MOLECULAR BEAM INTENSITY MONITOR

摘要

PURPOSE:To eliminate influence due to re-evaporation of an adhered substance and to measure molecular beam intensity accurately by providing a heating means at a part where heat from the filament of an ionization vacuum meter directly arrives and then re-evaporating the substance which is adhered to that part in advance. CONSTITUTION:A heater 11 is installed in a wall part 22 of an enclosure 2 where an ionization vacuum meter 3 is laid out inside. It is desirable to use a non-induction coil for the heater 16 so that another measurement may not be affected. Molecular beams coming from a cell pass through an opening 21 of the enclosure 2 and then reaches the vacuum meter 3. However, since the molecular beams have a certain degree of spread, a thin film (substance) is adhered also to each part of the enclosure 2 and an adjacent manipulator 6. The heater 16 heats a part at which the heat of a filament 31 of the vacuum meter 3 directly arrives, namely the surface of the enclosure 2 or the adjacent manipulator 6 to reevaporate the thin film, thus eliminating the influence for the indication value of the vacuum meter 3.