International Topical Meeting on Nuclear Research Applications and Utilization of Accelerators

4-8 May 2009, Vienna

Electron Beam Processing — What are the Limits

A.G. Chmielewsky

Institute of Nuclear Chemistry and Technology, Warsaw, Poland

Corresponding Author: A.Chmielewski@ichtj.waw.pl

Radiation emitted from electron accelerators or γ sources is widely applied in the industry. Up to 200 big γ irradiators and up to 2000 electron accelerators are used for radiation processing. The radiation sources are installed in service centers or are incorporated as a unit in the technological line. The biggest application of the process concerns sterilization and polymer cross-linking. Other still being a challenge is application of the technology in food irradiation. The biggest applications in line regarding the power of machines used type concern environmental protection. The advantage of electron accelerators over γ sources is due to the high dose rate what shortens the processing time. An electron accelerator of the power 15 kW regarding delivered dose is equivalent to 1 MCi of the Co-60. Electron accelerators of the power 150 kW and the energy 10 MeV are available on the market The present situation concerning difficulties in the cobalt delivery due to transport restrictions will promote accelerator applications as a radiation source. However, the penetration range of the γ rays is much larger than those of electron beam, of accepted processing energy up
to elements activation limits. The application of e/X conversion is a technical feasibility, however due to the low conversion efficiency this is a first limit of this technique. Other limit concerns reliability of accelerators for in line applications, the 8500 hours continuous operation in the year is required. Therefore, these above mentioned physical requirements are the technical limits. Other limits are created by the presence of other technologies on the market. These technologies are in some cases presented as a cheaper from the operational and investment costs point of view and they are simpler regarding safety and operational conditions. In many cases, they base on not very well specified economical and technical parameters to be compared. All these factors are discussed in the paper.

Full text paper