FEL2013 - List of Authors (Bopp, M.)

Paper	Title	Page
TUPSO17	Status of the Manufacturing Process for the SwissFEL C-Band Accelerating Structures	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

TUPSO21	SwissFEL Cathode Load-lock System	259
	R. Ganter, M. Bopp, N. Gaiffi, T. Le Quang, M. Pedrozzi, M. Schaer, T. Schietinger, L. Schulz, L. Stingelin, A. Trisorio PSI, Villigen PSI, Switzerland
	The SwissFEL electron source is an RF photo-injector in which the photo-cathode plug can be exchanged. Without load-lock, the cathode exchange takes about one week and cathode surface gets contaminated in the atmosphere during installation, leading to unpredictable quantum efficiency (QE) fluctuations. This motivated the construction of a load lock system to prepare and insert cathodes in the photo-injector. This load lock system consists of three parts: the preparation chamber, the transportable vacuum suitcase and the gun load lock chamber. This three parts system gives the possibility to prepare the cathode surface with methods like vacuum firing and plasma cleaning. The QE can be checked and the plug can be inserted in the gun without breaking vacuum. This will allow establishing an optimized a reproducible cathode preparation procedure. Since several cathodes can be loaded in advance, the exchange procedure reduces the machine shutdown to a few hours (shorter RF conditioning). The system is described and first experience with its use is reported.

TUPSO43	Status of the SwissFEL C-band Linear Accelerator	317
	F. Löhl, J. Alex, H. Blumer, M. Bopp, H.-H. Braun, A. Citterio, H. Fitze, H. Jöhri, T. Kleeb, L. Paly, J.-Y. Raguin, L. Schulz, R. Zennaro PSI, Villigen PSI, Switzerland U. Ellenberger Paul Scherrer Institute, Villigen PSI, Switzerland
	This paper will summarize the status of the linear accelerator of the Swiss free-electron laser SwissFEL. It will be based on C-band technology and will use solid-state modulators and a novel type of C-band accelerating structures which has been designed at PSI. Initial test results of first 2 m long structures will be presented together with measurements performed with the first BOC-type pulse compressors. Furthermore, we will present first results of a water cooling system for the accelerating structures and the pulse compressors.

Paper

Title

Page

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

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

TUPSO21

SwissFEL Cathode Load-lock System

259

R. Ganter, M. Bopp, N. Gaiffi, T. Le Quang, M. Pedrozzi, M. Schaer, T. Schietinger, L. Schulz, L. Stingelin, A. Trisorio
PSI, Villigen PSI, Switzerland

The SwissFEL electron source is an RF photo-injector in which the photo-cathode plug can be exchanged. Without load-lock, the cathode exchange takes about one week and cathode surface gets contaminated in the atmosphere during installation, leading to unpredictable quantum efficiency (QE) fluctuations. This motivated the construction of a load lock system to prepare and insert cathodes in the photo-injector. This load lock system consists of three parts: the preparation chamber, the transportable vacuum suitcase and the gun load lock chamber. This three parts system gives the possibility to prepare the cathode surface with methods like vacuum firing and plasma cleaning. The QE can be checked and the plug can be inserted in the gun without breaking vacuum. This will allow establishing an optimized a reproducible cathode preparation procedure. Since several cathodes can be loaded in advance, the exchange procedure reduces the machine shutdown to a few hours (shorter RF conditioning). The system is described and first experience with its use is reported.

TUPSO43

Status of the SwissFEL C-band Linear Accelerator

317

F. Löhl, J. Alex, H. Blumer, M. Bopp, H.-H. Braun, A. Citterio, H. Fitze, H. Jöhri, T. Kleeb, L. Paly, J.-Y. Raguin, L. Schulz, R. Zennaro
PSI, Villigen PSI, Switzerland
U. Ellenberger
Paul Scherrer Institute, Villigen PSI, Switzerland

This paper will summarize the status of the linear accelerator of the Swiss free-electron laser SwissFEL. It will be based on C-band technology and will use solid-state modulators and a novel type of C-band accelerating structures which has been designed at PSI. Initial test results of first 2 m long structures will be presented together with measurements performed with the first BOC-type pulse compressors. Furthermore, we will present first results of a water cooling system for the accelerating structures and the pulse compressors.