Removable Ion Source Capable Of Axial Or Cross Beam Ionization

Abstract

An ion source including an ionization assembly, first and second electron sources, and a magnet assembly. The ionization assembly includes an ionization chamber and at least one ion lens. The ionization assembly has a primary axis defined by the direction of an ion beam exiting the ionization assembly and the ionization chamber and the at least one ion lens are arranged along the primary axis. The first electron source is aligned along the primary axis of the ionization assembly and is configured to provide an electron beam parallel to the primary axis. The second electron source is adjacent to the ionization assembly and is configured to provide an electron beam orthogonal to the primary axis. The magnet assembly includes a magnet. The magnet assembly is movable between a first position in which the magnet is aligned with the first electron source and a second position in which the magnet is aligned with the second electron source.

1 . An ion source comprising:
 an ionization assembly including an ionization chamber and at least one ion lens, the removable ionization assembly having a primary axis defined by the direction of an ion beam exiting the ionization assembly, the ionization chamber and the at least one ion lens arranged along the primary axis; and   a first electron source aligned along the primary axis of the ionization assembly and configured to provide an electron beam parallel to the primary axis;   a second electron source adjacent to the ionization assembly and configured to provide an electron beam orthogonal to the primary axis;   a magnet assembly including a magnet; the magnet assembly movable between a first position in which the magnet is aligned with the first electron source and a second position in which the magnet is aligned with the second electron source.   
     
     
         2 . The ion source of  claim 1 , wherein the ion source operates in an electron ionization mode when the magnet assembly is in the first position. 
     
     
         3 . The ion source of  claim 1 , wherein the ion source operates in a chemical ionization mode when the magnet assembly is in the second position. 
     
     
         4 . The ion source of  claim 1 , wherein at least one of the first electron source and the second electron source includes a thermionic filament. 
     
     
         5 . The ion source of  claim 1 , wherein at least one of the first electron source and the second electron source includes a field emitter. 
     
     
         6 . The ion source of  claim 1 , wherein the ionization assembly is removable when the magnet assembly is in the second position. 
     
     
         7 . The ion source of  claim 1 , wherein a direct insertion probe (DIP) and direct exposure probe (DEP) can be inserted into the ionization assembly when the magnet assembly is in the second position. 
     
     
         8 . The ion source of  claim 1 , wherein the magnet is a temperature compensated samarium cobalt magnet. 
     
     
         9 . The ion source of  claim 1 , wherein the magnet assembly includes a second magnet. 
     
     
         10 . The ion source of  claim 1 , wherein the magnet assembly is thermally coupled to a portion of the vacuum chamber, the portion of the vacuum chamber acting as a heat sink. 
     
     
         11 .- 19 . (canceled) 
     
     
         20 . A method of operating an ion source in two modes, comprising:
 using a first electron source to ionize a first sample within an ionization assembly of the ion source, the ionization assembly having a primary axis defined by the direction of an ion beam exiting the ionization assembly, the ionization chamber and at least one ion lens arranged along the primary axis, a magnet assembly, including one or more magnets, positioned to align at least one of the one or more magnets with the first electron source, the first electron source aligned along the primary axis of the ionization assembly and configured to provide an electron beam parallel to the primary axis;   moving the magnet assembly to a second position in which at least one of the one or more magnets is aligned with a second electron source adjacent to the ionization assembly, the second electron source configured to provide an electron beam orthogonal to the primary axis;   using the second electron source to ionize a second sample within an ionization assembly.   
     
     
         21 . The method of  claim 20 , wherein the ion source operates in an electron ionization mode when the at least one of the one or more magnets is aligned with the first electron source. 
     
     
         22 . The method of  claim 20 , wherein the ion source operates in a chemical ionization mode when the at least one of the one or more magnets is aligned with the second electron source. 
     
     
         23 . The method of  claim 20 , further comprising inserting a direct insertion probe (DIP) and direct exposure probe (DEP) into the ionization assembly when the magnet assembly is in the second position. 
     
     
         24 . A method of removing an ionization assembly from an ion source, comprising:
 moving a magnet assembly including a magnet from a first position in which the magnet is aligned with an electron source to a second position in which the magnet does not obstruct removal of the ionization assembly, the ionization assembly having a primary axis defined by the direction of an ion beam exiting the ionization assembly, the ionization chamber and at least one ion lens arranged along the primary axis, the electron source aligned along the primary axis of the ionization assembly and configured to provide an electron beam parallel to the primary axis; and   removing the ionization assembly from the ion source.   
     
     
         25 . The method of  claim 24 , further comprising inserting the ionization assembly or a replacement ionization assembly into the ion source; and moving the magnet assembly from the second position to the first position. 
     
     
         26 . The method of  claim 24 , further comprising using electron source to ionize a sample when the magnet is in the first position.