Author: Han, J.H.
Paper Title Page
TUPB18 Preliminary Studies of a Possible Normal-conducting Linac Option for the UK's New Light Sourc 295
 
  • R.P. Walker, C. Christou, J.H. Han
    Diamond, Oxfordshire, United Kingdom
  • R. Bartolini
    JAI, Oxford, United Kingdom
  
  A Con­cep­tual De­sign Re­port for a major new soft-Xray light source fa­cil­ity for the UK, the New Light Source (NLS), based on high rep­e­ti­tion rate free-elec­tron lasers dri­ven by a cw su­per­con­duct­ing L-band linac was com­pleted in May 2010. While the sci­ence case for such a fa­cil­ity was con­sid­ered very strong, due to fund­ing re­stric­tions the NLS de­sign pro­ject, sup­ported by STFC and Di­a­mond Light Source, was ter­mi­nated after com­ple­tion of the CDR. Since then we have been giv­ing some pre­lim­i­nary con­sid­er­a­tions to a pos­si­ble al­ter­na­tive op­tion for the NLS which could pro­vide sim­i­lar per­for­mance but at re­duced rep­e­ti­tion rate, and po­ten­tially re­duced cost, based on nor­mal con­duct­ing tech­nol­ogy. In this re­port we sum­marise the work done so far, in­clud­ing pos­si­ble op­er­at­ing pa­ra­me­ters and per­for­mance, as well as an as­sess­ment of rel­a­tive costs of dif­fer­ent fre­quency op­tions.  
 
THPB29 Design of a Low Emittance and High Repetition Rate S-band Photoinjector 621
 
  • J.H. Han
    Diamond, Oxfordshire, United Kingdom
  
  One of key com­po­nents for the suc­cess of X-ray free-elec­tron lasers (FELs) is the elec­tron in­jec­tor. In­jec­tors start­ing with pho­to­cath­ode RF guns pro­vide ex­cep­tion­ally high bright­ness elec­tron beams and there­fore they are being adopted as in­jec­tors of X-ray FELs. In this paper we show how to im­prove the pho­toin­jec­tor per­for­mance in terms of emit­tance and rep­e­ti­tion rate by means of com­po­nents op­ti­miza­tion based on ma­ture tech­nolo­gies. Trans­verse emit­tance at an in­jec­tor is re­duced by op­ti­miz­ing the RF gun cav­ity de­sign, gun so­le­noid po­si­tion, and ac­cel­er­at­ing sec­tion po­si­tion. The rep­e­ti­tion rate of an in­jec­tor mainly de­pends on the cool­ing ca­pa­bil­ity of the gun cav­ity. By adopt­ing the coax­ial RF gun cou­pler and im­prov­ing cool­ing-wa­ter chan­nels of the gun, a max­i­mum rep­e­ti­tion rate of 1 kHz for the in­jec­tor will be achieved.