Observation of the strong anomalous absorption of the X-mode pump in a plasma filament due to the two-plasmon decayA. B. Altukhov, V. I. Arkhipenko, A. D. Gurchenko, E. Z. Gusakov, A. Yu. Popov, L. V. Simonchik and M. S. UsachonakEPL, 126 1 (2019) 15002DOI: https://doi.org/10.1209/0295-5075/126/15002