Development of a front-end electronics for an innovative monitor chamber for high-intensity charged particle beams

A multi-gap ionization monitor chamber has been developed by INFN and Torino University, for monitoring of high intensity pulsed charged particle beams. The read-out of the chamber is based on a 64-channel ASIC, designed in CMOS 0.35μm technology which features for each channel an independent current-to-frequency converter followed by a synchronous counter. The chip was designed for connecting each channel to a different detector element. However, high beam intensities may lead to an input current above the saturation level of a single channel. A novel readout has been tested where all the input channels of the chip have been connected in parallel to the same detector element allowing to reach 64-times higher input current with only a modest deterioration of the resolution. Results will be presented in terms of linearity and noise, and will be compared to a simulation where the chip is modeled as a set of independent and uncorrelated channels.