The Diamond machine
The machine is an assembly of components used to produce, confine and maintain a high energy electron beam in a closed orbit for periods of several hours while the electrons produce synchrotron light for a wide variety of experiments.
|
|
Injection system - the electron gun and the LinacThe electrons which orbit around the storage ring and generate 'light' are initially produced by an electron gun. A high voltage cathode is heated under vacuum, giving the electrons in the material sufficient thermal energy to “evaporate” from the surface and escape (thermionic emission). These liberated electrons are then accelerated by earthed anodes, producing a stream of electrons with an energy of ninety thousand electron volts (90keV). A linear accelerator (linac) is used to accelerate the electrons to an extreme relativistic energy of a hundred million electron volts (100 MeV) using RF cavities. The injection system at Diamond is now capable of performing top-up injection: in this mode the electron beam current in the storage ring is kept constant by small, frequent “topping-up” of electrons from the injection system. |
