Quantum efficiency and thermal emittance of metal photocathodes
Modern electron beams have demonstrated the brilliance needed to drive free electron lasers at x-ray wavelengths with major advances occurring since the invention of the photocathode gun and the realization of emittance compensation. These state-of-the-art electron beams are now becoming limited by...
| Main Authors: | , |
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| Format: | Article |
| Language: | English |
| Published: |
American Physical Society
2009-07-01
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| Series: | Physical Review Special Topics. Accelerators and Beams |
| Online Access: | http://doi.org/10.1103/PhysRevSTAB.12.074201 |
| _version_ | 1818920576971964416 |
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| author | David H. Dowell John F. Schmerge |
| author_facet | David H. Dowell John F. Schmerge |
| author_sort | David H. Dowell |
| collection | DOAJ |
| description | Modern electron beams have demonstrated the brilliance needed to drive free electron lasers at x-ray wavelengths with major advances occurring since the invention of the photocathode gun and the realization of emittance compensation. These state-of-the-art electron beams are now becoming limited by the intrinsic thermal emittance of the cathode. In both dc and rf photocathode guns details of the cathode emission physics strongly influence the quantum efficiency and the thermal emittance. Therefore improving cathode performance is essential to increasing the brightness of beams. It is especially important to understand the fundamentals of cathode quantum efficiency and thermal emittance. This paper investigates the relationship between the quantum efficiency and the thermal emittance for metal cathodes using the Fermi-Dirac model for the electron distribution. We use a consistent theory to derive the quantum efficiency and thermal emittance, and compare our results to those of others. |
| first_indexed | 2024-12-20T01:23:57Z |
| format | Article |
| id | doaj.art-b6bfe871f16d48cc9bc0f6c341ed5d49 |
| institution | Directory Open Access Journal |
| issn | 1098-4402 |
| language | English |
| last_indexed | 2024-12-20T01:23:57Z |
| publishDate | 2009-07-01 |
| publisher | American Physical Society |
| record_format | Article |
| series | Physical Review Special Topics. Accelerators and Beams |
| spelling | doaj.art-b6bfe871f16d48cc9bc0f6c341ed5d492022-12-21T19:58:19ZengAmerican Physical SocietyPhysical Review Special Topics. Accelerators and Beams1098-44022009-07-0112707420110.1103/PhysRevSTAB.12.074201Quantum efficiency and thermal emittance of metal photocathodesDavid H. DowellJohn F. SchmergeModern electron beams have demonstrated the brilliance needed to drive free electron lasers at x-ray wavelengths with major advances occurring since the invention of the photocathode gun and the realization of emittance compensation. These state-of-the-art electron beams are now becoming limited by the intrinsic thermal emittance of the cathode. In both dc and rf photocathode guns details of the cathode emission physics strongly influence the quantum efficiency and the thermal emittance. Therefore improving cathode performance is essential to increasing the brightness of beams. It is especially important to understand the fundamentals of cathode quantum efficiency and thermal emittance. This paper investigates the relationship between the quantum efficiency and the thermal emittance for metal cathodes using the Fermi-Dirac model for the electron distribution. We use a consistent theory to derive the quantum efficiency and thermal emittance, and compare our results to those of others.http://doi.org/10.1103/PhysRevSTAB.12.074201 |
| spellingShingle | David H. Dowell John F. Schmerge Quantum efficiency and thermal emittance of metal photocathodes Physical Review Special Topics. Accelerators and Beams |
| title | Quantum efficiency and thermal emittance of metal photocathodes |
| title_full | Quantum efficiency and thermal emittance of metal photocathodes |
| title_fullStr | Quantum efficiency and thermal emittance of metal photocathodes |
| title_full_unstemmed | Quantum efficiency and thermal emittance of metal photocathodes |
| title_short | Quantum efficiency and thermal emittance of metal photocathodes |
| title_sort | quantum efficiency and thermal emittance of metal photocathodes |
| url | http://doi.org/10.1103/PhysRevSTAB.12.074201 |
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