Author: Geloni, G.
Paper Title Page
TUPEA005 Effects of Quantum Diffusion on Electron Trajectories and Spontaneous Synchrotron Radiation Emission 1170
 
  • I.V. Agapov, G. Geloni
    XFEL. EU, Hamburg, Germany
  • O.V. Chubar
    BNL, Upton, Long Island, New York, USA
  
  For var­i­ous cases, e.g. in the long un­du­la­tor sec­tions of the Eu­ro­pean XFEL, quan­tum dif­fu­sion and en­ergy loss have a not­i­ca­ble ef­fect on the elec­tron tra­jec­tory, which in turn af­fects the prop­er­ties of the emit­ted ra­di­a­tion. We dis­cuss ap­proaches to mod­el­ling the elec­tron dy­nam­ics tak­ing this into ac­count and the ef­fect it has on spon­ta­neous ra­di­a­tion emis­sion.  
 
TUPEA006 Towards Realistic Modelling of the FEL Radiation for the European XFEL 1173
 
  • I.V. Agapov, G. Geloni
    XFEL. EU, Hamburg, Germany
  
  For the op­er­a­tion phase of the Eu­ro­pean XFEL the pos­si­bil­ity to char­ac­ter­ize the FEL ra­di­a­tion tak­ing re­al­is­tic ma­chine model into ac­count is im­por­tant. To achieve this, a soft­ware frame­work is being de­vel­oped. It al­lows for in­ter­op­er­abil­ity of var­i­ous sim­u­la­tion codes by means of a com­mon graph­i­cal user in­ter­faces, com­mon input and out­put files, and com­mon pro­gram­ming model for script­ing; it in­cludes the pos­si­bil­ity of mod­el­ing beam jit­ters and ma­chine im­per­fec­tions to set er­ror­bars on the sim­u­la­tion re­sults, and has a con­nec­tion to the con­trol sys­tem for data ac­qui­si­tion. We re­port on the progress in the de­vel­op­ing of this frame­work and give ex­am­ples of FEL prop­erty cal­cu­la­tions per­formed with it.  
 
TUPEA007 Spontaneous Radiation Calculations for the European XFEL 1176
 
  • I.V. Agapov, G. Geloni
    XFEL. EU, Hamburg, Germany
  • O.V. Chubar
    BNL, Upton, Long Island, New York, USA
  • M. Scheer, M. Titze
    HZB, Berlin, Germany
  • N.V. Smolyakov, S.I. Tomin
    NRC, Moscow, Russia
  
  Cal­cu­lat­ing spon­ta­neous ra­di­a­tion emis­sion from long un­du­la­tors such as those pre­sent in the Eu­ro­pean XFEL, being back­ground to FEL ra­di­a­tion, is still im­por­tant for sev­eral di­ag­nos­tics and sci­ence cases. For re­al­is­tic se­tups, and in­clud­ing ef­fects of elec­tron beam fo­cus­ing, emit­tance and en­ergy spread in the elec­tron beam, these cal­cu­la­tions should be per­formed nu­mer­i­cally. We pre­sent these cal­cu­la­tions for sev­eral elec­tron beam and un­du­la­tor pa­ra­me­ters per­formed by var­i­ous codes. Sen­si­tiv­ity of dif­fer­ent spon­ta­neous ra­di­a­tion char­ac­ter­is­tics, in var­i­ous col­lec­tion schemes, to the elec­tron beam and un­du­la­tor mag­netic field pa­ra­me­ters is stud­ied  
 
WEPWA044 Electron Trajectories in a Three-dimensional Undulator Magnetic Field 2223
 
  • N.V. Smolyakov, S.I. Tomin
    NRC, Moscow, Russia
  • G. Geloni
    XFEL. EU, Hamburg, Germany
  
  In this con­tri­bu­tion we pre­sent an analy­sis of elec­tron tra­jec­to­ries in the three di­men­sional mag­netic field from a pla­nar un­du­la­tor. The elec­tron tra­jec­tory is in­flu­enced by the fo­cus­ing prop­er­ties of the un­du­la­tor field. In the Eu­ro­pean XFEL case, long seg­mented un­du­la­tors (21 seg­ments for the SASE3 beam­line to 35 for SASE1 and SASE2) are planned to be in­stalled, with quadru­pole lenses be­tween dif­fer­ent seg­ments. These fo­cus­ing prop­er­ties should be taken into ac­count in sim­u­la­tions of spon­ta­neous ra­di­a­tion, which con­sti­tutes the back­ground sig­nal of the FEL. The ideal mag­netic field of an un­du­la­tor can be de­scribed by a si­nu­soidal ver­ti­cal mag­netic field on the un­du­la­tor axis, and by hor­i­zon­tal and lon­gi­tu­di­nal field com­po­nents that ap­pear out of axis. Ex­ploit­ing this de­scrip­tion for the ideal case, an ex­per­i­men­tally mea­sured mag­netic field is ac­counted for by solv­ing the dif­fer­en­tial equa­tions of mo­tion. The elec­trons' tra­jec­to­ries for the ex­per­i­men­tally mea­sured mag­netic field were also sim­u­lated nu­mer­i­cally. To that aim, a com­puter code was writ­ten, which re­lies on the Runge-Kutta al­go­rithm. The an­a­lyt­i­cal and nu­mer­i­cal meth­ods show a good agree­ment.