Magnetic Field and Beam Dynamics Calculations for SUSE
The SuSe magnet system is designed using the program GFUN3D. A small version of this program was connected to a general fit program by means of which the current in the main and trim coils was determined for a given isochronous mean field B¿(r). For beam dynamics calculations with the code GOC accurate fields (¿B¿/B¿ ¿ 1%) were used which were obtained by means of the program GFUN400 where the unique part of the magnet iron is subdivided into 400 elements at maximum. Several coil systems have been investigated. In an alternative design all coils have straigth sections which are easier to manufacture than coils with negative curvature. The main coils have a largest radial extension of 3.08 m. There are 22 correcting coils inside each main coil.
Magnetic field optimization and beam dynamics calculations for SuSe
The superconducting sector magnets of SuSe have been designed using the newly developed program GFUNFIT. By means of this program the deviation of the desired magnetic field from the actual value, which is produced by the magnetic system, can be minimized to within 0.5 Gauss by variation of several parameters, such as conductor current, geometry of conductors and of iron. Varying these parameters, fields with an absolute accuracy of ΔB/B ≲ 1 % have been obtained using the finite-element programs GFUN3D and GETM400. The code GOC has been used to study the beam dynamics in these fields. Two examples for fully stripped heavy ions (q/A = 0.5) with maximum and half maximum final energies (T2/A = 300 MeV/n and 150 MeV/n) are given.
The Beam-Matching System between Pre- and Main-Accelerator for the Van De Graaff-Cyclotron-Combination Vicksi
The matching system connects the Van de Graaff preaccelerator with the isochrounous split pole cyclotron of the heavy ion accelerator combination VICKSI and prepares the beam for injection into the cyclotron. The charge state of the ions is increased by a stripper (gas or carbon foil). This however enlarges the phase space occupied by the beam due to angle- and energy straggling. To minimize this deterioration of beam quality a sharp focus at the stripper is provided in all three dimensions. A longitudinal (time) focus both at the stripper and in the center of the cyclotron is achieved by means of two identical clystron-type bunchers. The magnetic focusing system between the two bunchers contains two doubly achromatic bending units of 90 degrees. Telescopic focusing is used onto the stripper and from the stripper to the second buncher. The last section just before the cyclotron comprises one more bending unit and several quadrupoles for dispersion matching and adapting the horizontal and vertical phase space for injection.