33.3 Accelerators Create Matter from Energy

Which of the below was the first hint that conservation of mass and conservation of energy might need to be combined into one concept?

1. The Van de Graaff generator.
2. New particles showing up in accelerators.
3. Yukawa's theory.
4. They were always related.

Use the information in the reference to answer the following questions.

Taking only energy and mass into consideration, what is the minimum amount of kinetic energy a K^- must have when colliding with a stationary proton to produce an Ω?

1. 240.5 MeV
2. 120.0 MeV
3. 15.5 MeV
4. 57.6 GeV

A π⁺ and a π^- are moving toward each other extremely slowly. When they collide, two π⁰ are produced. How fast are they going? (Ignore relativistic effects.)

1. Barely moving
2. 1.0×10⁷ m/s
3. 2.0×10⁷ m/s
4. 7.8×10⁷ m/s

At full energy, protons in the 2.00-km-diameter Fermilab synchrotron travel at nearly the speed of light, since their energy is about 1000 times their rest mass energy.

(a) How long does it take for a proton to complete one trip around?

(b) How many times per second will it pass through the target area?

What length track does a $\pi^{+ }$ traveling at 0.100 c leave in a bubble chamber if it is created there and lives for $2 . \text{60} \times \text{10}^{- 8} \text{s}$? (Those moving faster or living longer may escape the detector before decaying.)

Because of energy loss due to synchrotron radiation in the LHC at CERN, only 5.00 MeV is added to the energy of each proton during each revolution around the main ring. How many revolutions are needed to produce 7.00-TeV (7000 GeV) protons, if they are injected with an initial energy of 8.00 GeV?

When an electron and positron collide at the SLAC facility, they each have 50.0 GeV kinetic energies. What is the total collision energy available, taking into account the annihilation energy? Note that the annihilation energy is insignificant, because the electrons are highly relativistic.