Low-emittance radio-frequency electron gun using a gridded thermionic cathode
We developed an electron gun system capable of delivering high brightness beams to drive soft x-ray free-electron lasers (SXFEL). We modified the conventional radio-frequency (rf) gun concept by using a 50-kV gun with a gridded thermionic cathode connected with a 238-MHz acceleration cavity. We achi...
| Main Authors: | , , , , , , , |
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| Format: | Article |
| Language: | English |
| Published: |
American Physical Society
2020-06-01
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| Series: | Physical Review Accelerators and Beams |
| Online Access: | http://doi.org/10.1103/PhysRevAccelBeams.23.063401 |
| _version_ | 1830354670561787904 |
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| author | Takao Asaka Takahiro Inagaki Tamotsu Magome Nobuyuki Nishimori Yuji Otake Tsutomu Taniuchi Kenich Yanagida Hitoshi Tanaka |
| author_facet | Takao Asaka Takahiro Inagaki Tamotsu Magome Nobuyuki Nishimori Yuji Otake Tsutomu Taniuchi Kenich Yanagida Hitoshi Tanaka |
| author_sort | Takao Asaka |
| collection | DOAJ |
| description | We developed an electron gun system capable of delivering high brightness beams to drive soft x-ray free-electron lasers (SXFEL). We modified the conventional radio-frequency (rf) gun concept by using a 50-kV gun with a gridded thermionic cathode connected with a 238-MHz acceleration cavity. We achieved a low target emittance by applying the following two methods: (1) to obtain a parallel beam after the control grid, we optimized the grid voltage to compensate for the electric potential distortion near the grid (i.e., the lens effect); and (2) to avoid emittance growth due to the space charge effect at low energy regions, the 50-kV gun was connected to a 238-MHz rf cavity with a minimum distance, which immediately accelerated the beam energy to 500 keV. We built a gun test stand to verify the high beam performance, i.e., a normalized emittance of less than 4 mm mrad with a bunch charge of 1 nC and a pulse length shorter than 0.7 ns, as predicted by cst and parmela codes. Our proof-of-performance experiments demonstrated that a projection emittance of 1.7 mm mrad was obtained as a core part, representing 60% of all extracted electrons and the measured emittance agreed well with the simulation value of 2.0 mm mrad. This paper presents an overview of the electron gun system and our proof-of-performance experimental results. |
| first_indexed | 2024-12-20T01:34:26Z |
| format | Article |
| id | doaj.art-dd9707f39a534fe8acc47b94bcf47971 |
| institution | Directory Open Access Journal |
| issn | 2469-9888 |
| language | English |
| last_indexed | 2024-12-20T01:34:26Z |
| publishDate | 2020-06-01 |
| publisher | American Physical Society |
| record_format | Article |
| series | Physical Review Accelerators and Beams |
| spelling | doaj.art-dd9707f39a534fe8acc47b94bcf479712022-12-21T19:58:02ZengAmerican Physical SocietyPhysical Review Accelerators and Beams2469-98882020-06-0123606340110.1103/PhysRevAccelBeams.23.063401Low-emittance radio-frequency electron gun using a gridded thermionic cathodeTakao AsakaTakahiro InagakiTamotsu MagomeNobuyuki NishimoriYuji OtakeTsutomu TaniuchiKenich YanagidaHitoshi TanakaWe developed an electron gun system capable of delivering high brightness beams to drive soft x-ray free-electron lasers (SXFEL). We modified the conventional radio-frequency (rf) gun concept by using a 50-kV gun with a gridded thermionic cathode connected with a 238-MHz acceleration cavity. We achieved a low target emittance by applying the following two methods: (1) to obtain a parallel beam after the control grid, we optimized the grid voltage to compensate for the electric potential distortion near the grid (i.e., the lens effect); and (2) to avoid emittance growth due to the space charge effect at low energy regions, the 50-kV gun was connected to a 238-MHz rf cavity with a minimum distance, which immediately accelerated the beam energy to 500 keV. We built a gun test stand to verify the high beam performance, i.e., a normalized emittance of less than 4 mm mrad with a bunch charge of 1 nC and a pulse length shorter than 0.7 ns, as predicted by cst and parmela codes. Our proof-of-performance experiments demonstrated that a projection emittance of 1.7 mm mrad was obtained as a core part, representing 60% of all extracted electrons and the measured emittance agreed well with the simulation value of 2.0 mm mrad. This paper presents an overview of the electron gun system and our proof-of-performance experimental results.http://doi.org/10.1103/PhysRevAccelBeams.23.063401 |
| spellingShingle | Takao Asaka Takahiro Inagaki Tamotsu Magome Nobuyuki Nishimori Yuji Otake Tsutomu Taniuchi Kenich Yanagida Hitoshi Tanaka Low-emittance radio-frequency electron gun using a gridded thermionic cathode Physical Review Accelerators and Beams |
| title | Low-emittance radio-frequency electron gun using a gridded thermionic cathode |
| title_full | Low-emittance radio-frequency electron gun using a gridded thermionic cathode |
| title_fullStr | Low-emittance radio-frequency electron gun using a gridded thermionic cathode |
| title_full_unstemmed | Low-emittance radio-frequency electron gun using a gridded thermionic cathode |
| title_short | Low-emittance radio-frequency electron gun using a gridded thermionic cathode |
| title_sort | low emittance radio frequency electron gun using a gridded thermionic cathode |
| url | http://doi.org/10.1103/PhysRevAccelBeams.23.063401 |
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