Design and development of processing electronics for multi-strip collector array to measure beam profile of industrial linac

Industrial electron Linacs, capable of delivering maximum beam energy of 10 MeV (beam current: 300 mA, pulse width: 10 µs, pulse repetition rate: 1-300 Hz) are being developed by RRCAT. For characterization of electron beam of industrial Linac, a multi-strip collector array has been developed indigenously which measures its beam parameters such as beam shape, size and profile. It consists of a one-dimensional array of individual Cu strips (16-strips made of copper) which are isolated from each other by means of kapton film. When beam falls on the collectors, pulse current signals are generated proportional to the beam portion falling on them. These current signals are processed and measured to estimate the beam profile of electron beam. In this paper design and development of 16-Channel switched integrator based processing electronics for multi-strip collector array is presented. The developed processing electronics can measure current signal in the range of 0.3 mA to 300 mA with accuracy better than ±1% in mA range. It has been beam tested with the industrial electron Linac, operating at nominal beam energy 7.5 MeV and repetition rate 1 Hz. The initial beam profile measurement results using developed electronics are presented in this paper with different steering and focusing strengths. The beam size of the electron Linac was also observed using radiochromic film. The measured values of beam size using radiochromic film and developed processing electronics closely match. This verifies the beam profile measurement using developed processing electronics of multi-strip collector array. (author)