ICALEPCS2013 - List of Authors (Szewinski, J.)

Paper

Title

Page

From Pulse to Continuous Wave Operation of TESLA Cryomodules – LLRF System Software Modification and Development

1366

W. Cichalewski, W. Jałmużna, A. Piotrowski, K.P. Przygoda
TUL-DMCS, Łódź, Poland
V. Ayvazyan, J. Branlard, H. Schlarb, J.K. Sekutowicz
DESY, Hamburg, Germany
J. Szewiński
NCBJ, Świerk/Otwock, Poland

Funding: We acknowledge the support from National Science Center (Poland) grant no 5593/B/T02/2010/39
Higher efficiency of TESLA based free electron lasers (FLASH, XFEL) by means of increased quantity of photon bursts can be achieved using continuous wave operation mode. In order to maintain constant beam acceleration in superconducting cavities and keep short pulse to CW operation transition costs reasonably low some substantial modification of accelerator subsystems are necessary. Changes in: RF power source, cryo systems, electron beam source, etc. have to be also accompanied by adjustments in LLRF system. In this paper challenges for well established pulsed mode LLRF system are discussed (in case of CW and LP scenarios). Firmware, software modifications needed for maintaining high performance of cavities field parameters regulation (for 1Hz CW and LP cryo-module operation) are described. Results from studies of vector sum amplitude and phase control in case of resonators high Ql factor settings (Ql~1.5e7) are shown. Proposed modifications implemented in VME and microTCA (MTCA.4) based LLRF system has been tested during studies at CryoModule Test Bench (CMTB) in DESY. Results from this tests together with achieved regulation performance data are also presented and discussed.

Poster THPPC135 [1.310 MB]

THPPC140

MTCA Upgrade of the Readout Electronics for the Bunch Arrival Time Monitor at FLASH

1380

J. Szewiński, G. Boltruczyk, S. Korolczuk
NCBJ, Świerk/Otwock, Poland
S. Bou Habib, J. Dobosz, D. Sikora
Warsaw University of Technology, Institute of Electronic Systems, Warsaw, Poland
C. Gerth, H. Schlarb
DESY, Hamburg, Germany

Bunch Arrival time Monitor (BAM) is an electro-optical device used at FLASH accelerator in DESY for the high precision, femtosecond scale, measurements of the moment when electron bunch arrives at the reference point in the machine. The arrival time is proportional to the average bunch energy, and is used to calculate the amplitude correction for RF field control. Correction is sent to the LLRF system in less than 10 us, and this creates a secondary feedback loop (over the regular LLRF one), which is focused on beam energy stabilization - beam feedback. This paper presents new uTCA BAM readout electronics design based on the uTCA.4 – “uTCA for Physics” and FMC mezzanine boards standards. Presented solution is a replacement for existing, VME based BAM readout devices. It provides higher efficiency by using new measurement techniques, better components (such as ADCs, FPGAs etc.), and high bandwidth uTCA backplane. uTCA provides also different topology for data transfers in the crate, which all together opens new opportunities for the improvement of the overall system performance.

Poster THPPC140 [14.281 MB]

Paper	Title	Page
THPPC135	From Pulse to Continuous Wave Operation of TESLA Cryomodules – LLRF System Software Modification and Development	1366
	W. Cichalewski, W. Jałmużna, A. Piotrowski, K.P. Przygoda TUL-DMCS, Łódź, Poland V. Ayvazyan, J. Branlard, H. Schlarb, J.K. Sekutowicz DESY, Hamburg, Germany J. Szewiński NCBJ, Świerk/Otwock, Poland
	Funding: We acknowledge the support from National Science Center (Poland) grant no 5593/B/T02/2010/39 Higher efficiency of TESLA based free electron lasers (FLASH, XFEL) by means of increased quantity of photon bursts can be achieved using continuous wave operation mode. In order to maintain constant beam acceleration in superconducting cavities and keep short pulse to CW operation transition costs reasonably low some substantial modification of accelerator subsystems are necessary. Changes in: RF power source, cryo systems, electron beam source, etc. have to be also accompanied by adjustments in LLRF system. In this paper challenges for well established pulsed mode LLRF system are discussed (in case of CW and LP scenarios). Firmware, software modifications needed for maintaining high performance of cavities field parameters regulation (for 1Hz CW and LP cryo-module operation) are described. Results from studies of vector sum amplitude and phase control in case of resonators high Ql factor settings (Ql~1.5e7) are shown. Proposed modifications implemented in VME and microTCA (MTCA.4) based LLRF system has been tested during studies at CryoModule Test Bench (CMTB) in DESY. Results from this tests together with achieved regulation performance data are also presented and discussed.
	Poster THPPC135 [1.310 MB]

THPPC140	MTCA Upgrade of the Readout Electronics for the Bunch Arrival Time Monitor at FLASH	1380
	J. Szewiński, G. Boltruczyk, S. Korolczuk NCBJ, Świerk/Otwock, Poland S. Bou Habib, J. Dobosz, D. Sikora Warsaw University of Technology, Institute of Electronic Systems, Warsaw, Poland C. Gerth, H. Schlarb DESY, Hamburg, Germany
	Bunch Arrival time Monitor (BAM) is an electro-optical device used at FLASH accelerator in DESY for the high precision, femtosecond scale, measurements of the moment when electron bunch arrives at the reference point in the machine. The arrival time is proportional to the average bunch energy, and is used to calculate the amplitude correction for RF field control. Correction is sent to the LLRF system in less than 10 us, and this creates a secondary feedback loop (over the regular LLRF one), which is focused on beam energy stabilization - beam feedback. This paper presents new uTCA BAM readout electronics design based on the uTCA.4 – “uTCA for Physics” and FMC mezzanine boards standards. Presented solution is a replacement for existing, VME based BAM readout devices. It provides higher efficiency by using new measurement techniques, better components (such as ADCs, FPGAs etc.), and high bandwidth uTCA backplane. uTCA provides also different topology for data transfers in the crate, which all together opens new opportunities for the improvement of the overall system performance.
	Poster THPPC140 [14.281 MB]