Ionization cell for a mass spectrometer, and corresponding leak detector

An ionization cell, for a mass spectrometer (2), comprising:

• an ionization cage (10) comprising first and second electron entrance slits (11, 26) in opposite sides thereof, and having an exit slit (15) for the passage of ionized particles (14a, 14b, 14c);
• a working first filament (13), placed facing said first electron entrance slit (11) and operational when powered to produce an electron beam (12) which is injected through said first electron entrance slit into a region inside said ionization cage maintained at a given pressure level;
• and
• a backup second filament (22), placed facing said second electron entrance slit (26) and operational when powered to produce an electron beam which is injected through said second entrance slit into an adjacent region inside said ionization cage maintained at said given pressure level, said second filament being powered in the event of failure of the working first filament (13),
• said second electron entrance slit (26) being placed outside of a frontal region F facing said first electron entrance slit (11).

An ionization cell, for a mass spectrometer (2), comprising:

• an ionization cage (10) comprising first and second electron entrance slits (11, 26) in opposite sides thereof and both in communication with a common region of an interior of said cage having a given pressure level, and having an exit slit (15) for the passage of ionized particles (14a, 14b, 14c);
• a working first filament (13), placed facing said first electron entrance slit (11), intended to be powered so as to produce an electron beam (12);
• and
• a backup second filament (22), placed facing said second electron entrance slit (26), intended to be powered, in the event of failure of the working first filament (13), so as to produce the electron beam,
• said second electron entrance slit (26) being placed outside of a frontal region F facing said first electron entrance slit (11).