Buncher design and optimization for industrial RF electron linacs

The electron linacs with output energy up to 10 MeV are very popular for industrial applications like food irradiation, sterilization of medical products, coloration of diamonds etc. One of the applications is using such linac as an X-ray source for cargo-inspection system, where high energy and intensity of γ-quanta are necessary to obtain clear images of the inspected items. Hence, RF Electron accelerators that provide a fairly high capture coefficient, narrow energy spectrum and reasonably high accelerating gradient are of particular interest. In the interest of the above, S-band 2856 MHz, π/2 mode standing wave bi-periodic RF structures for 6-10 MeV linacs have been designed, developed, and beam tested at Electron Beam Centre, BARC. In this paper, the study of new buncher with input electron beam energy of ∼ 25 keV with optimum beam transmission, energy spread and RF studies is described. Because of the low injection energy, the size of the electron gun and handling of HV power supplies will be reduced. Already the buncher has been designed, manufactured and rf tested. (author)