Title :
Measurement with beam of the deflecting higher order modes in the TTF superconducting cavities
Author :
Magne, Ch ; Jablonka, M. ; Lalot, M. ; Lethiers, V. ; Luong, M. ; Napoly, O. ; Baboi, N. ; Castro, P. ; Gössel, A. ; Hüning, M. ; Kreps, G. ; Liepe, M. ; Minty, M. ; Schreiber, S. ; Sertore, D. ; Wendt, M.
Author_Institution :
CEA, Centre d´´Etudes Nucleaires de Saclay, Gif-sur-Yvette, France
Abstract :
This paper reports on recent beam measurements of higher order modes in the TESLA Test Facility (TTF) accelerating modules. Using bunch trains of about 0.5 ms with 54 MHz bunch repetition and up to 90% modulated intensity, transverse higher order modes are resonantly excited when the beam is offset and their frequency on resonance with the modulation frequency. With this method, the trapped modes can be excited and their counteraction on the beam observed on a wide-band BPM downstream of the module. Scanning the modulation frequency from 0 to 27 MHz allows a systematic investigation of all possible dangerous modes in the modules
Keywords :
accelerator cavities; electron accelerators; linear accelerators; particle beam diagnostics; superconducting cavity resonators; 0 to 27 MHz; 54 MHz; TESLA Test Facility; TTF; higher order modes; superconducting cavities; transverse higher order modes; trapped modes; Damping; Frequency modulation; Intensity modulation; Linear particle accelerator; Optical modulation; Optical pulses; Passband; Pulse modulation; Resonance; Superconducting magnets;
Conference_Titel :
Particle Accelerator Conference, 2001. PAC 2001. Proceedings of the 2001
Conference_Location :
Chicago, IL
Print_ISBN :
0-7803-7191-7
DOI :
10.1109/PAC.2001.988248
