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The linear accelerators available are two clinical accelerators and a research accelerator with two irradiation set-ups. So a total number of four iradiation set-ups are available for investigations in the field of clinical dosimetry or dosimetric fundamental research.

The two clinical accelerators of type Elekta Precise Treatment System^TM can generate high-energy photon radiation with nominal accelerating voltages between 4 MV and 25 MV and electron radiation with energies between 4 MeV and 22 MeV. One accelerator is equipped with a multileaf collimator. Using this accelerator investigations in very small or irregularly shaped beams, as they are used for instance in Intensity Modulated Radiation Therapy (IMRT), can be done. Such radiation fields, which deviate significantly from the standardized reference fields, are increasingly used in the framework of new irradiation modalities; the importance of dosimetry in such fields is therefore increasing.

The linear accelerator (11 m in length) for dosimetric fundamental research has been custom-built for PTB. The energy of the accelerated electrons can be varied continuously from 0.5 MeV to 50 MeV; the electron beam power is up to 1 kW. A total of two irradiation set-ups are available which allow irradiation with electron energies in the range 0.5 MeV to 10 MeV and 6 MeV to 50 MeV, respectively.

The properties of the electron beam, as for instance the beam position, beam profile, spectral electron fluence or the beam current can be measured. Therefore, in the field of fundamental research, radiation effects can be studied as a function of these fundamental physical quantities of electrons.