The development of low currents measuring channel necessary to ensure the operation of the experimental complex based on a linear electron accelerator with energy of 30 MeV at IHEPNP NSC KIPT for fundamental and applied research on the interaction of high-energy electrons with amorphous and single-crystal structures is described. The channel makes it possible to measure currents of the order of 0.1 nA and less, with an accuracy better than 0.1 %, and is connected to an upper-level computer via the USB interface.

The control unit for the goniometer has been developed and manufactured. The unit includes four independent programmable stepper motor control channels, three logical channels for analyzing the state of limit switches and a power supply. Powerful field-effect transistors of the company International Rectifier are used as controlled power switches. To generate output signals and communicate with a computer, an ATmega328 microprocessor is used in each control channel. This channel design allows you to control almost any type of stepper motors, you only need to replace the control program. The software is written using the WinAVR package which has a General Public License. Data transfer between the computer and the unit is carried out via the USB interface.