FEL2013 - List of Keywords (radio-frequency)

Paper	Title	Other Keywords	Page
TUPSO17	Status of the Manufacturing Process for the SwissFEL C-Band Accelerating Structures	vacuum, laser, linac, coupling	245
	U. Ellenberger, H. Blumer, L. Paly, C. Zumbach Paul Scherrer Institute, Villigen PSI, Switzerland M. Bopp, H. Fitze, F. Löhl PSI, Villigen PSI, Switzerland
	For the SwissFEL project a total of 104 C-band (or approximately 6 GHz for 5’712 MHz required) accelerating structures are needed. After developing and RF-testing of several short structures (0.5m), three 2meter prototypes have been produced successfully in-house. Avoiding any RF-tuning after fabrication, a high precision machining of the components is necessary. Special procedures were developed and handling equipment was built in order to maintain the accuracy during stacking and vacuum brazing of the parts for the C-band structures. This paper summarizes the manufacturing techniques and the mechanical test results for constant subvolumes to match the required klystron frequency of 5’712 MHz

WEPSO33	Remote RF Synchronization With Femtosecond Drift at PAL	laser, electron, free-electron-laser, photon	570
	J. Kim, K. Jung, J. Lim KAIST, Daejeon, Republic of Korea L. Chen Idesta Quantum Electronics, New Jersey, USA S. Hunziker PSI, Villigen PSI, Switzerland F.X. Kaertner CFEL, Hamburg, Germany H.-S. Kang, C.-K. Min PAL, Pohang, Kyungbuk, Republic of Korea
	Funding: This research was supported by the PAL-XFEL Project, South Korea. We present our recent progress in remote RF synchronization using an optical way at PAL. A 79.33-MHz, low-jitter fiber laser is used as an optical master oscillator (OMO), which is locked to the 2.856-GHz RF master oscillator (RMO) using a balanced optical-microwave phase detector (BOM-PD). The locked optical pulse train is then transferred via a timing-stabilized 610-m long optical fiber link. The output is locked to the 2.856 GHz voltage controlled oscillator (VCO) using the second BOM-PD, which results in remote synchronization between the RMO and the VCO. We measured the long-term phase drift between the input optical pulse train and the remote RF signals using an out-of-loop BOM-PD, which results in 2.7 fs (rms) drift maintained over 7 hours. We are currently working to measure the phase drift between the two RF signals and reduce the phase drift over longer measurement time.

Paper

Title

Other Keywords

Page

TUPSO17

Status of the Manufacturing Process for the SwissFEL C-Band Accelerating Structures

vacuum, laser, linac, coupling

245

U. Ellenberger, H. Blumer, L. Paly, C. Zumbach
Paul Scherrer Institute, Villigen PSI, Switzerland
M. Bopp, H. Fitze, F. Löhl
PSI, Villigen PSI, Switzerland

For the SwissFEL project a total of 104 C-band (or approximately 6 GHz for 5’712 MHz required) accelerating structures are needed. After developing and RF-testing of several short structures (0.5m), three 2meter prototypes have been produced successfully in-house. Avoiding any RF-tuning after fabrication, a high precision machining of the components is necessary. Special procedures were developed and handling equipment was built in order to maintain the accuracy during stacking and vacuum brazing of the parts for the C-band structures. This paper summarizes the manufacturing techniques and the mechanical test results for constant subvolumes to match the required klystron frequency of 5’712 MHz

WEPSO33

Remote RF Synchronization With Femtosecond Drift at PAL

laser, electron, free-electron-laser, photon

570

J. Kim, K. Jung, J. Lim
KAIST, Daejeon, Republic of Korea
L. Chen
Idesta Quantum Electronics, New Jersey, USA
S. Hunziker
PSI, Villigen PSI, Switzerland
F.X. Kaertner
CFEL, Hamburg, Germany
H.-S. Kang, C.-K. Min
PAL, Pohang, Kyungbuk, Republic of Korea

Funding: This research was supported by the PAL-XFEL Project, South Korea.
We present our recent progress in remote RF synchronization using an optical way at PAL. A 79.33-MHz, low-jitter fiber laser is used as an optical master oscillator (OMO), which is locked to the 2.856-GHz RF master oscillator (RMO) using a balanced optical-microwave phase detector (BOM-PD). The locked optical pulse train is then transferred via a timing-stabilized 610-m long optical fiber link. The output is locked to the 2.856 GHz voltage controlled oscillator (VCO) using the second BOM-PD, which results in remote synchronization between the RMO and the VCO. We measured the long-term phase drift between the input optical pulse train and the remote RF signals using an out-of-loop BOM-PD, which results in 2.7 fs (rms) drift maintained over 7 hours. We are currently working to measure the phase drift between the two RF signals and reduce the phase drift over longer measurement time.