Parallel plate electron multiplier with ion feedback suppression
View Patent ↗An embodiment of the invention is an electron multiplier including a first plate having an electron emissive first interior surface. A second plate has an electron emissive second interior surface. A voltage source is connected across the first plate and the second plate. A collector generates a signal responsive to electron multiplication by the first plate and the second plate. The first interior surface and the second interior surface are parallel and are non-planar.
1. A electron multiplier comprising:
a first plate having a first interior surface, said first interior surface being electron emissive;
a second plate having a second interior surface, said second interior surface being electron emissive, the second plate being separate from the first plate;
the first plate and the second plate are spaced apart to define a channel, the channel having an input end receiving electrons;
a voltage source connected across said first plate and said second plate;
a collector at an output end of the channel, the collector generating a signal responsive to electron multiplication by said first plate and said second plate;
wherein said first interior surface and said second interior surface are parallel and are non-planar, the channel providing a non-linear path from the input end to the output end.
2. The electron multiplier of claim 1 wherein:
said first interior surface and said second interior surface correspond to one period of a waveform.
3. The electron multiplier of claim 1 wherein:
said first interior surface and said second interior surface correspond to two periods of a waveform.
4. The electron multiplier of claim 1 wherein:
said first plate and said second plate correspond to sections of concentric cylinders.
5. The electron multiplier of claim 1 wherein:
said first plate and said second plate are made from reduced lead oxide glass or reduced bismuth oxide glass.
6. The electron multiplier of claim 1 wherein:
said first plate and said second plate are formed in multiple layers.
7. The electron multiplier of claim 6 wherein:
one of said layers is a support layer.
8. The electron multiplier of claim 7 wherein:
said support layer is made from Al 2 O 3 , AlN, Si, SiO 2 glass, Si 3 N 4 , or SiC.
9. The electron multiplier of claim 6 wherein:
one of said layers is a resistive layer.
10. The electron multiplier of claim 9 wherein:
said resistive layer is made from Si, C, Ge, or Si 3 N 4 .
11. The electron multiplier of claim 10 wherein:
said resistive layer is chemical vapor deposited.
12. The electron multiplier of claim 6 wherein:
one of said layers is an electron emissive layer.
13. The electron multiplier of claim 12 wherein:
said electron emissive layer is made from diamond films, Al 2 O 3 , Si 3 N 4 , SiO 2 , MgO, or BN.
14. The electron multiplier of claim 12 wherein:
said electron emissive layer is chemical vapor deposited.
15. The electron multiplier of claim 1 wherein:
the input end of the channel has an increased dimension with respect to the remainder of the channel.