Residual gas sensor utilizing a miniature quadrupole array

A gas sensor for measuring the presence of gas ions, comprising:

• a base;
• a plurality of rods arranged in parallel and spaced apart from each other to form an array wherein said rods are fixedly positioned in said base, said base providing cantilevered support for said rods at one end only;
• a first electrical lens to cause gas ions to travel in at least one channel formed by said array of said rods;
• and
• a collector mounted within said array, having a surface positioned within said at least one channel, that outputs an electrical signal responsive to the quantity of gas ions traveling in said channels contacting said surface, wherein said base comprises a glass seal formed by reflowing a pre-formed glass bead having appropriately positioned holes for said plurality of rods and said plurality of pins.

A residual gas sensor for use in a low pressure chamber comprising:

• a plurality of rods arranged in parallel and spaced apart from each other to form an array wherein said rods are fixedly positioned within a glass seal to maintain said array, said glass seal further providing a seal to prevent escape of gases from said low pressure chamber;
• means for ionizing gas molecules present within said low pressure chamber;
• means for inducing ionized gas molecules to travel in at least one of a plurality of channels formed by said array of said rods;
• means for selectively tuning an oscillating electric field within said plurality of channels;
• and
• means for detecting ionized gas molecules having traveled a pre-selected distance within said channel.

A gas sensor for measuring the presence of gas ions, comprising:

• a base;
• a plurality of rods fixedly positioned at one end in said base, each of said rods having a length, said rods arranged in parallel and spaced apart from each other to form an array of quadrupoles;
• an electrical lens to cause gas ions to travel in a plurality of channels formed by said array of said rods, each channel corresponding to one quadrupole in said array of quadrupoles;
• and
• a collector mounted within said array, said collector having a surface portion positioned within each of said channels, said collector outputting an electrical signal responsive to the quantity of gas ions traveling in said channels and contacting said surface portions,
• wherein the length of each of said rods is chosen to be sufficiently short that said gas sensor can operate at pressures as high as 1.5.times.10.sup.-2 torr.