CosMO-MuV


CosMO-muv (Cosmic Muon Observer Muon Velocity Measurement) is an experiment that measures the velocity of cosmic muons. Three CosMO detectors are placed at a total vertical distance of 3m. The distance between the lower and the middle detector is 1m, the distance between the middle and the upper detector is 2m. This set-up mimics the muons pathway through our atmosphere and therefore maximizes the chances of detection.

Cosmic particles permanently pass through the detectors. A signal that registers in all three CosMOs, supplies us with the time that the muon took to fly through the allocated distance. This information enables us to calculate the velocity of the muon.

When a charged elementary particle, e.g. the muon, passes through the CosMO's scintillator material, the particles in the scintillator are forced into an excited state. The scintillator's atoms almost immediately return to their ground state and emit the excess energy as light. The light signal is transmitted through optical fibres to the SiPM, where it is converted into an electronic signal by the photoelectric effect. This signal is multiplied in the SiPM and read by the DAQ card.

In order to avoid faulty signals, the muons must fulfill a coincidence condition; only a muon that passes through all three CosMOs is registered. The muon must bypass first the top CosMO, then the middle one and finally the bottom one. Muonic calculates the difference in time between the occurring signals in the individual detectors. The set-up allows three simultaneous measurements: one at 1m, a second at 2m and a third at 3m.

The visualization of the difference in time depending on the distance between the CosMOs lets us determine the velocity of cosmic muons.

 

Setup

Data Structure

Possible Student Exercises

Example Diagrams