In a particle accelerator, nuclei shatter into fragments like a porcelain cup dropped on the floor. Each fragment flies through silicon wafers, which register the impact and its strength. But to distinguish a real signal from random noise, you need a threshold: below it, readings are considered interference.
The FOOT experiment uses six silicon wafers, each 150 micrometers thick, stacked in three layers. Previously, thresholds were set by cross-checking with other detectors, but that's like fixing a watch by glancing at the neighbor's — errors pile up. Now, a method has been proposed to set thresholds for each sensor individually, without looking at the others.
The resulting threshold values are like the zero mark on a ruler. From there, you can move up or down, testing how efficiently the detector catches each individual ion. And if you combine these settings with particle trajectory information, the picture becomes clearer: you can see exactly where the fragment passed and how strong the signal was.
Silicon detectors work like extremely sensitive scales: a passing particle leaves a charge that can be measured to within fractions of an electron.