SYSTEM FOR MEASURING IONIZATION CHAMBER CURRENTS IN EXPERIMENTS WITH SYNCHROTRON RADIATION
A device for measuring ionization chamber currents in the range from 5·10 -15 to 3·10 -6 A is presented. The intrinsic noise is analyzed and it shown that its root-mean-square value does not exceed the estimated minimum of 5 fA. The device is designed for experiments with synchrotron radiation, but it can also be used in applications requiring low-current measurements.