Physics Stack Exchange is a question and answer site for active researchers, academics and students of physics. Join them; it only takes a minute:

Sign up
Here's how it works:
  1. Anybody can ask a question
  2. Anybody can answer
  3. The best answers are voted up and rise to the top

Are any photomultipliers used in any of LHC detectors? Or are only semiconductor devices used?

If yes, then where?

share|cite|improve this question
You should be aware that PMTs come in a variety of sizes and form factors, and that modern ones can be very small indeed and come packaged in groups. One experiment I'm on uses a 64PMTs-in-one-module device. – dmckee May 25 '12 at 14:35
up vote 5 down vote accepted

Yes, photomultipliers are in use in calorimeters which use Cerenkov light to detect the passage of particles. An example is in this preprint of the Castor detector at CMS in LHC.

Charged particles penetrating the CASTOR calorimeter will generate showers in the tungsten absorber plates. These particle showers are sampled by using the Cherenkov effect. Quartz plates are the active medium to generate the Cherenkov light. They are in the form of thin plates inclined by 45± with respect to the beam axis in order to maximize the Cherenkov light. Cherenkov light generated by the charged particles carries the particle-related information. In the CASTOR calorimeter the R5380Q PMT series of Hamamatsu will be used to read out the Cherenkov light (see Table 1 for CASTOR PMT specifications). The Cherenkov light produced in the quartz plates will be transmitted to the PMTs by the mediation of the air filled light guides.

If you go to the document search page of CERN and search for photomultipliers and CMS you will find many references, though most behind paywalls. This is how I got the preprint above.

share|cite|improve this answer

Your Answer


By posting your answer, you agree to the privacy policy and terms of service.

Not the answer you're looking for? Browse other questions tagged or ask your own question.