Model Magnet for the Proposed Superconducting Cyclotron at the University of Milan
A project for a superconducting cyclotron for heavy ions has been under study for a couple of years at the Cyclotron Laboratory of the University of Milan. The machine is conceived as a booster for a 16 MV Tandem to be installed at the Laboratories of Legnaro (Padua) of the Italian National Institute for Nuclear Physics (INFN). The K design value is approximately 540, thus allowing maximum energies between approximately 55 MeV/nucleon and approximately 14 MeV/nucleon for light and heavy ions respectively. Pole diameter is 1.8 m and maximum average field should be around 41 Kgauss, to be obtained by a total of 6.5 x 10/sup 6/ Aturns in the superconducting coils. At present a three spiral sector polar configuration is envisaged, with a 7 cm hill gap and 70 cm valley gap. Three dees, in the valleys, should provide a peak accelerating voltage of 100 kV, allowing a 3rd or 9th harmonic operation. While funding for the machine is still under discussion, a program centered upon the construction of a superconducting model magnet and a full scale rf model was started in 1976. The design features of the model magnet, whose construction is now completed, are reported.
Injection Studies for the K=800 Superconducting Cyclotron at M.S.U.
us recall that anticipated maximum beam energies are between 200 MeV/n and 50 MeV/n for fully stripped light ions and heavy ions (uranium) respectively. Minimum energies for the same extreme cases are 50 MeV/n and 5 MeV/n. Operating center field values are between 30 kG and 47 kG, and Z/A values of accelerated particles range from 0.1 to 0.5. Focusing and bending requirements lead to a 41" pole radius machine, and a three sector geometry, having 46 wide hills, with an unusually tight spiral, i.e. with a constant of 1/13 rad/inch.
Focusing properties of superconducting cyclotron magnets
Abstract Superconducting main coils combined with conventional sectored iron pole tips constitute a promising design configuration for a new generation of compact, low-cost, heavy-ion cyclotrons. This paper gives results of focusing strength calculations for such cyclotrons for a variety of possible pole tips. The focusing is found to be highly sensitive to the average strength of the magnetic field, moderately sensitive to the magnet gap in the hills, and relatively independent of the number of sectors, the relative width of hill and valley and the magnet gap in the valleys. Spiraling of the magnet pole tips increases the focusing but substantially less than expected. Several of these properties are strikingly different from the corresponding properties of conventional low field magnets. The focusing limit of high field magnets leads to a linear dependence of the energy per nucleon on the charge-to-mass ratio of the ion over much of the operating range which contrasts with the usual quadratic dependence.