Heinz Vincke

Radiation protection at CERN

This paper gives a brief overview of the general principles of radiation protection legislation; explains radiological quantities and units, including some basic facts about radioactivity and the biological effects of radiation; and gives an overview of the classification of radiological areas at CERN, radiation fields at high-energy accelerators, and the radiation monitoring system used at CERN. A short section addresses the ALARA approach used at CERN.

Monte Carlo-Based Field Calibration of Radiation Monitors for the Large Hadron Collider at CERN

Abstract Operating a high-energy accelerator like the Large Hadron Collider (LHC) requires a state-of-the-art monitoring system for radiation protection. In the vicinity of the accelerator as well as in the accessible areas behind thick shielding, a unique mixed radiation environment is encountered that consists of different particle types with energies ranging from fractions of electron volt up to several giga-electron-volts. Consequently, the correct assessment of ambient dose equivalent poses a challenging task and requires appropriate field-specific calibration methods, in particular as no adequate calibration sources exist. This circumstance motivated the development of a more accurate field calibration method for the LHC, based on benchmarked FLUKA Monte Carlo simulations. The method of obtaining such field calibration coefficients for IG5 high-pressure ionization chambers is exemplified in a case study for the LHCb experiment. Comparing these factors to calibration source–based values shows over- or underestimation of the actual dose by the source-based coefficient, depending on the location of the monitor.

RADIATION PROTECTION STUDIES FOR THE NEW CERN INJECTOR COMPLEX

Abstract CERN is at present designing a new chain of accelerators to replace the present Proton Synchrotron (PS) complex: a 160-MeV room-temperature linear accelerator (linac) (Linac4) to replace the present 50-MeV linac injector, a 3.5-GeV superconducting proton linac (SPL) to replace the 1.4-GeV PS booster, and a 50-GeV synchrotron to replace the 26-GeV PS. Linac4 has been funded, and civil engineering will start soon, while the SPL is in an advanced stage of design. Beyond injecting into the future 50-GeV PS, the ultimate goal of the SPL is to generate a 4-MW beam to produce intense neutrino beams. The radiation protection design is driven by the latter requirement. This work summarizes the radiation protection studies conducted so far for Linac4. The calculations of the shielding, access maze, ducts for cables, waveguides, and ventilations were performed with the FLUKA Monte Carlo code, complemented by analytical estimates.