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.
The Chalk River Superconducting Heavy Ion Cyclotron
A superconducting heavy ion cyclotron has been chosen as the accelerator to extend the range of the Chalk River MP tandem. The tandem-cyclotron combination will accelerate all ions from Li (to 50 MeV/nucleon) through U (to 10 MeV/nucleon). The design of the integrated accelerator facility is underway as well as a full scale modelling program for both the magnet and RF system - the current status of these programs is reported.
Small-angle multiple scattering of ions in the screened Coulomb region: I. Angular distributions
Abstract Bothe's formula for the angular distribution of multiply scattered particles in the small-angle limit has been evaluated numerically for ion-atom potentials of Thomas-Fermi and Lenz-Jensen type, and analytically for power potentials. Special attention is paid to a correct transition from multiple- to single-scattering distributions at small target thicknesses. In general, we find good agreement with results of Meyer that are based on essentially the same physical model, but deviations in the distributions of up to ≈40% occur. Our tabulations comprise a larger range of reduced thicknesses than Meyer's, 0.001 ⩽ τ ⩽ 2000, with a view to both lower absolute thicknesses (e.g. a monolayer) and higher ion energies. Finally, an inversion formula for extracting single-scattering cross sections from measured multiple-scattering distributions is derived.