IPAC2012 - List of Authors (Doebert, S.)

Paper	Title	Page
TUPPD066	Lifetime Studies of Cs2Te Cathodes at the PHIN RF Photoinjector at CERN	1554
	C. Heßler, E. Chevallay, M. Divall Csatari, S. Döbert, V. Fedosseev CERN, Geneva, Switzerland
	The PHIN photoinjector has been developed to study the feasibility of a photoinjector option for the CLIC (Compact LInear Collider) drive beam as an alternative to the baseline design, using a thermionic gun. The CLIC drive beam requires a high charge of 8.4 nC per bunch in 0.14 ms long trains, with 500 MHz bunch spacing and 50 Hz macro pulse repetition rate, which corresponds to a total charge per macro pulse of 0.59 mC. This means unusually high peak and average currents for photoinjectors and is challenging with respect to the cathode lifetime. In this paper detailed studies of the lifetime of Cs2Te cathodes, produced by the co-evaporation technique, with respect to bunch charge, train length and vacuum level are presented. Furthermore, the impact of the train length and bunch charge on the vacuum level will be discussed and steps to extend the lifetime will be outlined.

TUPPR031	Experimental Verification of the CLIC Decelerator with theTest Beam Line in the CLIC Test Facility 3	1885
	R.L. Lillestøl, S. Döbert, M. Olvegård, A. Rabiller, G. Sterbini CERN, Geneva, Switzerland E. Adli University of Oslo, Oslo, Norway
	The Test Beam Line in the CLIC Test Facility 3 is the first prototype of the CLIC drive beam decelerator. The main purpose of the experiment is to demonstrate efficient 12 GHz rf power production and stable transport of an electron drive beam during deceleration. The Test Beam Line consists of a FODO structure with high precision BPMs and quadrupoles mounted on mechanical movers for precise beam alignment. Nine out of the planned 16 Power Extraction and Transfer Structures have currently been installed and commissioned. We correlate rf power production measurements with the drive beam deceleration measurements, and compare the two measurements to the theoretical predictions. We also discuss the impact of the drive beam bunch length and bunch combination on the measurements.

TUPPR034	Beam-based Alignment in CTF3 Test Beam Line	1894
	G. Sterbini, S. Döbert, R.L. Lillestøl, E. Marín, D. Schulte CERN, Geneva, Switzerland E. Adli University of Oslo, Oslo, Norway
	The CLIC linear collider is based on the two beams acceleration scheme. During acceleration, the drive beam suffers a large increase in its energy spread. In order to efficiently transport such a beam, beam-based alignment techniques together with tight pre-alignment tolerances are crucial. A beam-based steering campaign has been conducted at the Test Beam Line of the CLIC Test Facility to evaluate the performance of several algorithms. In the following we present and discuss the obtained results.

THPPC060	Commissioning of the First Klystron-based X-band Power Source at CERN	3428
	J.W. Kovermann, N. Catalan-Lasheras, S. Curt, S. Döbert, G. McMonagle, S.F. Rey, G. Riddone, K.M. Schirm, I. Syratchev, L. Timeo CERN, Geneva, Switzerland J.P. Eichner, A.A. Haase, D.W. Sprehn SLAC, Menlo Park, California, USA A. Hamdi, F. Peauger CEA/DSM/IRFU, France
	A new klystron based x-band rf power source working at 11.994GHz has been installed and commissioned at CERN in collaboration with CEA Saclay and SLAC for CLIC accelerating structure tests. The system comprises a solid state high voltage modulator, an XL5 klystron developed by SLAC, a cavity based SLED type pulse compressor, the necessary low level rf system including rf diagnostics and interlocks and the surrounding vacuum, cooling and controls infrastructure. The klystron can produce up to 50MW rf pulses of 1500ns pulse width and 50Hz repetition rate. After pulse compression, up to 100MW of rf power at 250ns pulse with are available in the structure test bunker. This paper describes in more detail this setup and the results of the commissioning which was necessary to arrive at the mentioned performance.

Paper

Title

Page

Lifetime Studies of Cs2Te Cathodes at the PHIN RF Photoinjector at CERN

1554

C. Heßler, E. Chevallay, M. Divall Csatari, S. Döbert, V. Fedosseev
CERN, Geneva, Switzerland

The PHIN photoinjector has been developed to study the feasibility of a photoinjector option for the CLIC (Compact LInear Collider) drive beam as an alternative to the baseline design, using a thermionic gun. The CLIC drive beam requires a high charge of 8.4 nC per bunch in 0.14 ms long trains, with 500 MHz bunch spacing and 50 Hz macro pulse repetition rate, which corresponds to a total charge per macro pulse of 0.59 mC. This means unusually high peak and average currents for photoinjectors and is challenging with respect to the cathode lifetime. In this paper detailed studies of the lifetime of Cs2Te cathodes, produced by the co-evaporation technique, with respect to bunch charge, train length and vacuum level are presented. Furthermore, the impact of the train length and bunch charge on the vacuum level will be discussed and steps to extend the lifetime will be outlined.

TUPPR031

Experimental Verification of the CLIC Decelerator with theTest Beam Line in the CLIC Test Facility 3

1885

R.L. Lillestøl, S. Döbert, M. Olvegård, A. Rabiller, G. Sterbini
CERN, Geneva, Switzerland
E. Adli
University of Oslo, Oslo, Norway

The Test Beam Line in the CLIC Test Facility 3 is the first prototype of the CLIC drive beam decelerator. The main purpose of the experiment is to demonstrate efficient 12 GHz rf power production and stable transport of an electron drive beam during deceleration. The Test Beam Line consists of a FODO structure with high precision BPMs and quadrupoles mounted on mechanical movers for precise beam alignment. Nine out of the planned 16 Power Extraction and Transfer Structures have currently been installed and commissioned. We correlate rf power production measurements with the drive beam deceleration measurements, and compare the two measurements to the theoretical predictions. We also discuss the impact of the drive beam bunch length and bunch combination on the measurements.

TUPPR034

Beam-based Alignment in CTF3 Test Beam Line

1894

G. Sterbini, S. Döbert, R.L. Lillestøl, E. Marín, D. Schulte
CERN, Geneva, Switzerland
E. Adli
University of Oslo, Oslo, Norway

The CLIC linear collider is based on the two beams acceleration scheme. During acceleration, the drive beam suffers a large increase in its energy spread. In order to efficiently transport such a beam, beam-based alignment techniques together with tight pre-alignment tolerances are crucial. A beam-based steering campaign has been conducted at the Test Beam Line of the CLIC Test Facility to evaluate the performance of several algorithms. In the following we present and discuss the obtained results.

THPPC060

Commissioning of the First Klystron-based X-band Power Source at CERN

3428

J.W. Kovermann, N. Catalan-Lasheras, S. Curt, S. Döbert, G. McMonagle, S.F. Rey, G. Riddone, K.M. Schirm, I. Syratchev, L. Timeo
CERN, Geneva, Switzerland
J.P. Eichner, A.A. Haase, D.W. Sprehn
SLAC, Menlo Park, California, USA
A. Hamdi, F. Peauger
CEA/DSM/IRFU, France

A new klystron based x-band rf power source working at 11.994GHz has been installed and commissioned at CERN in collaboration with CEA Saclay and SLAC for CLIC accelerating structure tests. The system comprises a solid state high voltage modulator, an XL5 klystron developed by SLAC, a cavity based SLED type pulse compressor, the necessary low level rf system including rf diagnostics and interlocks and the surrounding vacuum, cooling and controls infrastructure. The klystron can produce up to 50MW rf pulses of 1500ns pulse width and 50Hz repetition rate. After pulse compression, up to 100MW of rf power at 250ns pulse with are available in the structure test bunker. This paper describes in more detail this setup and the results of the commissioning which was necessary to arrive at the mentioned performance.