Fizika Nizkikh Temperatur: Volume 46, Number 9 (September 2020), p. 1062-1067    ( to contents , go back )

Experimental research of condensation processes occurring under laser ablation in superfluid helium and vacuum

E. B. Gordon, M. I. Kulish1, M. E. Stepanov1, V. I. Matyushenko2, and A. V. Karabulin1,3,4

1Institute of Problems in Chemical Physics of RAS Chernogolovka 142432, Moscow Region, Russia

2Chernogolovka Branch of the N. N. Semenov Federal Research Center for Chemical Physics of RAS Chernogolovka 142432, Moscow Region, Russia

3Joint Institute for High Temperatures of RAS, Moscow 125412, Russia

4National Research Nuclear University MEPhI (Moscow Engineering Physics Institute) Moscow 115409, Russia
E-mail: avkarabulin@gmail.com

Received February 2, 2020, published online July 22, 2020

Abstract

The dynamics of thermal radiation accompanying the condensation of tungsten nanoparticles in superfluid helium and vacuum was studied experimentally in the visible range. It was shown that during the first 100 μs the accompanying thermal energy of process in the case of superfluid helium is considerably higher than in vacuum at comparable temperatures after that it levels up. From a standpoint of the process’ kinetics it is demonstrated that the reasons for this are, on one hand, an increased condensation rate in superfluid helium (due to the concentration of nanoparticles in quantized vortices), and on the other hand, higher efficiency of heating of the condensation products in superfluid helium (due to the prevalence of processes involving particles of similar sizes).

Key words: condensation of tungsten nanoparticles, thermal emission, superfluid helium.

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