FEL2011 - List of Authors (Hoffmann, M.)

Paper	Title	Page
THPA06	Emittance for Different Bunch Charges at the Upgraded PITZ Facility	473
	S. Rimjaem, G. Asova, H.-J. Grabosch, M. Groß, L. Hakobyan, I.I. Isaev, Ye. Ivanisenko, M.A. Khojoyan, G. Klemz, M. Krasilnikov, M. Mahgoub, D. Malyutin, A. Oppelt, M. Otevřel, B. Petrosyan, A. Shapovalov, F. Stephan, G. Vashchenko, S. Weidinger DESY Zeuthen, Zeuthen, Germany M. Hoffmann, H. Schlarb DESY, Hamburg, Germany M.A. Nozdrin JINR, Dubna, Moscow Region, Russia D. Richter HZB, Berlin, Germany I.H. Templin, I. Will MBI, Berlin, Germany
	Optimizations of electron sources for short-wavelength Free Electron Laser (FELs) at the Photo Injector Test facility at DESY, location Zeuthen (PITZ) have been continued with a new radio frequency (RF) gun cavity, a new post-accelerating Cut Disk Structure (CDS) booster cavity and several upgraded diagnostic components. The new booster cavity allows stable operation with higher acceleration and longer pulse trains than the operation with the previous TESLA type cavity. Electron beams with a maximum mean momentum of about 25 MeV/c can be produced with the setup described in this paper. Together with the upgraded RF system for the gun and the new CDS booster cavity, the electron beam stability was significantly improved. A large fraction of the measurement program in 2010-2011was devoted to study the dependence of the transverse projected emittance on the bunch charge. Measurement results using this upgraded facility are reported and discussed.

THPA10	RF Photo Gun Stability Measurement at PITZ	485
	I.I. Isaev, G. Asova, H.-J. Grabosch, M. Groß, L. Hakobyan, Ye. Ivanisenko, G. Klemz, W. Köhler, M. Krasilnikov, M. Mahgoub, D. Malyutin, A. Oppelt, M. Otevřel, B. Petrosyan, S. Rimjaem, F. Stephan, G. Vashchenko, S. Weidinger, R.W. Wenndorff DESY Zeuthen, Zeuthen, Germany M. Hoffmann, H. Schlarb DESY, Hamburg, Germany M.A. Khojoyan ANSL, Yerevan, Armenia D. Richter BESSY GmbH, Berlin, Germany A. Shapovalov MEPhI, Moscow, Russia
	High stability of the RF photo gun is one of the necessary conditions for the successful operation of linac based free electron lasers. Fluctuations of the RF launch phase have significant influence on the beam quality. Investigation on the dependence of different gun parameters and selection of optimal conditions are required to achieve high RF gun phase stability. Measurements of the gun RF phase stability are based on beam charge and momentum monitoring downstream of the gun. The stability of the RF gun phase for different operating conditions has been measured at the Photo Injector Test facility at DESY in Zeuthen (PITZ) and the results will be presented.

THPA12	Beam Energy Measurements in the FLASH Injector using Synchrotron Radiation and Bunch Arrival Monitors	489
	C. Gerth, M.K. Bock, M. Hoffmann, F. Ludwig, H. Schlarb, Ch. Schmidt DESY, Hamburg, Germany
	The high beam energy stability required for stable operation of linac-driven free-electron lasers demands for precise cavity RF field regulation. This is in particular true for the accelerator modules at low beam energies which are used to induce an energy correlation on the electron beam for longitudinal bunch compression in magnetic chicanes. At FLASH, a major upgrade of the injector has taken place in the shutdown 2009/2010 including the installation of a 3rd harmonic accelerating module, exchange of modulators and re-cabling and temperature stabilization of the low-level RF electronics. Several beam-based techniques have been developed recently which can be used to monitor the beam energy with high precision or as fast feedbacks for the RF regulation. In this paper, we report on bunch-resolved energy measurements recorded independently with a synchrotron radiation monitor and two bunch arrival monitors. Good agreement between the monitors was found and the measurement data are compared with the results from RF detection.

Paper

Title

Page

Emittance for Different Bunch Charges at the Upgraded PITZ Facility

473

S. Rimjaem, G. Asova, H.-J. Grabosch, M. Groß, L. Hakobyan, I.I. Isaev, Ye. Ivanisenko, M.A. Khojoyan, G. Klemz, M. Krasilnikov, M. Mahgoub, D. Malyutin, A. Oppelt, M. Otevřel, B. Petrosyan, A. Shapovalov, F. Stephan, G. Vashchenko, S. Weidinger
DESY Zeuthen, Zeuthen, Germany
M. Hoffmann, H. Schlarb
DESY, Hamburg, Germany
M.A. Nozdrin
JINR, Dubna, Moscow Region, Russia
D. Richter
HZB, Berlin, Germany
I.H. Templin, I. Will
MBI, Berlin, Germany

Optimizations of electron sources for short-wavelength Free Electron Laser (FELs) at the Photo Injector Test facility at DESY, location Zeuthen (PITZ) have been continued with a new radio frequency (RF) gun cavity, a new post-accelerating Cut Disk Structure (CDS) booster cavity and several upgraded diagnostic components. The new booster cavity allows stable operation with higher acceleration and longer pulse trains than the operation with the previous TESLA type cavity. Electron beams with a maximum mean momentum of about 25 MeV/c can be produced with the setup described in this paper. Together with the upgraded RF system for the gun and the new CDS booster cavity, the electron beam stability was significantly improved. A large fraction of the measurement program in 2010-2011was devoted to study the dependence of the transverse projected emittance on the bunch charge. Measurement results using this upgraded facility are reported and discussed.

THPA10

RF Photo Gun Stability Measurement at PITZ

485

I.I. Isaev, G. Asova, H.-J. Grabosch, M. Groß, L. Hakobyan, Ye. Ivanisenko, G. Klemz, W. Köhler, M. Krasilnikov, M. Mahgoub, D. Malyutin, A. Oppelt, M. Otevřel, B. Petrosyan, S. Rimjaem, F. Stephan, G. Vashchenko, S. Weidinger, R.W. Wenndorff
DESY Zeuthen, Zeuthen, Germany
M. Hoffmann, H. Schlarb
DESY, Hamburg, Germany
M.A. Khojoyan
ANSL, Yerevan, Armenia
D. Richter
BESSY GmbH, Berlin, Germany
A. Shapovalov
MEPhI, Moscow, Russia

High stability of the RF photo gun is one of the necessary conditions for the successful operation of linac based free electron lasers. Fluctuations of the RF launch phase have significant influence on the beam quality. Investigation on the dependence of different gun parameters and selection of optimal conditions are required to achieve high RF gun phase stability. Measurements of the gun RF phase stability are based on beam charge and momentum monitoring downstream of the gun. The stability of the RF gun phase for different operating conditions has been measured at the Photo Injector Test facility at DESY in Zeuthen (PITZ) and the results will be presented.

THPA12

Beam Energy Measurements in the FLASH Injector using Synchrotron Radiation and Bunch Arrival Monitors

489

C. Gerth, M.K. Bock, M. Hoffmann, F. Ludwig, H. Schlarb, Ch. Schmidt
DESY, Hamburg, Germany

The high beam energy stability required for stable operation of linac-driven free-electron lasers demands for precise cavity RF field regulation. This is in particular true for the accelerator modules at low beam energies which are used to induce an energy correlation on the electron beam for longitudinal bunch compression in magnetic chicanes. At FLASH, a major upgrade of the injector has taken place in the shutdown 2009/2010 including the installation of a 3rd harmonic accelerating module, exchange of modulators and re-cabling and temperature stabilization of the low-level RF electronics. Several beam-based techniques have been developed recently which can be used to monitor the beam energy with high precision or as fast feedbacks for the RF regulation. In this paper, we report on bunch-resolved energy measurements recorded independently with a synchrotron radiation monitor and two bunch arrival monitors. Good agreement between the monitors was found and the measurement data are compared with the results from RF detection.