Credit: TPU microtron The scientists of Tomsk Polytechnic University jointly with the colleagues from Keysight company have conducted an experiment with an electron beam at the TPU microtron to study a super-radiant regime that occurs when radiation is generated by a train of electron bunches. The research findings obtained by a high-precision measurement of a spectral line width proved that about 8,000 electron bunches in a super-radiant regime form monochromatic Cherenkov radiation. This experiment was conducted for the first time. The fundamental research findings are published in the Scientific Reports academic journal (IF: 4.120, Q1) and can be used for further research on the new sources of radiation in the terahertz range.