A cathode device includes an emitter tip for generating electrons. An elongate heater is included having proximal and distal ends. The emitter tip can be located at the distal end of the heater. Two spaced apart legs can extend away from the distal end of the heater, terminating at the proximal end and forming an elongate slot therebetween. Two electrical contacts can compressively engage respective opposite outer surfaces of the two legs at the proximal end of the heater to mechanically secure and electrically connect the two legs of the heater to respective electrical contacts at a junction that is at a location spaced away from the emitter tip to keep the junction cooler.

A cathode device includes an emitter tip for generating electrons. An elongate heater is included having proximal and distal ends. The emitter tip can be located at the distal end of the heater. Two spaced apart legs can extend away from the distal end of the heater, terminating at the proximal end and forming an elongate slot therebetween. Two electrical contacts can compressively engage respective opposite outer surfaces of the two legs at the proximal end of the heater to mechanically secure and electrically connect the two legs of the heater to respective electrical contacts at a junction that is at a location spaced away from the emitter tip to keep the junction cooler.

An electron emission element (20) includes a first electrode (30a) and a second electrode (40) which are arranged facing each other, an intermediate layer (50) that is provided between the first electrode (30a) and the second electrode (40), and an insulating layer (60) that is formed with a thickness d1 on a substrate (30). A level difference between the insulating layer (60) and the first electrode (30a) is smaller than the thickness d1 of the insulating layer (60).

A method includes assessing a plurality of Titanium plates to determine a grain size for each plate and removing all Titanium plates with an average grain size that is larger than a threshold size from the plurality of Titanium plates. One of the Titanium plates remaining in the plurality of Titanium plates after the removing step is then used to form a cathode for an ion pump.

A method includes assessing a plurality of Titanium plates to determine a grain size for each plate and removing all Titanium plates with an average grain size that is larger than a threshold size from the plurality of Titanium plates. One of the Titanium plates remaining in the plurality of Titanium plates after the removing step is then used to form a cathode for an ion pump.

In order to provide a thermionic emission filament capable of ensuring a long life and improving an analysis accuracy of a mass spectrometer using the thermionic emission filament, in the thermionic emission filament including a core member through which electric current flows and an electron emitting layer which is formed so as to cover a surface of the core member, the electron emitting layer is configured to have denseness for substantial gas-tight integrity.

In order to provide a thermionic emission filament capable of ensuring a long life and improving an analysis accuracy of a mass spectrometer using the thermionic emission filament, in the thermionic emission filament including a core member through which electric current flows and an electron emitting layer which is formed so as to cover a surface of the core member, the electron emitting layer is configured to have denseness for substantial gas-tight integrity.

In order to provide a thermionic emission filament capable of ensuring a long life and improving an analysis accuracy of a mass spectrometer using the thermionic emission filament, in the thermionic emission filament including a core member through which electric current flows and an electron emitting layer which is formed so as to cover a surface of the core member, the electron emitting layer is configured to have denseness for substantial gas-tight integrity.

In order to provide a thermionic emission filament capable of ensuring a long life and improving an analysis accuracy of a mass spectrometer using the thermionic emission filament, in the thermionic emission filament including a core member through which electric current flows and an electron emitting layer which is formed so as to cover a surface of the core member, the electron emitting layer is configured to have denseness for substantial gas-tight integrity.

Aspects include a method for treating a polycrystalline material, the method comprising: exposing a surface of the polycrystalline material to a plasma thereby changing the surface of the polycrystalline material from being characterized by a starting condition to being characterized by a treated condition; wherein: the surface comprises a plurality of crystallites each having the composition MB.sub.6, M being a metal element; the plasma comprises ions, the ions being characterized by an average ion flux selected from the range of 1.5 to 100 A/cm.sup.2 and an average ion energy that is less than a sputtering threshold energy; the starting condition of the surface is characterized by a first average work function and the treated condition of the surface is characterized by a second average work function; and the second average work function is less than the first average work function.