First observations of tongue deformation of plasma based upon the Artsimovich Prediction

At the National Institutes of Natural Sciences National Institute for Fusion Science researchers, in collaboration with Kyushu University, observed for the first time in the world a deformation called the 'tongue deformation' occurring locally in a Large Helical Device (LHD) plasma. This deformation was predicted by Lev Artsimovich in the late 1960s. Since then it has not been observed experimentally, becoming a riddle in plasma physics not solved for 50 years.