It is to shield the inner chamber for high radiation emission to environment during nuclear researches.

• One main chamber made of 5 mm thick steel sheet
• One main chamber outer envelope made of 5 mm thick steel sheet
• One sliding cover lid made of 5 mm and 10 mm thick steel sheets
• All the parallel steel sheets walls filled with lead tablets
• Inner surface of main chamber and cover lid are coated with 1.5 mm copper plate