The main direction of scientific activity is the study of methods of compression of electric energy and its conversion into powerful fluxes of charged particles and x-ray radiation. He is the head of the department of high energy densities at HCE SB RAS.

Under his leadership, a number of unique terawatt multipurpose pulse generators were developed. Based on them, a number of pioneering studies were carried out, as a result of which the effective generation of soft X-rays and multimega-Gaussian magnetic fields in nanosecond Z-pinches was demonstrated for the first time, pulsed pressures of tens of megabars were obtained during electrodynamic compression of condensed matter, record results on ultra-hard X-ray and gamma radiation were obtained when braking terawatt electron beams, which have found practical application. The works of N. A. Ratakhin are widely known in Russia and abroad.

For the first time, with the participation of employees of the A.F. Ioffe Physics and Technology Institute, he performed direct measurements of the characteristics of (ne, Te) plasma (by laser scattering) in high-current diodes with explosive electron emission.

Under his leadership, a number of original nanosecond mega-ampere installations (SNOP-3, SGM, MIG) of the terawatt power range, for a number of parameters having no analogues, was developed, a unique MIG setup was created, in which practically all known methods of generating powerful pulses (electric explosive and plasma choppers of current, the use of a linear pulse transformer, water-forming line technology, etc.) are successfully combined, which made it possible to realize a wide range of electric pulses with a high coefficient. He made a significant contribution to the creation, testing and development of mass production of special equipment. In 2001, as part of the team of authors, he was awarded the First Prize of the Joint Institute for Nuclear Research (Dubna) for his work “Investigation of reactions between light nuclei in the field of ultra-low energies using liner plasma”.