Particle Countin' - Test What You Learned

• Question 1: Which object seems to have the most particles coming out?

  Fiestaware Plate

  Watch

• Question 2: Does the Geiger counter count more particles when objects are close by or when they are far away? Explain your answer in the box below.

  Close by

  Far away

• Question 3: Which shield does the best job stopping the particles?

  Wood

  Lead

  No Shield

• Question 4: Why do you think the Geiger counter can still count particles even though you put a shield in the way?

• Question 5: Why do you still hear some clicks on the Geiger Counter when you have no source?

• Question 6: Physicists at Fermilab build their detectors with layers of different materials to trap the particles. These type of detectors are called Calorimeters. If you were going to trap all these particles with a layer of material, which would you use?

  Wood

  Lead

Double Your Bucks by reading about detectors and answering the question correctly:

Calorimetric ("energy-measuring") detectors absorb the energy of a particle and convert it into light which can be observed by light-sensitive detectors. The amount of light observed measures the energy of the particle. Absorbing high-energy particles requires a lot of material, typically many feet of steel or lead. The calorimeter surrounds the point of interaction in a collider detector.
	In calorimeters different particles travel different distances before being absorbed. Photons and electrons lose energy very quickly and stop in the first layers of a calorimeter. Muons, by contrast, can pass through many feet of steel before losing their energy. Jets from quarks have an intermediate range. Physicists use the distance a particle travels in a calorimeter to identify the particle.

• Question 7: In which layer would photons be trapped?

  Tracking

  Electromagnetic

  Hadron

  Muon