Dynamitron electron beam accelerators

Larger 3- and 4-m.e.v. Dynamitron electron beam accelerators are likewise available commercially. Service capabilities increase with the m.e.v. level of the electron beam accelerator. A 3.0-m.e.v. Dynamitron electron beam accelerator furnishes radiation capable of penetrating a maximum 370 mils of a unit density material or 185 mils of 2.0-density material other performance capabilities are doubled as well. The overwhelming majority of polyolefin plastic products now being manufactured have section thicknesses which can be penetrated safely even by a 1.5-m.e.v. electron beam accelerator. Two possible exceptions would be printed circuit board and thick-walled pipe. A 3-m.e.v. accelerator could readily meet such requirements. The performance capabilities of the 3-m.e.v. accelerator (12-ma. power supply) are increased not only with respect to maximum depth of penetration but also processing capability, which amounts to 14,000 megarad-pounds per hour at 50% absorption efficiency. 

Several industrial irradiation facilities can now provide both X-ray and electron beam processing for a variety of applications. There are three such facilities in Japan. One of these is equipped with a 5.0 MeV, 150 kW Cockcroft Walton accelerator [14], Another one has a 5.0 MeV, 200 kW Dynamitron accelerator [15], and the third facility has a Rhodotron... 

Irradiations were carried out using a Dynamitron 1.5 MeV electron accelerator, or EBES. In the former case, samples were placed on a conveyor tray and passed underneath the beam. At a velocity of 5.7 cm/sec and a beam current of 1 mA, an absorbed dose of 0.5 Mrads is delivered in a single pass. The dose is thus built up by multiple passes. Alternatively the sample could be held stationary underneath the beam for the requisite period of time necessary to attain a given dose. It will be shown later that the latter approach causes the temperature of the sample to rise significantly during irradiation. 

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