display | more...

One common use of the Bremsstrahlung effect is in high energy physics research, to produce an intense and well-characterized photon beam. Following is a description of a Bremsstrahlung photon tagging system:

  1. Obtain an accelerated electron beam. For modern nuclear photoproduction research you'll want at least several GeV for the beam energy.
  2. Direct the beam onto a thin radiator made of a very heavy metal (such as gold, maybe deposited on carbon foil). Be careful not to overdo it with the radiator; a couple of atoms thick is plenty.
  3. The electrons will scatter off the heavy nuclei. Do not be alarmed, this is normal. Lost kinetic energy will be radiated as Bremsstrahlung photons along the original beam line; ideally very little will be lost in the radiator.
  4. Use a magnetic field to direct the braked electrons onto a bank of scintillation counters. They will naturally strike at different positions depending on their energies.
  5. When a counter fires, you know that an electron of a particular energy just hit it, and that a photon just left the tagger carrying the energy difference to the initial beam.

This system has two main attractions. First, you can figure out (by correcting for time-of-flight) exactly when each photon hit your target and what energy it had. This information will be likely very useful in whatever calculations your research advisor will require of you. Second, it's relatively easy to pump energy into an electron beam. RF LINACs are fairly old technology by now, relatively simple to maintain, and nicely scalable as long as you keep them cold and feed in power.

Log in or register to write something here or to contact authors.