Author: Xu, H.
Paper Title Page
MOZE4 Ceramic Enhanced Accelerator Structure Low Power Test and Designs of High Power and Beam Tests 49
 
  • H. Xu, M.R. Bradley, L.D. Duffy, M.A. Holloway, J. Upadhyay
    LANL, Los Alamos, New Mexico, USA
 
  Funding: Research was supported by the Laboratory Directed Research and Development program of Los Alamos National Laboratory, under project number 20210083ER.
A ce­ramic en­hanced ac­cel­er­a­tor struc­ture (CEAS) uses a con­cen­tric ce­ramic ring placed in­side a metal­lic pill­box cav­ity to sig­nif­i­cantly in­crease the shunt im­ped­ance of the cav­ity. Sin­gle cell stand­ing wave CEAS cav­i­ties are de­signed, built, and tested at low power at 5.1 GHz. The re­sults in­di­cate 40% in­crease in shunt im­ped­ance com­pared to that of a purely metal­lic pill­box cav­ity. A beam test setup has been de­signed to use a sin­gle cell CEAS cav­ity to mod­u­late a 30-keV di­rect-cur­rent (DC) elec­tron beam at an ac­cel­er­at­ing gra­di­ent of 1 to 2 MV/m to ver­ify the beam ac­cel­er­a­tion ca­pa­bil­ity of the CEAS con­cept and to study the po­ten­tial charg­ing ef­fect on the ce­ramic com­po­nent dur­ing the op­er­a­tion. An­other sin­gle cell stand­ing wave CEAS cav­ity has been de­signed for high power test at 5.7 GHz for the high ac­cel­er­at­ing gra­di­ent ca­pa­bil­ity.
 
slides icon Slides MOZE4 [1.652 MB]  
DOI • reference for this paper ※ doi:10.18429/JACoW-NAPAC2022-MOZE4  
About • Received ※ 01 August 2022 — Revised ※ 07 August 2022 — Accepted ※ 09 August 2022 — Issue date ※ 07 October 2022
Cite • reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)  
 
TUPA72 Comparison Study on First Bunch Compressor Schemes by Conventional and Double C-Chicane for MaRIE XFEL 496
 
  • H. Xu, P.M. Anisimov, L.D. Duffy, Q.R. Marksteiner
    LANL, Los Alamos, New Mexico, USA
 
  Funding: Laboratory Directed Research and Development program of Los Alamos National Laboratory, project number 20200287ER.
We re­port our com­par­i­son study on the first stage elec­tron bunch com­pres­sion schemes at 750 MeV using a con­ven­tional and a dou­ble C-chi­cane for the X-ray free elec­tron laser (XFEL) under de­vel­op­ment for the Mat­ter-Ra­di­a­tion In­ter­ac­tions in Ex­tremes (MaRIE) ini­tia­tive at Los Alamos Na­tional Lab­o­ra­tory. Com­pared to the per­for­mance of the con­ven­tional C-chi­cane bunch com­pres­sor, the dou­ble C-chi­cane scheme ex­hibits the ca­pa­bil­ity of uti­liz­ing the trans­verse mo­men­tum shift in­duced by the co­her­ent syn­chro­tron ra­di­a­tion in the sec­ond C-chi­cane to com­pen­sate that gen­er­ated in the first C-chi­cane, re­sult­ing in a com­pressed elec­tron bunch with min­i­mized trans­verse mo­men­tum shift along the beam. It is also found that the dou­ble C-chi­cane scheme can be de­signed to sig­nif­i­cantly bet­ter pre­serve the beam emit­tance in the course of the bunch com­pres­sion. This is par­tic­u­larly ben­e­fi­cial for the MaRIE XFEL whose las­ing per­for­mance crit­i­cally de­pends on the preser­va­tion of the ul­tralow beam emit­tance.
 
poster icon Poster TUPA72 [1.339 MB]  
DOI • reference for this paper ※ doi:10.18429/JACoW-NAPAC2022-TUPA72  
About • Received ※ 01 August 2022 — Accepted ※ 06 August 2022 — Issue date ※ 15 August 2022  
Cite • reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)  
 
TUPA73 Design and Low Power Test of an Electron Bunching Enhancer Using Electrostatic Potential Depression 499
 
  • H. Xu, B.E. Carlsten, Q.R. Marksteiner
    LANL, Los Alamos, New Mexico, USA
  • B.L. Beaudoin, T.W. Koeth, A. Ting
    UMD, College Park, Maryland, USA
 
  Funding: This project was supported by the U.S. Department of Energy Office of Science through the Accelerator Stewardship Program.
We pre­sent our ex­per­i­men­tal de­sign and low power test re­sults of a struc­ture for the proof-of-prin­ci­ple demon­stra­tion of fast in­crease of the first har­monic cur­rent con­tent in a bunched elec­tron beam, using the tech­nique of elec­tro­sta­tic po­ten­tial de­pres­sion (EPD). A pri­mar­ily bunched elec­tron beam from an in­duc­tive out­put tube (IOT) at 710 MHz first en­ters an idler cav­ity, where the lon­gi­tu­di­nal slope of the beam en­ergy dis­tri­b­u­tion is re­versed. The beam then tran­sits through an EPD sec­tion im­ple­mented by a short beam pipe with a neg­a­tive high volt­age bias, in­side which the rate of in­crease of the first har­monic cur­rent is sig­nif­i­cantly en­hanced. An out­put cav­ity mea­sures the har­monic cur­rent de­vel­oped in­side the beam down­stream of the EPD sec­tion. Low power test re­sults of the idler and the out­put cav­i­ties agree with the the­o­ret­i­cal de­sign.
 
poster icon Poster TUPA73 [1.307 MB]  
DOI • reference for this paper ※ doi:10.18429/JACoW-NAPAC2022-TUPA73  
About • Received ※ 29 July 2022 — Accepted ※ 03 August 2022 — Issue date ※ 09 August 2022  
Cite • reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)  
 
TUPA74 Numerical Calculations of Wave Generation from a Bunched Electron Beam in Space 502
 
  • H. Xu, G.L. Delzanno, L.D. Duffy, Q.R. Marksteiner, G.D. Reeves
    LANL, Los Alamos, New Mexico, USA
 
  Funding: This project was supported by the Laboratory Directed Research and Development program of Los Alamos National Laboratory.
We pre­sent our nu­mer­i­cal ap­proach and pre­lim­i­nary re­sults of the cal­cu­la­tions of whistler and X-mode wave gen­er­a­tion by a bunched elec­tron beam in space. The ar­ti­fi­cial gen­er­a­tion of whistler and X-mode plasma waves in space is among the can­di­date tech­niques to ac­com­plish the ra­di­a­tion belt re­me­di­a­tion (RBR), in an ef­fort to pre­cip­i­tate en­er­getic elec­trons to­wards the at­mos­phere to re­duce their threat to low-Earth orbit satel­lites. Free-space prop­a­ga­tion of an elec­tron pulse in a con­stant back­ground mag­netic field was sim­u­lated with the CST par­ti­cle-in-cell (PIC) solver, with the tem­po­ral evo­lu­tion of the beam recorded. The Spec­tralPlas­ma­Solver (SPS) was then mod­i­fied to use the recorded elec­tron pulse prop­a­ga­tion to cal­cu­late the real-time plasma waves gen­er­ated by the beam. SPS sim­u­la­tion re­sults of the wave gen­er­a­tion for the up­com­ing Beam-PIE ex­per­i­ment as well as an ideal bunched elec­tron beam are shown.
 
poster icon Poster TUPA74 [0.963 MB]  
DOI • reference for this paper ※ doi:10.18429/JACoW-NAPAC2022-TUPA74  
About • Received ※ 18 July 2022 — Revised ※ 02 August 2022 — Accepted ※ 07 August 2022 — Issue date ※ 08 August 2022
Cite • reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)  
 
FRXD4 Suppressing the Microbunching Instability at ATF using Laser Assisted Bunch Compression 914
 
  • Q.R. Marksteiner, P.M. Anisimov, B.E. Carlsten, G. Latour, E.I. Simakov, H. Xu
    LANL, Los Alamos, New Mexico, USA
 
  Funding: This project was supported by funding from the Los Alamos National Laboratory Laboratory Research and Development program.
The mi­crobunch­ing in­sta­bil­ity in lin­ear ac­cel­er­a­tors can sig­nif­i­cantly in­crease the en­ergy spread of an elec­tron beam. The in­sta­bil­ity can be sup­pressed by ar­ti­fi­cially in­creas­ing the ran­dom en­ergy spread of an elec­tron beam, but this leads to un­ac­cept­ably high en­ergy spreads for fu­ture XFEL sys­tems. One pos­si­bil­ity of sup­press­ing this in­sta­bil­ity is to use laser as­sisted bunch com­pres­sion (LABC) in­stead of the sec­ond chi­cane in an XFEL sys­tem, thereby elim­i­nat­ing the cas­caded chi­cane ef­fect that mag­ni­fies the mi­crobunch­ing in­sta­bil­ity. An ex­per­i­ment is pro­posed at ATF to test this con­cept, and nu­mer­i­cal sim­u­la­tions of the ex­per­i­ment are shown.
 
slides icon Slides FRXD4 [4.629 MB]  
DOI • reference for this paper ※ doi:10.18429/JACoW-NAPAC2022-FRXD4  
About • Received ※ 03 August 2022 — Revised ※ 11 August 2022 — Accepted ※ 12 August 2022 — Issue date ※ 28 September 2022
Cite • reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)