Particle identification in detectors

In summary, lead-scintillator detectors can discriminate between electrons, muons, and mesons. Different energies can be estimated for electromagnetic and hadronic showers. Cerenkov counters measure the Cerenkov light angle to select the particle velocity. Electric fields have been used as velocity detectors.
  • #1
ghery
34
0
Hello:

Can anyone please tell me how do they identify the particles in the detectors?+, for instance, how do you know if an electron is an electron and not a muon or some other negative charged particle in a detector (without using magnetic fields)?
 
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  • #2
ghery said:
for instance, how do you know if an electron is an electron and not a muon or some other negative charged particle in a detector (without using magnetic fields)?
I do not know why you would like not to use a magnetic field : it is very convenient to measure the ratio charge/momentum. Anyway, muons and electrons will give different Cerenkov light (you will need to choose the medium optical index in advance, according to the range in momentum you are interested in). If your muon is slow enough you may be able to measure the time of flight accurately enough to distinguish with an electron. Also, they produce different electromagnetic interactions in heavy material at a given incident energy (the showering process for muons in calorimeters requires much more energy than for electrons).
 
  • #3
Hi ghery-
A high energy electron going into a 20-radiation-length lead-scintillator calorimeter sandwich would lose all its energy and stop. A muon of the same energy would lose only about 2 MeV per gram per cm-squared of material (Bethe-Bloch de/dx). Many years ago, I used time of flight (with 1-ns time resolution) to separate muons and pions in a low-momentum beam.
Bob S
 
  • #4
ghery said:
...(without using magnetic fields)?

Two fast charged particles of the same velocity make the same ionisation traces so using some magnetic filed and other things to distinguish the particle masses and charges is important.
 
Last edited:
  • #5
When I wrote "without using magnetic fields" what I really meant was if there was any other way to distinguish for example the velocity of a charged particle besides the use of magnetic fields?
 
  • #6
Hi ghery-
Lead-scintillator detectors can discriminate between electrons (electromagnetic showers) muons (minimum ionizing track) and mesons and hadrons (hadronic showers). Energy can be estimated for electromagnetic and hadronic showers.
Cerenkov counters (mentioned above) can measure the Cerenkov light angle (Cerenkov ring detectors) to select the particle velocity. Varying the pressure in high-pressure gas Cerenkov detectors has been used to identify particles by varying the threshold particle velocity.
Electric fields, often in Wien filters, have been used as velocity detectors. See
http://en.wikipedia.org/wiki/Wien_filter
Particle time-of-flight (mentioned above) between two plastic scintillators or Cerenkov radiators on photomultiplier tubes has been used to select particle velocities.
Bob S
 

1. What is particle identification in detectors?

Particle identification in detectors is the process of determining the type of particle that has passed through a detector. This is done by analyzing the energy, charge, and other properties of the particle.

2. How do detectors identify particles?

Detectors use various methods such as ionization, energy loss, and time-of-flight measurements to identify particles. These methods allow for the determination of a particle's mass, charge, and velocity, which can then be used to determine its identity.

3. What types of detectors are used for particle identification?

There are several types of detectors used for particle identification, including time projection chambers, drift chambers, silicon detectors, and calorimeters. Each type of detector has its own strengths and limitations, and they are often used together to provide more accurate results.

4. What are some challenges in particle identification?

One of the main challenges in particle identification is separating similar particles with similar energies, such as electrons and photons. Another challenge is dealing with background noise and interference from other particles in the detector.

5. Why is particle identification important in scientific research?

Particle identification is crucial in scientific research as it allows us to better understand the properties and behavior of particles. By accurately identifying particles, we can gain insights into the fundamental laws of nature and how the universe works. It also helps us in studying high-energy collisions, which can provide valuable information about the structure of matter.

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