R&D ERL: Photocathode Deposition and Transport System

doi:https://doi.org/10.2172/1013451

Title: R&D ERL: Photocathode Deposition and Transport System

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Abstract

The purpose of the photocathode deposition and transport system is to (1) produce a robust, high yield multialkali photocathode and (2) have a method of transporting the multialkali photocathode for insertion into a super conducting RF electron gun. This process is only successful if a sufficient quantum efficiency lifetime of the cathode, which is inserted in the SRF electron gun, is maintained. One important element in producing a multialkali photocathode is the strict vacuum requirements of 10{sup -11} torr to assure success in the production of longlived photocathodes that will not have their QE or lifetime depleted due to residual gas poisoning in a poor vacuum. A cutaway view of our third generation deposition system is shown in figure 1. There are certain design criteria and principles required. One must be able to install, remove, rejuvenate and replace a cathode without exposing the source or cathode to atmosphere. The system must allow one to deposit Cs, K, and Sb on a cathode tip surface at pressures in the 10{sup -10} to 10{sup -9} torr range. The cathode needs to be heated to as high as 850 C for cleaning and maintained at 130 C to 150 C during deposition. Theremore »« less

Authors:: Pate, D; Ben-Zvi, I; Rao, T; Burrill, R; Todd, R; Smedley, J; Holmes, D

Publication Date:: 2010-01-01

Research Org.:: Brookhaven National Laboratory (BNL) Relativistic Heavy Ion Collider

Sponsoring Org.:: DOE - Office Of Science

OSTI Identifier:: 1013451

Report Number(s):: BNL-90928-2010-IR
R&D Project: KBCH139; KB0202011; TRN: US1102648

DOE Contract Number:: DE-AC02-98CH10886

Resource Type:: Technical Report

Country of Publication:: United States

Language:: English

Subject:: 43 PARTICLE ACCELERATORS; CATHODES; CLEANING; DEPOSITION; DESIGN; ELECTRON GUNS; ENERGY RECOVERY; ION SOURCES; LIFETIME; LINEAR ACCELERATORS; PHOTOCATHODES; QUANTUM EFFICIENCY; RF SYSTEMS; SUPERCONDUCTING CAVITY RESONATORS; TRANSPORT; relativistic heavy ion collider

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                    Pate, D, Ben-Zvi, I, Rao, T, Burrill, R, Todd, R, Smedley, J, and Holmes, D. R&D ERL: Photocathode Deposition and Transport System.  United States: N. p., 2010. 
        Web.  doi:10.2172/1013451.

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                    Pate, D, Ben-Zvi, I, Rao, T, Burrill, R, Todd, R, Smedley, J, & Holmes, D. R&D ERL: Photocathode Deposition and Transport System.  United States.  https://doi.org/10.2172/1013451

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                    Pate, D, Ben-Zvi, I, Rao, T, Burrill, R, Todd, R, Smedley, J, and Holmes, D. Fri .  
        "R&D ERL: Photocathode Deposition and Transport System".  United States.  https://doi.org/10.2172/1013451.  https://www.osti.gov/servlets/purl/1013451.

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@article{osti_1013451,

  title        = {R&D ERL: Photocathode Deposition and Transport System},

  author       = {Pate, D and Ben-Zvi, I and Rao, T and Burrill, R and Todd, R and Smedley, J and Holmes, D},

  abstractNote = {The purpose of the photocathode deposition and transport system is to (1) produce a robust, high yield multialkali photocathode and (2) have a method of transporting the multialkali photocathode for insertion into a super conducting RF electron gun. This process is only successful if a sufficient quantum efficiency lifetime of the cathode, which is inserted in the SRF electron gun, is maintained. One important element in producing a multialkali photocathode is the strict vacuum requirements of 10{sup -11} torr to assure success in the production of longlived photocathodes that will not have their QE or lifetime depleted due to residual gas poisoning in a poor vacuum. A cutaway view of our third generation deposition system is shown in figure 1. There are certain design criteria and principles required. One must be able to install, remove, rejuvenate and replace a cathode without exposing the source or cathode to atmosphere. The system must allow one to deposit Cs, K, and Sb on a cathode tip surface at pressures in the 10{sup -10} to 10{sup -9} torr range. The cathode needs to be heated to as high as 850 C for cleaning and maintained at 130 C to 150 C during deposition. There should also be the capability for in-situ QE measurements. In addition the preparation of dispenser photocathodes must be accounted for, thus requiring an ion source for cathode cleaning. Finally the transport cart must be mobile and be able to negotiate the ERL facility labyrinth.},

  doi          = {10.2172/1013451},

  url          = {https://www.osti.gov/biblio/1013451},
  journal      = {},
number       = ,

  volume       = ,

  place        = {United States},

  year         = {2010},

  month        = {1}

}

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