especially important in particle physics.

For example, in the experiments in the Large Hadron Collider, particle collisions take place up to 40 million times per second - analyzing all of them would by far exceed the available storage and computing capacities. Therefore, a few hundred to a few thousand per second (depending on the experiment) must be selected from these collisions, which are completely analyzed and stored. This is possible because many interesting processes like the production of Higgs bosons happen less than once per second. The trigger system is faced with the task of picking out exactly those collisions that are important for the experiments from the multitude of collisions.

literature

Volker Lindenstruth, Ivan Kisel: Overview of trigger systems. In: Nuclear Instruments and Methods in Physics Research A, Vol. 535 (December 2004) pp. 48-56, doi : 10.1016 / j.nima.2004.07.267 (English).