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Diamond Amplifier for Phtotocathodes.

DE200415009620

Publication Date	2004
Personal Author	Rao, T.; Ben-Zvi, I.; Burrill, A.
Page Count	20
Abstract	We report a new approach to the generation of high-current, high-brightness electron beams. Primary electrons are produced by a photocathode (or other means) and are accelerated to a few thousand electron-volts, then strike a specially prepared diamond window. The large Secondary Electron Yield (SEY) provides a multiplication of the number of electrons by about two orders of magnitude. The secondary electrons drift through the diamond under an electric field and emerge into the accelerating proper of the 'gun' through a Negative Electron Affinity surface of the diamond. The advantages of the new approach include the following: 1. Reduction of the number of primary electrons by the large SEY, i.e. a very low laser power in a photocathode producing the primaries. 2. Low thermal emittance due to the NEA surface and the rapid thermalization of the electrons.3. Protection of the cathode from possible contamination from the gun, allowing the use of large quantum efficiency but sensitive cathodes. 4. Protection of the gun from possible contamination by the cathode, allowing the use of superconducting gun cavities. 5. Production of high average currents, up to ampere class. 6. Encapsulated design, making the 'load-lock' systems unnecessary. This paper presents the criteria that need to be taken into account in designing the amplifier.
Keywords	Photocathodes Electron beams Amplifier design High brightness RF systems Negative electron affinity Laser power beaming Thermalization Superconductivity Accelerator-based systems Secondary Electron Yield (SEY) Thermal emittance
Source Agency	Technical Information Center Oak Ridge Tennessee
Corporate Authors	Brookhaven National Lab., Upton, NY.; Department of Energy, Washington, DC.
Supplemental Notes	Sponsored by Department of Energy, Washington, DC.
Document Type	Technical Report
NTIS Issue Number	200513

Diamond Amplifier for Phtotocathodes.

Diamond Amplifier for Phtotocathodes.
DE200415009620

Publication Date	2004
Personal Author	Rao, T.; Ben-Zvi, I.; Burrill, A.
Page Count	20
Abstract	We report a new approach to the generation of high-current, high-brightness electron beams. Primary electrons are produced by a photocathode (or other means) and are accelerated to a few thousand electron-volts, then strike a specially prepared diamond window. The large Secondary Electron Yield (SEY) provides a multiplication of the number of electrons by about two orders of magnitude. The secondary electrons drift through the diamond under an electric field and emerge into the accelerating proper of the 'gun' through a Negative Electron Affinity surface of the diamond. The advantages of the new approach include the following: 1. Reduction of the number of primary electrons by the large SEY, i.e. a very low laser power in a photocathode producing the primaries. 2. Low thermal emittance due to the NEA surface and the rapid thermalization of the electrons.3. Protection of the cathode from possible contamination from the gun, allowing the use of large quantum efficiency but sensitive cathodes. 4. Protection of the gun from possible contamination by the cathode, allowing the use of superconducting gun cavities. 5. Production of high average currents, up to ampere class. 6. Encapsulated design, making the 'load-lock' systems unnecessary. This paper presents the criteria that need to be taken into account in designing the amplifier.
Keywords	Photocathodes Electron beams Amplifier design High brightness RF systems Negative electron affinity Laser power beaming Thermalization Superconductivity Accelerator-based systems Secondary Electron Yield (SEY) Thermal emittance
Source Agency	Technical Information Center Oak Ridge Tennessee
Corporate Authors	Brookhaven National Lab., Upton, NY.; Department of Energy, Washington, DC.
Supplemental Notes	Sponsored by Department of Energy, Washington, DC.
Document Type	Technical Report
NTIS Issue Number	200513