Microtron

The microtron is a particle type for electrons can be achieved with the energy up to the order 1 GeV ( giga electron volts). His invention goes back to W. Weksler.

Classic Mikrotron

The original Mikrotron resembles a cyclotron or betatron: It has a single large bending magnet with a homogeneous field. Outside the center of which is a high-frequency acceleration section ( cavity ). Both the magnetic field and the frequency and amplitude of the acceleration voltage are constant, the energy of the particles will therefore, for each passage of the acceleration section by a constant amount to. This also increases the momentum and thus the magnetic stiffness ' of the particles, so that the orbit is longer. Is the speed no longer small compared to the speed of light, will also increase the circulation time. Nevertheless, the particles which acceleration section (', in phase with the high-frequency voltage ) is reached again at the correct time, each time when it is fed so much energy that the round-trip time increases by an integer number of periods of the voltage. One can calculate that the energy gain per revolution must be to the rest energy of the particle is at least equal; therefore the Mikrotronprinzip suitable only for light particles such as electrons (or positrons), but not for protons or even heavier ions. Classical microtron energies of up to about 50 MeV ( mega electron volts ) have been achieved.

Rennbahnmikrotron

The Rennbahnmikrotron is an evolved form of the microtron, named after the shape of their particle trajectory. The magnet is divided here into two parts, each with 180 ° deflection; thus space is gained therebetween to accommodate rather than a Einzelresonators a whole linac ( added additional solenoids for focusing the particle beam ). This allows a greater energy gain per orbit. An example of a Rennbahnmikrotron system is the Mainz Microtron.

Double-sided Microtron

The double-sided microtron is Rennbahnmikrotron containing two linear accelerator on the opposite long sides. The deflection get four 90 ° bending magnets here. This ensures that all orbits lie in the accelerating structures above the other. The short sides between the magnets, the orbits are still displaced in proportion to their energy difference parallel to each other.

When harmonic double sided microtron the frequencies of the accelerator on both sides are not equal, but are in an integer (harmonic) relationship.

Further developments of the double-sided microtron

The number n of the linear accelerator may be increased beyond two; the system then has to be a ring with 2n bending magnets. The Hexatron for example, consists of six 60 ° - bending magnet and three acceleration sections.