External radiation shielding for the protection of electronic devices operating in the flash facility tunnel at desy

Electronic measurement and control instruments incorporating sophisticated micro and macro electronic components operating in the radiation environment of high-energy particle accelerators are prone to radiation induced malfunctions. Many of such devices are now been installed in the containment tunnel of the high-energy electron linac driving the FLASH (free electron laser at Hamburg) facility at DESY. We have developed an efficient concrete material for constructing highly compact shielding walls to protect the electronic devices from the energetic neutrons. This report highlights the Monte Carlo simulation technique we have used for the optimised shielding calculations