Abstracts Brochure - CERN

WEPCH — Poster Session 28-Jun-06 16:00 - 18:00
Numerical Simulation and Optimization of a 3-GHz Chopper/Prebuncher System for the
S-DALINAC
A new source of polarized electrons with an
energy of 100 keV is presently being developed
at the superconducting Darmstadt electron
linear accelerator S-DALINAC for future
N. Somjit, W.F.O. Müller, T. Weiland (TEMF) R. Eichhorn, J. Enders,
H.-D. Gräf, C. Heßler, Y. Poltoratska, A. Richter (TU Darmstadt)
nuclear- and radiation-physics experiments. The pulsed electron beam emitted by the photocathode will be cut to 50
ps by a chopper operated at 3 GHz, and further bunch compression down to 5 ps will be achieved by a two-stage prebuncher
section. The chopper-prebuncher system is based on similar devices used at the Mainz Mikrotron (MAMI)
where the accelerator frequency is slightly smaller (2.4 GHz). For the chopper, a cylindrical resonator operating at
TM110 mode is selected to deflect the electron beam onto an ellipse, i.e., both horizontally and vertically. This is
simply achieved by particular slits on both ends of the resonator. The prebunching system consists of two cavities.
For increasing the longitudinal capture efficiency, the first cavity will be operated at the fundamental accelerator
frequency of the S-DALINAC of 3 GHz, and the second cavity at 6 GHz. The cavities are designed to work at the
TM010 mode and TM020 mode for the fundamental and first harmonic, respectively.
Recent Simulation Results of the Polarized Electron Injector (SPIN) of the S-DALINAC
Recent design and development for a polarized
electron source (SPIN) for the recirculating
superconducting electron linear accelerator
S-DALINAC will be presented. The
B. Steiner, W.F.O. Müller, T. Weiland (TEMF) J. Enders, H.-D. Gräf,
C. Heßler, G. Iancu, A. Richter, M. Roth (TU Darmstadt)
polarized electron beam will be produced by photoemission from an InAlGaAs/GaAs superlattice cathode and will
be accelerated to 100 kV electrostatically. The results of the beam dynamics simulation will be shown in detail. The
start phase space of the electron bunch behind the gun has been approximated. The transverse focusing system
consists of very short quadrupoles. Further main components of the new injector are a Wien filter, a Mott polarimeter,
a chopper-prebuncher system (based on devices used at the Mainz Mikrotron MAMI), and diverse beam diagnostic
tools. For the approximation of the start phase space CST MAFIA is used, and for the beam dynamic simulation
VCode is used.
Beam Dynamics of an Integrated RFQ-drifttube-combination
In the frame of a collaboration with the GSI
in Darmstadt an RFQ-Drifttube-Combina- A. Bechtold, M. Otto, A. Schempp (IAP)
tion for the Heidelberg cancer therapy center
HICAT has been designed, built and successfully beam tested at the IAP Frankfurt. The integration and combination
of both an RFQ and a rebunching drifttube unit inside a common cavity forming one single resonant RF-structure
has been realized for the first time with this machine. The results of the beam measurements and questions about the
beam dynamics simulations of such a combination have been investigated in detail with the code RFQSIM.
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