Reduction of multipacting by means of spatially varying magnetization
AssigneeCern - European Organization for Nuclear Research
InventorFritz Caspers
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Abstract
The present invention discloses an apparatus comprising an enclosure (10) suitable for forming a vacuum therein and means for at least partially suppressing the multipacting effect when a RF or microwave electromagnetic field is generated in said vacuum. In the apparatus, the means for at least partially suppressing the multipacting effect comprises means (12) for passively generating a locally varying magnetic field (16) in the vicinity of at least a portion of the inner surface of said enclosure.
Claims30
An apparatus comprising:
- an enclosure suitable for forming a vacuum interior to an inner surface of the enclosure;
- and
- means for at least partially suppressing a multipacting effect when a RF or microwave electromagnetic field is generated in said vacuum by decreasing a yield of secondary electrons, characterized in that said means for at least partially suppressing the multipacting effect comprises means for generating a locally varying magnetic field in the vicinity of at least a portion of the inner surface of said enclosure adapted for trapping at least a portion of the secondary electrons so as not to contribute to the yield of secondary electrons, wherein said means for at least partially suppressing the multipacting effect comprises a layer of ferromagnetic material which is statically magnetized such as to generate the locally varying magnetic field.
An apparatus comprising:
- an enclosure suitable for forming a vacuum interior to an inner surface of the enclosure;
- and
- means for at least partially suppressing a multipacting effect when a RF or microwave electromagnetic field is generated in said vacuum by decreasing a yield of secondary electrons, characterized in that said means for at least partially suppressing the multipacting effect comprises means for generating a locally varying magnetic field in the vicinity of at least a portion of the inner surface of said enclosure adapted for trapping at least a portion of the secondary electrons so as not to contribute to the yield of secondary electrons,
- wherein the apparatus comprises means for applying a macroscopic magnetic field and also comprises a non-uniform distribution of ferromagnetic material arranged in the vicinity of the inside surface of said enclosure such as to locally modulate a microscopic magnetic field.
A method of forming an apparatus in which a multipacting effect is at least partially suppressed, comprising the steps of:
- providing an enclosure that can be evacuated to a vacuum, and
- providing means for passively generating a locally varying magnetic field in the vicinity of at least a portion of the inner surface of said enclosure,
- wherein said step of providing means for passively generating a locally varying magnetic field comprises a step of providing a ferromagnetic layer in the vicinity of the inner surface of said enclosure and magnetizing the ferromagnetic layer according to a locally varying pattern.
A method of at least partially suppressing a multipacting effect in a vacuum enclosure in which an RF or microwave electromagnetic field is generated, characterized in that a yield of secondary electrons is decreased by trapping at least a portion of the secondary electrons in a locally varying magnetic field created by providing a layer of ferromagnetic material in the vicinity of at least a portion of the inner surface of said enclosure, wherein the layer of ferromagnetic material is statically magnetized such as to generate said locally varying magnetic field.
Dependencies are inferred from the claim text.