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Polymers/Electron beam

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U+269B.svg Subject classification: this is a science resource.

Electron Beam generators are used to modify surface and bulk properties of polymer films by grafting or crosslinking, but also for initiating polymerisation and curing.

caption EB

The Energy Sciences International Electron Beam at the Laboratory of Polymer Technology at Åbo Akademi University

PrincipleEdit

Electrons are generated with a wolfram (tungsten) filament in vacuum. The electrons are accelerated in an electric field towards a window allowing them to escape from the vacuum chamber. Samples underneath the beam are subjected to the electrons, which are creating cascades of new, lower energy electrons, when colliding in the material. The penetration depth is a function of material density and acceleration voltage.

Electron beam instruments are often classified as high energy (5.0 - 10.0 MeV), medium energy (0.5 - 5.0 MeV), and low energy accelerators (0.1 - 0.5 MeV). The depicted instrument above can accelerate electrons up to 0.175 MeV.

DosesEdit

The energy absorption in a material is expressed in the SI-unit Gray (Gy) which amounts to 1J (Joule) of energy absorbed in 1 kg of matter. The dose rate is expressed as Gy/s.

Penetration DepthEdit

Application ExampleEdit

--Kalle 05:59, 27 October 2006 (UTC)