IPAC2011 - List of Authors (Lotz, M.)

Paper	Title	Page
MOPS029	Experiments with a Fast Chopper System for Intense Ion Beams	664
	H. Dinter, M. Droba, M. Lotz, O. Meusel, I. Müller, D. Noll, U. Ratzinger, K. Schulte, C. Wagner, C. Wiesner IAP, Frankfurt am Main, Germany
	Chopper systems are used to pulse charged particle beams. In most cases, electric deflection systems are used to generate beam pulses of defined lengths and appropriate repetition rates. At high beam intensities, the field distribution of the chopper system needs to be adapted precisely to the beam dynamics in order to avoid aberrations. An additional challenge is a robust design which guarantees reliable operation. For the Frankfurt Neutron Source FRANZ, an E×B chopper system is being developed which combines static magnetic deflection with a pulsed electric field in a Wien filter configuration. It will generate proton pulses with a flat top of 50 ns at a repetition rate of 250 kHz for 120 keV, 200 mA beams. For the electric deflection, pre-experiments with static and pulsed fields were performed using a helium ion beam. In pulsed mode operation, ion beams of different energies were deflected with voltages of up to ±6 kV and the resulting response was measured using a beam current transformer. A comparison between experiments and theoretical calculations as well as numerical simulations are presented.

WEPS040	The Driver Linac of the Neutron Source FRANZ	2577
	U. Ratzinger, B. Basten, L.P. Chau, H. Dinter, M. Droba, M. Heilmann, M. Lotz, O. Meusel, I. Müller, D. Mäder, Y.C. Nie, D. Noll, H. Podlech, A. Schempp, W. Schweizer, K. Volk, C. Wiesner, C. Zhang IAP, Frankfurt am Main, Germany
	FRANZ is under construction at the Goethe University Frankfurt. A 2MeV ± 100 keV proton beam will produce 1 keV to 200 keV neutrons on a Li7 target. Experiments are planned in the field of nuclear astrophysics as well as in applied physics. A dc operated proton source with a maximum beam current of 200 mA was successfully beam tested end of 2010. FRANZ will have two experimental areas: One for activation experiments with cw proton beams of a few mA generating a usable neutron flux of some 10 billion per square cm per second, the other one for 250 kHz, 1 ns short neutron bunches generated by 1 ns proton pulses of a few Ampere beam current. A special 2 MeV, 175 MHz high current cavity is realized at present as a RFQ-DTL combination. Novel techniques have been invented to reach the needed pulsed target beam current by a bunch compressor system. Work supported by HICforFAIR and GSI.

Paper

Title

Page

Experiments with a Fast Chopper System for Intense Ion Beams

664

H. Dinter, M. Droba, M. Lotz, O. Meusel, I. Müller, D. Noll, U. Ratzinger, K. Schulte, C. Wagner, C. Wiesner
IAP, Frankfurt am Main, Germany

Chopper systems are used to pulse charged particle beams. In most cases, electric deflection systems are used to generate beam pulses of defined lengths and appropriate repetition rates. At high beam intensities, the field distribution of the chopper system needs to be adapted precisely to the beam dynamics in order to avoid aberrations. An additional challenge is a robust design which guarantees reliable operation. For the Frankfurt Neutron Source FRANZ, an E×B chopper system is being developed which combines static magnetic deflection with a pulsed electric field in a Wien filter configuration. It will generate proton pulses with a flat top of 50 ns at a repetition rate of 250 kHz for 120 keV, 200 mA beams. For the electric deflection, pre-experiments with static and pulsed fields were performed using a helium ion beam. In pulsed mode operation, ion beams of different energies were deflected with voltages of up to ±6 kV and the resulting response was measured using a beam current transformer. A comparison between experiments and theoretical calculations as well as numerical simulations are presented.

WEPS040

The Driver Linac of the Neutron Source FRANZ

2577

U. Ratzinger, B. Basten, L.P. Chau, H. Dinter, M. Droba, M. Heilmann, M. Lotz, O. Meusel, I. Müller, D. Mäder, Y.C. Nie, D. Noll, H. Podlech, A. Schempp, W. Schweizer, K. Volk, C. Wiesner, C. Zhang
IAP, Frankfurt am Main, Germany

FRANZ is under construction at the Goethe University Frankfurt. A 2MeV ± 100 keV proton beam will produce 1 keV to 200 keV neutrons on a Li7 target. Experiments are planned in the field of nuclear astrophysics as well as in applied physics. A dc operated proton source with a maximum beam current of 200 mA was successfully beam tested end of 2010. FRANZ will have two experimental areas: One for activation experiments with cw proton beams of a few mA generating a usable neutron flux of some 10 billion per square cm per second, the other one for 250 kHz, 1 ns short neutron bunches generated by 1 ns proton pulses of a few Ampere beam current. A special 2 MeV, 175 MHz high current cavity is realized at present as a RFQ-DTL combination. Novel techniques have been invented to reach the needed pulsed target beam current by a bunch compressor system.
Work supported by HICforFAIR and GSI.