Paper  Title  Other Keywords  Page 

SUPB031  The Nonresonant Perturbation Theory Based Field Measurement and Tuning of a Linac Accelerating Structure  linac, RFstructure, pickup, feedback  80 


Assisted by the bead pull technique, the nonresonant perturbation theory is applied for measuring and tuning the field of the linac accelerating structure. The method is capable of making nontouch measurement, amplitude and phase diagnostics, real time mismatch feedback and field tuning. Main considerations on measurement system and of Cband travelingwave structure are described, the bead pull measurement and the tuning of the Cband travelingwave linac accelerating structure are presented.  
MOPB022  RF Characteristic Studies on the Whole Accelerating Structure for the BEPCII Linear Accelerator  linac, simulation, vacuum, impedance  219 


An accelerating structure is one device to boost the particle energy. 2856 MHz 3 m long travelling wave diskloaded accelerating structure is applied in BEPCII linac, its RF characteristics are mainly determined by the 84 regular cells located between the input and output couplers. Input and output couplers need to be included when the whole structure RF characteristics are simulated before fabrication; otherwise it would be difficult to obtain the travelling wave fields excited in the whole structure. If the real 3D couplers are modelled during the design process, a large amount of computer resources and time need to be used. However, if the redesigned azimuth symmetric coupler is used to replace the real 3D one during the simulation process, much less computer resources and time are required. With this method proposed here, the simulation results agree well with the theoretically calculated and experimentally measured ones.
*peisl@ihep.ac.cn 

MOPB086  The Nonresonant Perturbation Theory Based Field Measurement and Tuning of a Linac Accelerating Structure  linac, RFstructure, pickup, feedback  375 


Assisted by the bead pull technique, the nonresonant perturbation theory is applied for measuring and tuning the field of the linac accelerating structure. The method is capable of making nontouch measurement, amplitude and phase diagnostics, real time mismatch feedback and field tuning. Main considerations on measurement system and of Cband travelingwave structure are described, the bead pull measurement and the tuning of the Cband travelingwave linac accelerating structure are presented.  
TUPLB02  Deflecting Structures with Minimized Level of Aberrations  controls, emittance, diagnostics, RFstructure  445 


Funding: in part RBFR N 120200654a Deflecting structures are now widely used for bunch phase space manipulations either in bunch rotation for special bunch diagnostic or in emittance exchange experiments. As a tool for manipulation, the structure itself should provide the minimal phase space perturbations due to non linear additives in the field distribution. Even if the field of synchronous harmonic is aberration free, the higher space harmonics provide significant non linear additives in the field distribution, leading to emittance growth during phase space manipulation. Criterion of the field quality estimation is developed and deflecting structures are considered for minimization of non linear additives. Examples with almost aberration free total field distributions are presented. 

Slides TUPLB02 [0.727 MB]  
TUPB002  Deflecting Structures with Minimized Level of Aberrations  controls, emittance, diagnostics, RFstructure  476 


Funding: in part RBFR N 120200654a Deflecting structures are now widely used for bunch phase space manipulations either in bunch rotation for special bunch diagnostic or in emittance exchange experiments. As a tool for manipulation, the structure itself should provide the minimal phase space perturbations due to non linear additives in the field distribution. Even if the field of synchronous harmonic is aberration free, the higher space harmonics provide significant non linear additives in the field distribution, leading to emittance growth during phase space manipulation. Criterion of the field quality estimation is developed and deflecting structures are considered for minimization of non linear additives. Examples with almost aberration free total field distributions are presented. 
