Irradiation equipment

Irradiation arrangement for irradiation of products with a beam of accelerated charged particles and comprising a particle accelerator device, a radiation chamber for reception of products for irradiation and comprising a radiation sector, in which the irradiation of said products takes place, a carrier device for said products to be irradiated for irradiation of said products from at least two sides and controllable means for scanning of said beam of charged particles over the surface of said products alternately from at least two sides, said controllable means comprising a controllable scanning magnet for deflection of said particle beam and redeflection means, wherein said particles are electrons, which at the irradiation in said radiation sector has an energy selected from the range of 1.5 to 2.5 MeV, and wherein:

• said redeflection means comprises, at at least two sides of said radiation sector, positioned redeflection magnets which are substantially circular arch shaped, said scanning magnet deflecting said particle beam so that every portion of said particle beam is incident on one of said redeflection magnets, and so that substantially all portions of said electron beam pass both the deflection in said scanning means and redeflection in said redeflection magnets and are incident to said radiation sector in a direction substantially perpendicular to the direction that the beam axis has immediately before the passage of the beam through said scanning magnet;
• two particle stoppers are arranged in the space between respective pole pieces of said redeflection magnets, which particle stoppers are constituted of water cooled copper or aluminum;
• the electron beam incident from said scanning magnet is deflected towards said radiation sector at the same time as the electron radiation passing said radiation sector without being absorbed, is deflected towards the particle stoppers;
• said scanning magnet deflects said electron beam by an angle, the absolute value of which falls within the range of 15-45 degrees;
• each product under irradiation is positioned in said radiation sector with the normal of the surface to be irradiated directed in a direction substantially perpendicular to the direction that the radiation axis has immediately before the passage of the beam through said scanning magnet;
• the controllable means also comprises a focusing electron lens, which is controllable synchronously with said controllable scanning magnet to give rise to a constant beam size in said radiation sector,
• said carrier device comprises a conveyor belt made of two webs of metal wire net, which transports said products through said radiation sector, fixes said products to said transport device during transport through the irradiation arrangement by jamming the products between said webs and is connected with actuating means, whereby said webs are driven, separately, but in co-operation with each other, by respective actuating means in a closed loop, said loops are connected to each other along at least the distance the products are transported through the irradiation arrangement, and
• a predetermined radiation dose is achieved by controlling the actuation velocity of said conveyor belt from a position outside of the radiation space and is dependent on the scanning width of the controllable means and the beam power of said particle acceleration device.

Method for irradiating products in a radiation chamber with charged particles from a particle acceleration device by using a controllable means for scanning the beam of charged particles over the surface of said products alternately from at least two sides, whereby said method comprises the steps of:

• positioning said products to be irradiated in a radiation sector;
• scanning said beam of charged particles over the surface of said products alternately from at least two sides;
• scanning said beam by controlling the deflection from a scanning magnet to at least one range of deflection angles and use of redeflection from at least two redeflection magnets so that every portion of said particle beam is deflected by said scanning magnet and redeflected by one of said redeflection magnets;
• and
• the positioning of each product in said radiation sector is performed in such a way that the normal of the surface to be irradiated is directed in a direction substantially different from the direction that the beam axis has immediately before the passage of the beam through said scanning magnet.

System for production of sterile products comprising an irradiation arrangement for irradiation of products with a beam of accelerated charged particles, which irradiation arrangement comprises a particle accelerator device, a radiation chamber for reception of products for irradiation and comprising a radiation sector, in which the irradiation of said products takes place, a carrier device for presenting said products for irradiation from at least two sides and controllable means for scanning said beam of charged particles over the surface of said products alternately from at least two sides, said controllable means comprising:

• redeflection means comprising redeflection magnets positioned at at least two sides of said radiation sector;
• a controllable scanning magnet disposed to deflect respective portions of said particle beam so that each of said particle beam portions is incidental toward one of said redeflection magnets;
• and
• each of said redeflection magnets has a geometrical shape which by its magnetic field deflects each incident particle beam portion from said scanning magnet towards said radiation sector in a direction substantially perpendicular to that direction the beam axis has immediately before the passage of the beam through said scanning magnet.