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Richard Glocker Building dedicated


Richard Glocker (1890 - 1978), W. C. Röntgen’s last doctoral student, wrote groundbreaking papers both on the biological effect of X-rays and also of high-energy electrons. He established important scientific principles for the therapeutic application of ionizing radiation.

Already in September 2007, two accelerators of the "Elekta Precise" type were put into operation in the Richard Glocker Building. These machines which, in similar or identical configuration might as well be employed in clinics, produce six reference radiation fields for photon radiation and ten reference fields for electron radiation. Thus the energy range applied in practice - 4 MeV to 25 MeV - is fully covered.

In addition, especially small and irregularly shaped radiation fields can be produced by means of a multileaf collimator. These fields constitute irradiation conditions which deviate strongly from the usual reference conditions, but are of great importance for the new clinical irradiation techniques. Investigations of dosimetry under these special irradiation conditions will be a main focus of the work in the Richard Glocker Building.

A linear accelerator, 11 meters long, custom-made for PTB for fundamental dosimetric research, is presently being put into operation by the manufacturer, ACCEL Instruments GmbH, Bergisch-Gladbach, Germany.

On the research accelerator, the electron energy from 0.5 MeV to 50 MeV can be continuously adjusted. Deflection magnets and diaphragms provide a uniquely small energy width. Narrow, expanded and even scanned radiation beams can be produced both with electrons and - a specialty - with photons. Thanks to this flexibility, all imaginable forms of therapy can also be simulated in future, and not only the ones currently in use.

The Richard Glocker Building accommodates four radiation rooms; in up to three rooms, irradiations can be performed simultaneously. The core tasks encompass the providing of standards of the unit "gray" for the water absorbed dose, as well as the testing, improving and developing of dosimeters and dosimetric processes.

Dosimetric research studies the generation and interaction mechanisms of the radiation as a function of fundamental physical quantities such as particle energy and interaction coefficients, as for example the stopping power of electrons in various materials. They will be measured on the research accelerator, and find their way into planning and simulation programmes, which today are indispensable clinical tools.

Figure 1 : Water phantom with ionization chamber for dose measurement in front of the clinical electron accelerator "Elekta Precise". The green laser beams intersect at the measurement point in the water.

Figure 2 : Acceleration path and beamline of the research accelerator. In the foreground, part of the beamline where the electrons reach the final energy of 50 MeV. Blue: quadrupole magnets for beam focusing.