Author: Honda, Y.
Paper Title Page
MOPAB330 Production and Performance Evaluation of a Compact Deflecting Cavity to Measure the Bunch Length in the cERL 1023
 
  • D. Naito, Y. Honda, T. Miyajima, N. Yamamoto
    KEK, Ibaraki, Japan
  
  At the KEK com­pact en­ergy re­cov­ery linac, we try to gen­er­ate an in­frared free-elec­tron laser (FEL). To gen­er­ate the FEL, an elec­tron bunch should be com­pressed along the lon­gi­tu­di­nal di­rec­tion. The mea­sure­ment of the bunch length is key to op­ti­mize the bunch com­pres­sion. We plan to mea­sure the bunch length by de­flect­ing cav­i­ties in the burst mode. The de­flect­ing cav­i­ties are re­quired to be a time res­o­lu­tion of 33 fs in order to not only mea­sure the bunch length but also re­solve the struc­ture in­side the elec­tron bunch. To achieve the re­quire­ment, we de­vel­oped a c-band cav­ity whose RF input port is com­pact. The de­flect­ing cav­ity is a sin­gle cell and nor­mal con­duct­ing cav­ity. The de­flec­tion mode of the cav­ity is TM110. The 12 cav­i­ties will be lo­cated at the exit of un­du­la­tors. In this pre­sen­ta­tion, we ex­plain the de­sign of our cav­ity and re­port the pro­duc­tion of the first cav­ity. We also re­port the eval­u­a­tion of the res­o­nance fre­quency, the un­loaded Q and the ex­ter­nal Q of the cav­ity. From the mea­sure­ments and sim­u­la­tions, the R/Q is es­ti­mated to be 1 mega orms. The time res­o­lu­tion of the cav­ity is ex­pected to be 400 fs when the input RF power is 1 kW and the beam en­ergy is 20 MeV.  
poster icon Poster MOPAB330 [12.920 MB]  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-MOPAB330  
About • paper received ※ 12 May 2021       paper accepted ※ 08 June 2021       issue date ※ 28 August 2021  
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TUPAB064 Specifications and Performance of a Chicane Magnet for the cERL IR-FEL 1512
 
  • N. Nakamura, K. Harada, N. Higashi, Y. Honda, R. Kato, C. Mitsuda, S. Nagahashi, T. Obina, H. Sakai, M. Shimada, H. Takaki, O.A. Tanaka
    KEK, Ibaraki, Japan
  • Y. Lu
    Sokendai, Ibaraki, Japan
  
  Funding: Work supported by NEDO project "Development of advanced laser processing with intelligence based high-brightness and high-efficiency laser technologies (TACMI project)".
The IR-FEL was con­structed in the Com­pact ERL (cERL) at KEK from Oc­to­ber 2019 to May 2020 for the pur­pose of de­vel­op­ing high-power mid-in­frared lasers for high-ef­fi­ciency laser pro­cess­ing uti­liz­ing mol­e­c­u­lar vi­bra­tional ab­sorp­tion. The chi­cane mag­net was newly in­stalled be­tween two IR-FEL un­du­la­tors in the cERL in order to in­crease the FEL gain and pulse en­ergy by con­vert­ing the en­ergy mod­u­la­tion to the den­sity mod­u­la­tion in an elec­tron bunch. It con­sists of three di­pole mag­nets with lam­i­nated yokes made of 0.1-mm-thick permal­loy sheets and the coil cur­rents of the three mag­nets are in­de­pen­dently con­trolled by three power sup­plies with the max­i­mum cur­rent of 10 A. The max­i­mum closed orbit bump made by the chi­cane mag­netic field has the lon­gi­tu­di­nal dis­per­sion(R56) of -6 mm. The coil-cur­rent ratio of the three di­pole mag­nets was tuned after in­stal­la­tion to make its orbit bumps closed and then the chi­cane mag­net was used in the FEL op­er­a­tion. We pre­sent spec­i­fi­ca­tions and op­er­a­tional per­for­mance of the chi­cane mag­net. 		 
poster icon Poster TUPAB064 [4.053 MB]  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-TUPAB064  
About • paper received ※ 18 May 2021       paper accepted ※ 25 May 2021       issue date ※ 25 August 2021  
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TUPAB099 Construction of an Infrared FEL at the Compact ERL 1608
 
  • R. Kato, M. Adachi, S. Eguchi, K. Harada, N. Higashi, Y. Honda, T. Miyajima, S. Nagahashi, N. Nakamura, K.N. Nigorikawa, T. Nogami, T. Obina, H. Sagehashi, H. Sakai, M. Shimada, T. Shioya, M. Tadano, R. Takai, O.A. Tanaka, Y. Tanimoto, K. Tsuchiya, T. Uchiyama, A. Ueda, M. Yamamoto
    KEK, Ibaraki, Japan
  • R. Hajima
    QST, Tokai, Japan
  • N.P. Norvell
    SLAC, Menlo Park, California, USA
  • F. Sakamoto
    Akita National College of Technology, Akita, Japan
  • M. Shimada
    HSRC, Higashi-Hiroshima, Japan
  
  Funding: Work supported by NEDO project "Development of advanced laser processing with intelligence based high-brightness and high-efficiency laser technologies (TACMI project)".
The com­pact En­ergy Re­cov­ery Linac (cERL) has been in op­er­a­tion at KEK since 2013 to demon­strate ERL per­for­mance and de­velop ERL tech­nol­ogy. Re­cently KEK has launched an in­frared FEL pro­ject with a com­pet­i­tive fund­ing. The pur­pose of this pro­ject is to build a mid-in­frared FEL at the cERL, and to use that FEL as a light source for con­struc­tion of the pro­cess­ing data­base re­quired for in­dus­trial lasers. The FEL sys­tem is com­posed of two 3-m un­du­la­tors and a match­ing sec­tion be­tween them, and gen­er­ates light with a max­i­mum pulse en­ergy of 0.1 mi­cro-J at the wave­length of 20 mi­crons with an 81.25 MHz rep­e­ti­tion rate. The FEL is also ex­pected to be­come a proof-of-con­cept ma­chine for ERL base FELs for fu­ture EUV lith­o­g­ra­phy. 		 
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-TUPAB099  
About • paper received ※ 20 May 2021       paper accepted ※ 14 June 2021       issue date ※ 29 August 2021  
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