63. For the high temperatures necessary for fusion reactions, using magnetic thermal insulation. Care of the particles of the high temperature zone is prevented by the magnetic field. To determine the current in a gas discharge column of radius 3 cm, required for the electrons having an average speed random motion at 106 K can not be removed from the surface of the column by a distance greater than 0.3 mm.

Detailed solution. Decorated in Microsoft Word 2003. (Target decided to use formula editor)