The multi-energy electron LINAC was an experimental device developed for irradiation metrology, the vacuum system is a main part of the device to maintain a low pressure. The accelerator tube is made of copper and the vacuum chamber is almost entirely made of stainless steel. The multi-energy electron LINAC was an experimental device developed for irradiation metrology, the vacuum system is a main part of the device to maintain a low pressure. The accelerator tube is made of copper and the vacuum chamber is almost entirely made of stainless steel.