Author: Deng, H.X.
Paper Title Page
MOP026
 Division-of-amplitude Photopolarimeter for Single-shot Measurement of Free Electron Laser at SDUV-FEL  
 
  • L. Feng, H.X. Deng, T. Zhang
    SINAP, Shanghai, People's Republic of China
  
  Di­vi­sion-of-am­pli­tude pho­topo­larime­ter (DOAP) is gen­er­ally used to mea­sure the po­lar­iza­tion-state of the pulse beam, which di­vides the in­ci­dent beam into four sep­a­rate beams, and all four Stokes pa­ra­me­ters can be mea­sured si­mul­ta­ne­ously. In this paper, a home-made DOAP in­stru­ment is ap­plied to the ex­per­i­ment of po­lar­iza­tion con­trol at Shang­hai deep ul­tra­vi­o­let FEL test fa­cil­ity. The re­sults in­di­cate that this in­stru­ment re­sponse fast and ac­cu­rately while the po­lar­iza­tion-state of the co­her­ent FEL are switched, and it is well ver­ify the cross-pla­nar un­du­la­tor tech­nique ex­per­i­men­tally.  
 
MOP070 Design Study for the PEHG Experiment at SDUV-FEL 219
 
  • C. Feng, H.X. Deng, B. Liu, D. Wang, X.T. Wang, M. Zhang, T. Zhang, W. Zhang, Z.T. Zhao
    SINAP, Shanghai, People's Republic of China
  
  Funding: This work was partially supported by National Natural Science Foundation of China (11475250, 11175240 and 11205234)
In this paper, de­sign stud­ies for the proof-of-prin­ci­ple ex­per­i­ment of the re­cently pro­posed phase-merg­ing en­hanced har­monic gen­er­a­tion (PEHG) mech­a­nism are pre­sented. A dog­leg and a new de­signed trans­verse gra­di­ent un­du­la­tor should be added in the un­du­la­tor sys­tem of SDUV-FEL to per­form the phase-merg­ing ef­fect. With the help of 3D sim­u­la­tion codes, we show the pos­si­ble per­for­mance of PEHG with the re­al­is­tic pa­ra­me­ters of SDUV-FEL.
* H. Deng, C. Feng, Phys. Rev. Lett. 111, 084801.
** C. Feng, H. Deng, D. Wang, Z. Zhao, New J. Phys.,16, 043021.
*** C. Feng, T. Zhang, H. Deng, Z. Zhao, Phys. Rev. ST Accel. Beams 17, 070701.
 		 
 
MOP072
 Preparation for the CPA-CHG Experiment at SDUV-FEL  
 
  • C. Feng, H.X. Deng, T. Lan, B. Li, B. Liu, D. Wang, X.T. Wang, Z.T. Zhao
    SINAP, Shanghai, People's Republic of China
  
  Chirped pulse am­pli­fi­ca­tion has been shown the­o­ret­i­cally pos­si­ble to gen­er­ate ul­tra-short high in­ten­sity ra­di­a­tion pulses in a seeded FEL. To demon­strate the the­o­ret­i­cal pre­dic­tions, a CPA-CHG ex­per­i­ment is under prepa­ra­tion based on the SDUV-FEL re­cently. We will show the ex­per­i­ment lay­out, op­ti­cal de­sign stud­ies and some pre­lim­i­nary mea­sure­ment re­sults of the op­ti­cal sys­tems in this paper.
* L. Yu, E. Johnson, D. Li, D. Umstader, Physical Review E 49 (1994) 4480
** C. Feng et al. Nuclear Instruments and Methods in Physics Research A 712 (2013) 113 		 
 
TUC04
 Experimental Demonstration of Seeded Free-electron Laser Spectrum Control using Corrugated Structure  
 
  • H.X. Deng, C. Feng, B. Liu, D. Wang, M. Zhang, T. Zhang, Z.T. Zhao
    SINAP, Shanghai, People's Republic of China
  
  Funding: This work was partially supported by the Major State Basic Research Development Program of China (2011CB808300) and the National Natural Science Foundation of China (11175240, 11205234 and 11322550).
Cor­ru­gated struc­tures [*] hold promis­ing prospects as beam lin­earizer, beam de-chirper and beam sta­bi­lizer for a high bright­ness LINAC, and thus en­hance the FEL per­for­mance sig­nif­i­cantly. So far, sev­eral elec­tron beam test ex­per­i­ments of cor­ru­gated struc­ture have been car­ried out on LINACs at PAL [**] and BNL [***]. More re­cently, a pas­sive con­trol ex­per­i­ment of FEL spec­trum, by using a pair of cor­ru­gated planes has been suc­cess­fully ac­c­mo­plished at SDUV-FEL, which is the first real FEL ex­per­i­men­tal demon­stra­tion of such wake­field struc­ture ap­pli­ca­tions. The phys­i­cal de­sign, nu­mer­i­cal sim­u­la­tions, the vac­uum cham­ber man­u­fac­ture and the ex­per­i­ment re­sults are pre­sented in this paper.
* K. L. F. Bane and G. Stupakov, NIMA 690 (2012) 106-110.
** P. Emma, M. Venturini, K. L. F. Bane, et al., PRL. 112 (2014) 034801.
*** M. Harrison, et al., NaPAc 2013, Pasadena, USA. 		 
slides icon Slides TUC04 [8.562 MB]  
 
FRB01
 Phase-merging Enhanced Harmonic Generation for Seeded Free-electron Lasers  
 
  • H.X. Deng, C. Feng, D. Wang, Z.T. Zhao
    SINAP, Shanghai, People's Republic of China
  
  Funding: This work was partially supported by the Major State Basic Research Development Program of China (2011CB808300) and the National Natural Science Foundation of China (11175240, 11205234, and 11322550)
The re­cently pro­posed phase-merg­ing en­hanced har­monic gen­er­a­tion (PEHG) mech­a­nism [*, **] holds promis­ing prospect for seeded free-elec­tron lasers (FEL) in short-wave­length. A re­mark­able bunch­ing ef­fi­ciency at high har­mon­ics can be ac­com­plished by using PEHG mech­a­nism. In this paper, the the­o­ret­i­cal de­scrip­tions and nu­mer­i­cal sim­u­la­tions of PEHG will be pre­sented, in­clud­ing the more re­cent the­o­ret­i­cal pro­gresses and a po­ten­tial proof-of-prin­ci­ple ex­per­i­ment at Shang­hai deep ul­tra­vi­o­let FEL test fa­cil­ity.
* Haixiao Deng, Chao Feng, Phys. Rev. Lett. 111 (2013) 084801.
** Chao Feng, Haixiao Deng, Dong Wang, Zhentang Zhao, New Journal of Physics,16 (2014) 043021. 		 
slides icon Slides FRB01 [29.808 MB]