ELECTRON RAY IRRADIATION APPARATUS

摘要

PROBLEM TO BE SOLVED: To enhance the efficiency for taking out electrons by keeping an equipotential surface near an opening in a vacuum container from expanding toward an irradiation window. SOLUTION: A slender center electrode 24 having the same potential as the vacuum container 2 is positioned near and along the opening 6 in the vacuum container 2. The center electrode 24 keeps the equipotential surface E near the opening 6 from expanding toward the irradiation window 20, thereby keeping the electrons 18 being accelerated from spreading outwards, and enhancing the efficiency for taking out the electrons 18.