FEL2012 - List of Authors (Hakobyan, L.)

Paper	Title	Page
MOPD60	Optimization of the Transverse Projected Emittance of the Electron Beam at PITZ	185
	G. Vashchenko, M. Groß, L. Hakobyan, I.I. Isaev, Ye. Ivanisenko, M. Krasilnikov, M. Mahgoub, D. Malyutin, A. Oppelt, M. Otevřel, B. Petrosyan, S. Rimjaem, A. Shapovalov, F. Stephan DESY Zeuthen, Zeuthen, Germany G. Asova INRNE, Sofia, Bulgaria M. Khojoyan ANSL, Yerevan, Armenia D. Richter HZB, Berlin, Germany
	High brightness electron sources for linac based free-electron lasers operating at short wavelength such as the Free-Electron Laser in Hamburg at DESY, Hamburg Site (FLASH) and the European X-Ray Laser Project XFEL (European XFEL) are characterized and optimized at the Photo Injector Test Facility at DESY, Zeuthen Site (PITZ). One of the most important parameters influencing the FEL process is the normalized transverse projected emittance of the electron beam. The major part of the experimental program at PITZ is devoted to its optimization. Detailed simulations of the present facility setup are performed for a 1 nC bunch charge in order to optimize the transverse projected emittance of the electron beam. Cathode laser pulse length and transverse spot size at the photo cathode, gun and booster accelerating gradients and their launching phases as well as the main solenoid current are optimized. Simulations results together with experimental data are presented.

MOPD61	Laser Pulse Train Management with an Acousto-optic Modulator	189
	M. Groß, H.-J. Grabosch, L. Hakobyan, I.I. Isaev, Ye. Ivanisenko, M. Khojoyan, G. Klemz, G. Kourkafas, M. Krasilnikov, K. Kusoljariyakul, J. Li, M. Mahgoub, D. Malyutin, B. Marchetti, A. Oppelt, M. Otevřel, B. Petrosyan, A. Shapovalov, F. Stephan, G. Vashchenko DESY Zeuthen, Zeuthen, Germany D. Richter HZB, Berlin, Germany H. Schlarb, S. Schreiber DESY, Hamburg, Germany
	Photo injector laser systems for linac based FELs often have the capability of generating pulse trains with an adjustable length. For example, the currently installed laser at the Photo Injector Test Facility at DESY, Zeuthen Site (PITZ) can generate pulse trains containing up to 800 pulses. Repetition frequencies are 10 Hz for the pulse trains and 1 MHz for the pulses within a train, respectively. Mostly due to thermal effects caused by absorption in amplifier and frequency doubling crystals, pulse properties are changing slightly within a pulse train and also shot-to-shot, depending on the pulse train length. To increase stability and repeatability of the laser it is desirable to run it under constant conditions. To achieve this while still being able to freely choose pulse patterns a pulse picker to sort the wanted from the unwanted pulses can be installed at the laser output. A promising candidate for this functionality is an acousto-optic modulator which currently is being tested at PITZ. First experimental results will be presented and discussed towards the possibility of including this device into an FEL photo injector.

Paper

Title

Page

Optimization of the Transverse Projected Emittance of the Electron Beam at PITZ

185

G. Vashchenko, M. Groß, L. Hakobyan, I.I. Isaev, Ye. Ivanisenko, M. Krasilnikov, M. Mahgoub, D. Malyutin, A. Oppelt, M. Otevřel, B. Petrosyan, S. Rimjaem, A. Shapovalov, F. Stephan
DESY Zeuthen, Zeuthen, Germany
G. Asova
INRNE, Sofia, Bulgaria
M. Khojoyan
ANSL, Yerevan, Armenia
D. Richter
HZB, Berlin, Germany

High brightness electron sources for linac based free-electron lasers operating at short wavelength such as the Free-Electron Laser in Hamburg at DESY, Hamburg Site (FLASH) and the European X-Ray Laser Project XFEL (European XFEL) are characterized and optimized at the Photo Injector Test Facility at DESY, Zeuthen Site (PITZ). One of the most important parameters influencing the FEL process is the normalized transverse projected emittance of the electron beam. The major part of the experimental program at PITZ is devoted to its optimization. Detailed simulations of the present facility setup are performed for a 1 nC bunch charge in order to optimize the transverse projected emittance of the electron beam. Cathode laser pulse length and transverse spot size at the photo cathode, gun and booster accelerating gradients and their launching phases as well as the main solenoid current are optimized. Simulations results together with experimental data are presented.

MOPD61

Laser Pulse Train Management with an Acousto-optic Modulator

189

M. Groß, H.-J. Grabosch, L. Hakobyan, I.I. Isaev, Ye. Ivanisenko, M. Khojoyan, G. Klemz, G. Kourkafas, M. Krasilnikov, K. Kusoljariyakul, J. Li, M. Mahgoub, D. Malyutin, B. Marchetti, A. Oppelt, M. Otevřel, B. Petrosyan, A. Shapovalov, F. Stephan, G. Vashchenko
DESY Zeuthen, Zeuthen, Germany
D. Richter
HZB, Berlin, Germany
H. Schlarb, S. Schreiber
DESY, Hamburg, Germany

Photo injector laser systems for linac based FELs often have the capability of generating pulse trains with an adjustable length. For example, the currently installed laser at the Photo Injector Test Facility at DESY, Zeuthen Site (PITZ) can generate pulse trains containing up to 800 pulses. Repetition frequencies are 10 Hz for the pulse trains and 1 MHz for the pulses within a train, respectively. Mostly due to thermal effects caused by absorption in amplifier and frequency doubling crystals, pulse properties are changing slightly within a pulse train and also shot-to-shot, depending on the pulse train length. To increase stability and repeatability of the laser it is desirable to run it under constant conditions. To achieve this while still being able to freely choose pulse patterns a pulse picker to sort the wanted from the unwanted pulses can be installed at the laser output. A promising candidate for this functionality is an acousto-optic modulator which currently is being tested at PITZ. First experimental results will be presented and discussed towards the possibility of including this device into an FEL photo injector.