Safety aspects for the design and operation of new accelerator facilities 1
a) During the acceleration cycle in the synchrotron, a small fraction of the partially stripped ions will loose electrons due to interaction with the rest gas. These ions leave the orbit and hit the beam tubes, thus inducing radiation. The vacuum specifications for SIS100/200 are such that these beam losses are tolerable. The radiation has also to be kept to a low level in order to avoid the quenching of the superconducting magnets. Nevertheless, the required shielding is quite substantial what made the choice of an underground installation for the SIS100/200, also motivated by ecological considerations, rather obvious.
RADIATION PROBLEMS IN THE DESIGN OF THE LARGE ELECTRON - POSITRON COLLIDER (LEP)
This is a comprehensive review of the radiation problems taken into account in the design studies for the Large Electron-Positron collider (LEP) now under construction at CERN. It provides estimates and calculations of the magnitude of the most important hazards, including those from non-ionizing radiations and magnetic fields as well as from ionizing radiation, and describes the measures to be taken in the design, construction, and operation to limit them. Damage to components is considered as well as the risk to people. More general explanations are given of the physical processes and technical parameters that influence the production and effects of radiation, and a comprehensive bibliography provides access to the basic theories and other discussions of the subject. The report effectively summarizes the findings of the Working Group on LEP radiation problems and parallels the results of analogous studies made for the previous large accelerator. The concluding chapters describe the LEP radiation protection system, which is foreseen to reduce doses far below the legal limits for all those working with the machine or living nearby, and summarize the environmental impact. Costs are also briefly considered.
Investigation of scatter radiation of non-circular X-ray scan trajectories
Modern interventional X-ray devices are highly maneuverable and allow complex 3D imaging trajectories. New scan trajectories enable not only optimized object sampling but also introduce new approaches for dynamic 3D imaging. In this paper, we investigated the scatter radiation of two different scan trajectories. The scatter radiation was sampled by a rail setup with dosimeters at defined positions. After data analysis, contour maps were generated which show for four exemplary heights the scatter radiation distribution. The alternative scan trajectory showed smaller dose exposures at heights correlated to upper torso and head areas of a model physician. Keywords—Image acquisition, alternative scan trajectory, circular tomosynthesis, scatter radiation distribution