Partially grounded depressed collector
View Patent ↗A depressed beam collector and an RF source comprising a depressed beam collector. The RF source may include, e.g., a multi-beam klystron, a single beam klystron, or other RF sources having an electron gun. The beam collector collects spent electrons from the electron gun and comprises a grounded portion configured to collect a portion of electrons entering the collector and a biased portion configured to collect another portion of the electrons entering the collector and having a depressed energy.
1. A depressed beam collector comprising:
a grounded portion configured to collect a portion of electrons entering the collector;
a biased portion configured to collect another portion of the electrons entering the collector and having a depressed energy, wherein the grounded portion and the biased portion each form a portion of a wall of the depressed beam collector;
a high voltage gap comprising a spacing in the wall between the grounded portion and the biased portion; and
a magnetic lens at least partially surrounding the high voltage gap.
2. The depressed beam collector of claim 1 , wherein the beam collector comprises a plurality of channels, each channel corresponding to one of a plurality of electron beams.
3. The depressed beam collector of claim 1 , wherein the biased portion is coupled to a depressed power supply at a collector voltage.
4. The depressed beam collector of claim 1 , wherein the magnetic lens is configured to suppress reflection of a spent beam functioning in concert with the space charge distribution.
5. The depressed beam collector of claim 4 , wherein the magnetic lens is configured to create a magnetic field for guiding a spent beam to penetrate the grounded portion and then to disperse.
6. The depressed beam collector of claim 5 , wherein the magnetic field is configured to disperse the spent beam near and beyond a high voltage gap.
7. The depressed beam collector of claim 1 ,
wherein the magnetic lens comprises an iron pole piece at least partially surrounding the high voltage gap.
8. The depressed beam collector of claim 1 , wherein the depressed beam collector comprises space charge forces configured to disperse a trajectory of a decelerated spent beam.
9. The depressed beam collector of claim 1 , wherein the beam collector is a single-stage depressed beam collector.
10. The depressed beam collector of claim 1 , wherein the beam collector is a multi-stage depressed beam collector.
11. The depressed beam collector of claim 1 , further comprising cooling channels comprised in the grounded portion and the biased portion.
12. The depressed beam collector of claim 1 , wherein the depressed beam collector comprises a material having a low secondary emission coefficient.
13. The depressed beam collector of claim 1 , further comprising:
a coating of a material having a low secondary emission coefficient.
14. An RF source comprising:
an electron gun; and
a depressed beam collector including:
a grounded portion configured to collect a portion of electrons entering the collector;
a biased portion configured to collect another portion of the electrons entering the collector and having a depressed energy, wherein the grounded portion and the biased portion each form a portion of a wall of the depressed beam collector;
a high voltage gap comprising a spacing in the wall between the grounded portion and the biased portion; and
a magnetic lens at least partially surrounding the high voltage gap.
15. The RF source of claim 14 , wherein the electron gun is configured to emit a plurality of electron beams, and wherein the beam collector comprises a plurality of channels, each channel corresponding to one of the plurality of electron beams.
16. The RF source of claim 14 , wherein the biased portion is coupled to a depressed power supply at a collector voltage.
17. The RF source of claim 14 , wherein the magnetic lens is configured to suppress reflection of a spent beam.
18. The RF source of claim 14 , wherein the
magnetic lens comprises an iron pole piece at least partially surrounding the high voltage gap.
19. An RF source comprising:
a multi-beam klystron; and
a depressed beam collector including:
a grounded portion configured to collect a portion of electrons entering the collector;
a biased portion configured to collect another portion of the electrons entering the collector and having a depressed energy, wherein the grounded portion and the biased portion each form a portion of a wall of the depressed beam collector;
a high voltage gap comprising a spacing in the wall between the grounded portion and the biased portion; and
a magnetic lens at least partially surrounding the high voltage gap.
20. The RF source of claim 19 , wherein the biased portion is coupled to a depressed power supply at a collector voltage.